COVID-19 Vaccine Effectiveness: Live Updates on Pfizer, Moderna, Novavax, and More

In the U.S., the Pfizer and Moderna COVID-19 vaccines are fully FDA approved for people ages 12 and older, and authorized for kids as young as 6 months old. The Novavax vaccine is authorized for use through an emergency use authorization (EUA), which allows it to be used without being fully approved. 

All three vaccines have been shown to be safe and effective against COVID. But in an ever-changing environment, are they still effective over time and against new virus variants (mutations)?

As more people receive the COVID vaccines and as the virus evolves, it’s important to ensure that they continue to provide protection against COVID. New studies will look at how well the vaccines work in different groups (e.g., healthcare workers, older adults), if protection goes down over time, and if they’re still effective against concerning variants. 

Here, we’ll be tracking the latest COVID vaccine effectiveness news, especially as updated 2024-2025 COVID vaccines are now recommended for people ages 6 months and older. Check back with GoodRx for updates.

CDC model forecasts that 2024-2025 COVID vaccines will help prevent more hospitalizations

September 3, 2024

Broad vaccine recommendation may help prevent more than 30,000 U.S. hospitalizations this season

A recent CDC model suggests that increased 2024-2025 COVID vaccine uptake would lead to fewer hospitalizations from COVID.

If people ages 6 months and older are recommended to receive the vaccines (a universal recommendation) — rather than solely high-risk individuals — an additional 28,000 to 31,000 hospitalizations could be prevented in the U.S. over the next year. This number jumps to more than 110,000 prevented hospitalizations when compared to a scenario where there is no vaccine recommendation.

This data is part of why the CDC recommended 2024-2025 COVID vaccines for everyone ages 6 months and older — not just those who are at high risk for severe illness. To read more about the CDC’s analysis, click or tap here. 

Keep in mind: This data is based on predictive modeling. This is because the 2024-2025 vaccines haven’t been widely administered yet. These predictions are also based on the assumption that the vaccines will be about 75% effective against hospitalization and that a similar number of people will receive the vaccines as last year.

Protection against COVID-related hospitalization is likely highest in the weeks following vaccination

September 3, 2024

EXPERT PICKS: WHAT TO READ NEXT

• Navigating vaccine updates: As the coronavirus evolves, so do the COVID-19 vaccines. Get the latest updates on COVID vaccine authorizations and approvals here.

• How they compare: Three COVID vaccines are available in the U.S. But is one better than the other for your next dose?

• Going beyond vaccines: Discover all you need to know about COVID treatments and preventative medications with our comprehensive guide.

European study suggests that XBB.1.5-targeted COVID vaccines were nearly 70% effective against hospitalization within the first month

A European study published in August 2024 found that XBB.1.5-targeted Pfizer, Moderna, and Novavax vaccines were most effective at preventing hospitalization in adults in the weeks following vaccination. These are the vaccines that were recommended during the 2023-2024 respiratory illness season.

In this 3-month study, the vaccines were nearly 50% effective at preventing hospitalization from COVID. However, they were nearly 70% effective within the first month of vaccination. Their effectiveness dipped down to about 40% after roughly 3 months.

While the 2023-2024 vaccines are no longer recommended in the U.S., the 2024-2025 vaccines that target newer viral variants may convey similar protection. 

To read more about this study, click or tap here.

COVID-19 vaccines may help prevent certain heart- and blood- related health complications

May 13, 2024

New study finds that the COVID-19 vaccines may lower the risk of certain heart problems by roughly 80%

Some evidence shows that COVID-19 can increase the risk of blood clots and related heart problems. This likely stems from the inflammation it causes. But a recent European study published in Heart found that COVID-19 vaccines can help lower this risk. 

More than 20 million people were included in this study. Half were previously vaccinated against COVID-19, while the other half were not. The vaccines were found to reduce the risk of developing blood clots in a vein, blood clots in an artery, and heart failure.

For instance, within 30 days of having COVID-19, those who received a vaccine had a 78% lower risk of developing a blood clot in a vein, 47% lower risk of a blood clot in an artery, and 55% lower risk of heart failure. Fast forward 3 to 6 months later, these risks were reduced by 47%, 28%, and 39%, respectively.

To read more about this study — including how well the vaccines worked up to 1 year after infection — click or tap here.

More data suggests that 2023-2024 COVID-19 vaccines help prevent urgent care visits, ER visits, and hospitalizations

March 6, 2024

The updated COVID vaccines may slash these risks by more than half

Another CDC study published data that estimates the effectiveness of the 2023-2024 COVID vaccines among adults ages 18 and older. This large study analyzed medical visits that took place between September 2023 and January 2024. For context, these updated vaccines were first recommended in September 2023. Here’s a snapshot of the results.

Updated COVID-19 vaccine effectiveness against urgent care and ER visits:

• Within 2 months of updated dose: 51%

• About 2-4 months after updated dose: 39%

Updated COVID-19 vaccine effectiveness against hospitalization:

• Within 2 months of updated dose: 52%

• About 2-4 months after updated dose: 43%

To read more about these findings, click or tap here. 

Updated 2023-2024 COVID-19 vaccines can help prevent severe illness

February 1, 2024

Updated Pfizer vaccine protects against hospital admissions, ER visits, and more

In September 2023, the FDA and CDC approved and recommended updated 2023-2024 COVID-19 vaccines. They target a more recent viral variant called XBB.1.5.

In a recent preprint study, one dose of an updated Pfizer vaccine in adults was found to provide added protection against severe illness compared to adults who didn’t receive one. People who received an updated Pfizer vaccine were:

• 63% less likely to go to the hospital

• 58% less likely to go to the ER or urgent care center

• 58% less likely to need general outpatient treatment

However, this information hasn’t been peer reviewed. And the Moderna and Novavax vaccines weren’t included in this study. To read more about this research, click or tap here.

Updated Pfizer vaccine helps protect older adults from severe illness, according to Dutch researchers

New Dutch research suggests that among previously vaccinated adults ages 60 and older, a dose of the updated Pfizer vaccine helps protect against severe illness. 

In this study, the vaccine was roughly 71% effective against hospitalization and 73% effective against intensive care unit (ICU) admissions. It was slightly more effective against hospitalization for adults ages 75 years and older compared to those ages 60 to 74.

This data also isn’t peer reviewed, though, and other COVID-19 vaccines weren’t included in the analysis. To read more about this research, click or tap here.

COVID-19 vaccines may help prevent long COVID

February 1, 2024

Multiple studies show a benefit in both kids and adults

Growing evidence is showing that COVID-19 vaccines help prevent long COVID, or symptoms that persist for months after initially testing positive for COVID-19.

These are some recent findings:

• A large European study found that getting vaccinated for COVID-19 helps reduce the risk of developing long COVID by up to 52% in adults.

• A study published in Pediatrics found that fully vaccinated kids ages 5 to 17 years old have a 42% lower risk of developing a long COVID diagnosis, calling it a “moderate protective effect.”

More data finds that updated booster shots reduce the risk of hospitalization and death among older adults

May 8, 2023

Updated boosters were 72% effective against hospitalization, 68% effective against death

Additional published data from Israel suggests that bivalent (updated) booster shots can help protect against severe COVID-19 in older adults. 

Compared to no booster, updated booster shots were roughly 72% effective against hospitalization and 68% effective against COVID-19-related death. In the study, 541 people who didn’t receive an updated booster ended up going to the hospital; this is compared to 32 people who did receive one.

Everyone in the study was aged 65 years or older, and it took place between September 2022 and January 2023. Nearly 135,000 people in the study received an updated booster shot, and over 435,000 did not. However, this was a retrospective, medical record-based study.

What this means: If you’re eligible to receive an updated booster shot (or a second updated booster), the extra dose may lead to extra protection against severe COVID-19.

Keep in mind: This study only included adults ages 65 years and older. It didn’t include anyone ages 64 or younger. COVID-19 vaccines are still effective for younger adults, but this study’s data doesn’t speak to that population.

To read more about this update, click or tap here.

Time of day may impact vaccine effectiveness

May 8, 2023

Retrospective study suggests midday vaccine appointments may be most beneficial

Another recent retrospective study found that COVID-19 vaccine effectiveness may potentially fluctuate by 8% to 25% depending on what time you receive the vaccine. The study's authors linked this to the circadian rhythm of our immune system.

People who were vaccinated in the late morning and early afternoon generally had fewer breakthrough infections — COVID-19 infections despite being fully vaccinated. People vaccinated in the evening (between 4:00PM and 7:00PM) had the most breakthrough infections. The largest benefits from daytime vaccination were seen among people younger than 20 years old and adults older than 50.

This study analyzed health plan data from over 1.5 million people over 12 years old in Israel. Over 99% of people received the original Pfizer vaccine.

What this means: Some data suggests that it may be better to receive a COVID-19 vaccine during the day instead of the evening.

Keep in mind: This data is preliminary. It’s not considered broad guidance for when to receive your vaccine. Do what works best with your schedule.

To read more about this update, click or tap here.

Early evidence suggests that updated (bivalent) booster shots help protect against newer Omicron subvariants

February 6, 2023

Lab data finds that the updated Pfizer vaccine helps neutralize BQ.1.1 and XBB.1

Recent lab data published in The New England Journal of Medicine found that the updated Pfizer vaccine helps protect against widely-circulating Omicron subvariants, including BQ.1.1 and XBB.1.

Vaccinated adults ages 55 and older were included in this study. All participants received three doses of the original Pfizer vaccine. Some people then received a fourth dose of the original vaccine, but others received the updated Pfizer shot instead.

Compared to a fourth dose of the original vaccine, the updated Pfizer vaccine led to higher Omicron-fighting antibody levels against multiple Omicron subvariants, such as BA.4.6, BQ.1.1, and XBB.1. It also led to higher responses against BA.2.75.2 and the original strain of the virus. This was the case in both people with and without prior infection receiving the updated vaccine. But the responses were generally higher among people who previously tested positive for COVID-19.

• What this means: Even though newer Omicron subvariants can interfere with vaccine effectiveness, an updated Pfizer booster shot still appears to generate a protective antibody response.

• Keep in mind: Only the Pfizer vaccine was included in this study. The Moderna vaccine wasn’t included in the analysis.

To read more about this update, click or tap here.

Updated Pfizer and Moderna vaccines help protect against symptomatic illness attributed to XBB and XBB.1.5 subvariants

A recent CDC study suggests that vaccinated adults that receive an updated Pfizer or Moderna booster shot may be less likely to develop symptomatic COVID-19 from newer Omicron subvariants.

Fully vaccinated adults who received a bivalent booster had a vaccine effectiveness of at least 40% against symptomatic XBB and XBB.1.5 within 3 months of vaccination. Vaccine effectiveness was nearly 50% among adults ages 18 to 49. This was compared to adults that received two to four doses of an original vaccine but not an updated booster.

This study took place between December 2022 and January 2023. Results from over 29,000 tests were gathered from pharmacies and other community testing sites around the U.S., primarily in at-risk areas.

• What this means: Early data suggests that bivalent COVID-19 vaccines offer protection against Omicron subvariants like XBB and XBB.1.5. It’s recommended to get vaccinated if and when you’re eligible.

• Keep in mind: Vaccine effectiveness against symptomatic illness was slightly lower for adults ages 50 and older.

To read more about this update, click or tap here.

CDC publishes new data about updated (bivalent) booster shot effectiveness against different medical encounters

January 12, 2023

Updated booster shots more than 50% effective against urgent care visits, emergency room visits, and hospitalizations

According to a large, multi-state study, updated Pfizer and Moderna vaccines can help prevent severe COVID-19 likely caused by newer Omicron subvariants. In the study, adults who received an updated booster shot following two to four doses of an original (monovalent) vaccine were less likely to go to an urgent care center, emergency room, or hospital due to the illness. 

Compared to people who haven’t been vaccinated, the updated booster shots were 56% effective against urgent care and emergency room (UC/ER) visits and 57% effective against hospitalizations. 

Compared to people who received an original vaccine within the last few months, the updated booster shots were about 31% effective against UC/ER visits and 38% effective against hospitalizations. Vaccine effectiveness was higher for both categories among people who hadn’t received an original vaccine for 11 months or longer. 

• What this means: Data continues to suggest that updated booster shots help protect against severe COVID-19 caused by newer viral variants.

• Keep in mind: This study was conducted between September and November 2022. This time frame includes when subvariants like Omicron BA.5 and BQ.1/BQ.1.1 were widely circulating.

To read more about this study, click or tap here. 

Updated booster shots further reduce the risk of hospitalization among older adults

A different CDC study found that updated booster shots help reduce the risk of hospitalization among adults ages 65 and older. 

Compared to no vaccines, updated booster shots were considered 84% effective against hospitalization when they were administered to people at least 1 week prior to getting sick. They were also 73% more effective against hospitalization when compared to people who only received doses of the original COVID-19 vaccines.

• What this means: If you or a loved one are ages 65 or older, there’s increasing evidence that shows an updated COVID-19 booster shot can help keep you out of the hospital.

• Keep in mind: This data was collected between September and November 2022, reflecting a time period dominated by subvariants like Omicron BA.5 and BQ.1/BQ.1.1.

To read more about this study, click or tap here.

New study calculates number of infections and severe complications prevented by COVID-19 vaccines

December 14, 2022

Since December 2020, COVID-19 vaccines have helped prevent millions of infections, hospitalizations, and deaths in the U.S.

A U.S. modeling-based study found that COVID-19 vaccines helped prevent about 120 million infections, 18 million hospitalizations, and 3 million deaths between December 2020 and November 2022. Without them, the study authors estimate that the U.S. would have experienced up to 1.5 times more infections and 4 times more hospitalizations and deaths during this same time period.

As of mid-December 2022, CDC data shows that there have been more than 99 million infections, 5 million hospitalizations, and 1 million deaths due to COVID-19 in the U.S. 

• What this means: COVID-19 vaccines have been available in the U.S. for 2 years. During this time, they helped prevent COVID-19 infections and severe complications.

• Keep in mind: This projected data is from a computer model. These numbers aren’t exact — they’re just an estimate.

To read more about this update, click or tap here. 

Additional evidence finds that updated Pfizer and Moderna boosters help improve protection against Omicron

November 30, 2022

Bivalent Moderna booster shots lead to significantly higher protective antibody levels

In a recent press release, Moderna announced that their updated (bivalent) booster shot provides a superior protective antibody response against Omicron compared to their original booster. Their phase 2/3 study found that the updated vaccine generates higher Omicron-fighting antibody levels by about 5- to 6-fold. This superiority remained consistent for at least 3 months post-vaccination.

The updated booster is also active against BQ.1.1, one of the most widely circulating subvariants in the U.S. at this time.

• What this means: If you’re eligible for a booster shot and want the Moderna vaccine, it’s recommended to get an updated version rather than the original. 

• Keep in mind: These findings come from lab-based data. They don’t directly represent the vaccine’s ability to prevent symptomatic or severe COVID-19.

To read more about this update, click or tap here.

Bivalent Pfizer booster shots improves protective antibody levels, especially in adults ages 55 and older

Pfizer recently released more data that shows their updated booster shot fights the Omicron variant better than their original vaccine. After 1 month, among adults ages 55 and older, the updated vaccine led to about a 4-fold higher Omicron-fighting antibody response compared to the original (13-fold versus 3-fold, respectively).

In this phase 2/3 study, there wasn’t a comparator group for people younger than 55 years old. But people ages 18 to 55 years old who received the updated Pfizer booster saw more than a 9-fold rise in Omicron-fighting antibody levels.

In a different preprint study, the updated Pfizer vaccine was also shown to be more active against the fast-spreading BQ.1.1 Omicron subvariant.

• What this means: If you’re eligible to receive a booster shot and want the Pfizer vaccine, the updated version is recommended over the original.

• Keep in mind: This information comes from lab-based data. Researchers will continue to study the vaccine’s effectiveness against symptomatic and severe COVID-19.

To read more about this update, click or tap here.

CDC study finds that bivalent Pfizer and Moderna boosters help ward off symptomatic illness

A new CDC study revealed that updated Pfizer and Moderna boosters helped prevent symptomatic COVID-19 during the time of Omicron’s predominance.

In this study, people with symptomatic illness were tested at U.S. pharmacies between September and November 2022. Compared to people who previously received two to four doses of the original vaccines, people who received an updated booster shot were significantly less likely to test positive and have symptoms of COVID-19.

• What this means: It’s important to stay up to date with your COVID-19 vaccinations. At this time, everyone ages 5 and older are eligible for an updated booster shot.

• Keep in mind: You can get an updated COVID-19 booster shot if it’s been at least 2 months since your last dose.

To read more about this update, click or tap here.

Bivalent Moderna COVID-19 vaccine appears to provide a better response to Omicron than the original vaccine

October 13, 2022

Early study results find that the vaccine leads to a higher antibody response against Omicron and original virus

Researchers studying the bivalent (updated) Moderna vaccine recently published findings in The New England Journal of Medicine that suggest the bivalent vaccine is better optimized for the Omicron variant than the original vaccine formulation.

Compared to the original vaccine, the bivalent vaccine provided a superior neutralizing antibody response (virus-fighting antibody response) against Omicron among people who haven’t tested positive for COVID-19 in the past. It also provided a higher response to the original virus strain in people who previously tested positive. At the same time, it led to a comparable response to the original virus among people without prior infection.

Over 800 people are included in this ongoing phase 2/3 clinical trial. The vaccine was administered as a second booster shot to everyone in the study. These results were collected 28 days after each person in the study received their booster dose.

• What this means: The bivalent Moderna vaccine appears to lead to an improved antibody response against the Omicron variant.

• Keep in mind: There still isn’t much data about how well the new bivalent vaccines work against Omicron. And while this study provides some early insight about the Moderna vaccine, it didn’t look at the effects of the bivalent Pfizer vaccine.

To read more about this update, click or tap here. 

Scottish study finds that COVID-19 vaccines can help reduce the risk of complications from long COVID

October 13, 2022

COVID-19 vaccines help lower the risk of taste changes, smell changes, and more

A recent survey-based study in Scotland studied the health effects of long COVID over a 6- to 18-month time period. Among other endpoints, researchers looked to see how COVID-19 vaccines could help prevent or reduce symptoms of long COVID. 

In the study, getting vaccinated prior to testing positive for COVID-19 helped reduce the risk of persistent symptoms related to long COVID. Compared to people who weren’t vaccinated, vaccinated people reported these symptoms less frequently:

• Changes in smell or taste

• Difficulty hearing

• Appetite changes

• Coordination problems

• Confusion

• Concentration problems

• Symptoms of anxiety or depression

Although this study wasn’t conducted in the U.S., many people were involved in these findings. Over 96,000 participants were included.

• What this means: Researchers are still learning about long COVID. However, this data suggests that getting vaccinated against COVID-19 can help prevent certain symptoms related to long COVID.

• Learn more: If you want to know more about long COVID, another GoodRx Health resource covers the latest developments related to this condition. 

To read more about this update, click or tap here.

CDC study finds that second booster shots help prevent severe COVID-19 and death in nursing home residents

October 13, 2022

After 2 months, second Pfizer or Moderna booster shots were up to 90% effective against death from COVID-19

A large CDC study recently found that second Pfizer or Moderna booster shots can help prevent severe outcomes among U.S. nursing home residents during the ongoing Omicron wave. 

In this recent study of over 9,500 nursing home residents, when compared to one booster shot, second booster shots were about 74% effective against hospitalization and death from COVID-19 after 2 months. They were also about 90% effective against death alone. However, in this study, they were about 26% effective at preventing new infections.

• What this means: The Pfizer and Moderna vaccines continue to offer a high degree of protection against hospitalization and death from COVID-19.

• Keep in mind: This study didn’t analyze the effects of the bivalent (updated) COVID-19 vaccines. The original Pfizer and Moderna vaccines were the ones included in the study.

To read more about this update, click or tap here. 

Pfizer and Moderna vaccines shown to help reduce the risk of death for people with heart failure

September 15, 2022

Danish research finds that the benefits of mRNA vaccines outweigh the risks in this population

Recent research presented at a European Society of Cardiology meeting found that mRNA vaccines (Pfizer and Moderna) can help lower the risk of death for people living with heart failure. 

In this research, the effects of the mRNA vaccines were analyzed in about 100,000 people with heart failure. Compared to unvaccinated people, the mRNA vaccines helped slightly lower the risk of death due to any cause. And they weren’t seen to worsen the risk of myocarditis, more severe heart failure, or blood clots in study participants, either. 

• What this means: mRNA vaccines have been connected to certain heart-related complications in the past, but this research found that there shouldn’t be a concern about cardiovascular side effects from mRNA vaccines in people with heart failure. 

• Keep in mind: This research only analyzed the Pfizer and Moderna vaccines. The Novavax and J&J vaccines weren’t included.

To read more about this update, click or tap here.

Pfizer and Moderna booster shots help improve protection against COVID-19 for older adults

September 15, 2022

mRNA booster shots appear to help lower the risk of multiple COVID-19-related complications

A recent Singapore-based study published in the Annals of Internal Medicine found that a second COVID-19 booster shot (fourth total dose) in adults, ages 80 and older, can help lower the risk of COVID-19-related complications. 

In the study, compared to just one booster shot, an extra mRNA booster was about 22% effective at preventing symptomatic COVID-19, 63% effective at preventing severe illness, and 55% effective at preventing hospital admissions. About 40,000 people were included in the study, and it was conducted while the Omicron variant was predominant. 

• What this means: It’s recommended to get your next booster shot when you’re eligible to receive it, especially if you’re an older adult. 

• Keep in mind: This study was conducted before the Omicron-specific vaccines were available. For Fall 2022, Omicron-specific vaccines are recommended in the U.S. for booster shots. 

To read more about this update, click or tap here.

Recent Omicron subvariants appear to lower COVID-19 vaccine effectiveness, but booster shots help improve protection

August 1, 2022

CDC study finds that first and second booster shots help improve protection against moderate and severe illness in eligible people

A recent CDC study published new findings that provide early evidence of how the Pfizer and Moderna vaccines (mRNA vaccines) are affected by different Omicron subvariants, particularly BA.1, BA.2, and BA.2.12.1. It also provided more information about how vaccine effectiveness can change over time and with one or two booster shots. 

Some of the key findings about booster shots are summarized in the table below. 

The study also published findings about vaccine effectiveness against urgent care and emergency room visits — not just hospitalizations. The trends were relatively similar for both situations. 

• What this means: Vaccine effectiveness tends to go down over time. So, it’s recommended to get COVID-19 booster shot(s) if and when you’re eligible for them. 

• Keep in mind: This data doesn’t reflect vaccine effectiveness against the Omicron BA.5 subvariant, which currently makes up more than 80% of U.S. COVID-19 cases. These reported percentages may also be affected by immunity gained from previous COVID-19 infections. 

To read more about this update, click or tap here. 

New study suggests that COVID-19 vaccines have saved the lives of over 235,000 U.S. adults

August 1, 2022

Modeling study also suggests the vaccines have prevented millions of positive cases and COVID-19-related hospitalizations

Since the start of the COVID-19 pandemic, there have been over 90 million positive cases, about 37,000 hospitalizations, and more than 1 million COVID-19-related deaths in the U.S. But according to a new estimate, these numbers would be higher without COVID-19 vaccines. 

A modeling study recently published in JAMA Network Open found that between December 2020 and September 2021, COVID-19 vaccines prevented about 27 million infections, 1.6 million hospitalizations, and 235,000 deaths among U.S. adults. 

People included in the study received two doses of either the Pfizer or Moderna vaccines or one dose of the J&J vaccine. Booster shots or additional doses weren’t included in the study.

• What this means: Even though COVID-19 vaccine effectiveness is always evolving, COVID-19 vaccines have been shown to protect against new infections and moderate to serious illness.

• Keep in mind: These findings are a bit outdated. This study was published recently, but it used data from December 2020 to September 2021. Children, booster shots, and additional doses weren’t factored in, either.

To read more about these findings, click or tap here. 

Pfizer and Moderna studying Omicron-specific booster shots

July 1, 2022

Omicron-specific booster shots appear to generate positive immune responses in early lab studies

Pfizer recently announced positive early data for two updated versions of their COVID-19 vaccine. One candidate is a refreshed Omicron-based vaccine, and the other candidate combines the current Pfizer vaccine with a vaccine that targets the Omicron BA.1 subvariant. 

In lab tests, a fourth dose of the Omicron-specific vaccine (3 original shots plus one Omicron-specific shot) led to a 13-fold boost in protective antibody levels against Omicron after 1 month. The combined vaccine candidate led to a 9-fold increase. Higher dose versions of the vaccines led to greater responses. 

Early in June, Moderna announced similar data for their own Omicron-specific booster shot. Their updated vaccine candidate combines the current Moderna vaccine with a vaccine that targets Omicron. In lab tests, a booster shot of the vaccine candidate improved protective antibody levels 8-fold after 1 month. 

• What this means: Current COVID-19 vaccines target the original SARS-CoV-2 virus. These updated vaccine candidates are looking to target a variant of the virus that has been dominant in the U.S. for months.

• Keep in mind: An FDA expert vaccine panel recently voiced their support for developing Omicron-specific booster shots. Health officials would like updated vaccines ready by later this year. 

To read more about this update, click or tap here. 

Novavax COVID-19 vaccine candidate reported to be about 90% effective at preventing COVID-19

June 10, 2022

FDA expert committee recently reviewed the vaccine’s safety and effectiveness data and recommended its authorization

About 1 year ago, the Novavax COVID-19 vaccine candidate was initially reported to be about 90% effective at preventing COVID-19 in a key clinical trial. Fast forward to today, its effectiveness is still relevant. After reviewing this data, and other related data, an FDA committee of vaccine experts recently voted to recommend the authorization of this vaccine in adults.

The bulk of this data was collected between December 2020 and September 2021. This is before the Delta and Omicon variants became predominant in the U.S. But according to an FDA briefing document, the Novavax vaccine is “more likely than not” to offer some protection against newer variants, including Omicron. Plus, additional data released in December 2021 from adolescent and booster shot studies also suggests the Novavax vaccine can create an immune response against the Omicron variant. 

• What this means: The Novavax vaccine appears to be an effective option to fight COVID-19, but it’s still being evaluated. 

• Keep in mind: The Novavax vaccine still isn’t authorized for use in the U.S. But depending on the results of upcoming FDA and CDC decisions, it may become available in the near future. 

To read more about this update, click or tap here. 

Getting a Pfizer or Moderna vaccine during pregnancy may benefit newborn children

June 3, 2022

Recent Norwegian study suggests getting a mRNA vaccine in the 2nd or 3rd trimester can help protect newborns against COVID-19 infection

Organizations like the CDC already recommend COVID-19 vaccines for pregnant women. But a large new study from Norway found that mRNA vaccines may help protect newborns, too.

This study analyzed over 21,000 newborns born between September 2021 and February 2022. Of these, about 45% were born to mothers who received a second or third mRNA vaccine dose during their second or third trimesters of pregnancy.

Before January 1, 2022, less than 1% of newborns born to vaccinated mothers tested positive for COVID-19 during their first 4 months of life. This is compared to about 1.5% of newborns who were born to unvaccinated mothers.

After January 1, 2022 — which is the time of Omicron’s predominance — protection slightly went down. But the vaccines still offered some protection. About 4% of newborns born to vaccinated mothers, and 5% of newborns born to unvaccinated mothers, tested positive for COVID-19 during their first 4 months of life. 

• What this means: If you’re pregnant, consider getting vaccinated and boosted as recommended by your healthcare provider. This protection may also help protect your newborn child. 

• Keep in mind: This study was conducted in Norway using registry data. It didn’t take place in the U.S., and it wasn’t a clinical trial.

To read more about this update, click or tap here. 

More Pfizer vaccine effectiveness data is available for young kids aged 6 months through 4 years old

June 3, 2022

Pfizer booster shot estimated to be about 80% effective at preventing symptomatic COVID-19 in young kids

Pfizer recently posted more data that speaks to its COVID-19 vaccine’s effectiveness in kids ages 6 months through 4 years old. 

In their recent phase 2/3 study, three doses of their low-dose vaccine were found to be about 80% effective at preventing symptomatic COVID-19. In their press release, Pfizer stated that this protection is similar to protection offered by the normal-dose vaccine given to adults. 

Close to 1,700 kids were included in the study, and these booster shots were given during the time of Omicron’s predominance. This data is expected to be part of Pfizer’s rolling submission to get their vaccine authorized in young children. It’s expected to be reviewed by one of the FDA’s expert advisory committees on June 15. 

• What this means: Getting vaccinated and boosted with the Pfizer vaccine appears to be a potentially effective option for young kids. 

• Keep in mind: The Pfizer vaccine is currently authorized for people ages 5 and older. It’s not yet authorized for kids ages 4 and younger. 

To read more about this update, click or tap here. 

More vaccine effectiveness data is now available for young kids, ages 5 to 11 years old

May 2, 2022

Pfizer booster shot appears to generate ‘strong immune response’ in kids

Pfizer recently announced phase 2/3 study results that suggest their low-dose (10 mcg) booster shot can generate a high level of protection against COVID-19 in kids, ages 5 to 11. 

More specifically, protective (neutralizing) antibody levels appear to respond well to the booster shot. The data showed that the vaccine can provide a 36-fold boost in Omicron-fighting antibody levels. The Omicron variant, including the Omicron BA.2 subvariant, have been predominant strains in the U.S. over the past several months. 

• What this means: Given this positive data, Pfizer has submitted a request for their low-dose vaccine to be authorized as a booster shot in kids ages 5 through 11 years old. Currently, people ages 12 and older can receive a Pfizer booster shot.

• Keep in mind: The Pfizer vaccine is already authorized for kids ages 5 and older as a primary series. It’s currently the only COVID-19 vaccine authorized for this purpose.

To read more about this update, click or tap here. 

Pfizer vaccine estimated to reduce the risk of hospitalization from Omicron by about 68% among kids, ages 5 to 11 years old

Recent data published in The New England Journal of Medicine suggests that two doses of the Pfizer vaccine helped protect kids and adolescents from hospitalization during Omicron’s early stages (December 2021 to February 2022). 

In kids, ages 5 to 11 years old, the vaccine was about 68% effective against hospitalization during this time. By comparison, the vaccine was about 40% effective against hospitalization among adolescents ages 12 to 18 years old. However, adolescents in the study received their vaccines earlier than the younger group. COVID-19 vaccine effectiveness is known to wane over time. 

Plus, data from a recent CDC study had similar results. Between December 2021 and February 2022, unvaccinated kids, ages 5 to 11 years old, were twice as likely to be hospitalized than their vaccinated counterparts. 

• What this means: The Pfizer vaccine can help protect kids and adolescents against COVID-19-related hospitalization during Omicron’s initial wave.

• Keep in mind: Booster shot data is not reflected by this data. Kids under the age of 12 aren’t currently authorized to receive booster shots, and adolescents in the first study only received two vaccines as part of their primary vaccination series. 

To read more about this update, click or tap here. 

Pfizer and Moderna vaccines can help prevent hospitalization in people previously infected with COVID-19

May 2, 2022

Booster shots thought to be about 68% effective at preventing hospital visits during the Omicron wave following a previous infection

A recent CDC study found that getting vaccinated after testing positive for COVID-19 can further reduce your chances of COVID-19-related hospitalization. 

During the time of Omicron’s predominance, two doses of the Pfizer or Moderna vaccines were found to be about 35% effective at preventing reinfection that led to hospitalization. This effectiveness jumped up to about 68% after getting a booster dose. The researchers found that the extra protection conveyed by a booster shot was similar to the protection the vaccines provided during the Delta wave (about 58%). 

• What this means: A prior infection helps generate some immunity to the virus, but getting vaccinated and boosted provides extra protection. 

• Keep in mind: Getting vaccinated is the safest way to protect yourself from complications from COVID-19. 

To read more about this update, click or tap here. 

New analysis suggests many COVID-19-related deaths during Delta and Omicron waves could have been prevented with vaccination

May 2, 2022

Report estimates that over 200,000 U.S. COVID-19 deaths could have been prevented with vaccination

A new report from the Peterson Center on Healthcare and Kaiser Family Foundation (KFF) estimates that about 234,000 adult deaths could have been prevented with primary COVID-19 vaccines between June 2021 and March 2022. Using CDC and KFF data, unvaccinated adults from 25 U.S. jurisdictions were the focus of this analysis.

This is just a predictive estimate, but researchers from the study say that this data shows COVID-19 vaccines can help prevent death from the virus. As of late April 2022, nearly 1 million people have died in the U.S. from COVID-19.

• What this means: COVID-19 vaccines can help prevent death from COVID-19. 

• Keep in mind: This data isn’t perfect. Booster shots were not included as a factor in this study, and partially vaccinated people were not accounted for as their own group.

To read more about this update, click or tap here. 

Moderna announces positive data for a low-dose version of their vaccine in young kids 

April 1, 2022

Two low-dose Moderna shots appear to create antibody levels in young kids that’s similar to young adults

Moderna recently announced that two low-dose shots of their vaccine led to a robust antibody response in kids ages 6 months to under 6 years old. In their interim data, immune response from the vaccine was thought to be comparable to adults ages 18 to 25.

The study also found that two doses of the low-dose Moderna vaccine were about 44% effective against new infections in kids ages 6 months to 2 years during the time when Omicron was predominant. They were also about 38% effective in kids ages 2 to under 6 years old. No kids in the study had severe COVID-19, went to the hospital, or died. 

This data comes from close to 7,000 kids who are enrolled in the study. A 25 mcg dose was used in this age group, whereas a 100 mcg dose is used in adults ages 18 and older. 

• What this means: The low-dose Moderna vaccine appears to have positive supporting data in young kids. Moderna researchers believe it provides similar benefits to their higher-dose vaccine that’s used in young adults.

• Keep in mind: Moderna is already working on getting their vaccine authorized for older kids and adolescents. Now, they’re also planning to request authorization in kids ages 6 months to under 6 years old. 

To read more about this update, click or tap here. 

CDC publishes more vaccine effectiveness data during Omicron’s predominance

April 1, 2022

New data is available about the J&J vaccine’s effectiveness during the Omicron wave

For the past few months, the CDC has preferred the mRNA COVID-19 vaccines (Pfizer and Moderna) over the J&J vaccine. Because of this, ongoing research into the J&J vaccine hasn’t been as highly prioritized. But the CDC recently released new effectiveness data for the J&J vaccine during the time of Omicron’s predominance. 

This data was collected between December 2021 and March 2022 in 10 U.S. states. Over 80,000 urgent care and emergency room visits — and over 25,000 hospitalizations — were analyzed.

• What this means: If you initially received the J&J vaccine, this data supports getting an mRNA vaccine for your booster dose. 

• Keep in mind: One J&J shot is considered to be the initial (primary) vaccine series. If you get a second shot, that’s considered to be the booster dose. 

To read more about this update, click or tap here. 

mRNA COVID-19 vaccines help lower the risk of mechanical ventilation or death by about 94%

COVID-19 vaccines remain highly effective against severe COVID-19 and its complications — even during the Omicron variant’s predominance. Recent CDC research shows that three doses of the Pfizer or Moderna vaccines help lower the risk of dying or going on a ventilator by about 94%. This is compared to unvaccinated adults. 

A ventilator, or mechanical ventilation machine, helps you breathe better. It’s used if you can’t breathe well enough on your own. 

• What this means: Getting fully vaccinated and boosted with a mRNA vaccine helps prevent some of the most severe complications of COVID-19.

• Keep in mind: This study was conducted before the FDA started recommending second booster shots for certain people. Added protection from a second booster shot isn’t included in these results.

To read more about this update, click or tap here. 

Pfizer vaccine can help prevent new Omicron infections in young kids

The Pfizer vaccine is currently authorized to be used by kids ages 5 and older. It’s also the only COVID-19 vaccine that’s currently authorized to be used by people younger than 18. But compared to older kids and adults, there still isn’t quite as much vaccine effectiveness data in younger kids. 

However, recent CDC data indicates that two doses of the Pfizer vaccine lowered the risk of new Omicron infections by 31% in kids ages 5 to 11. They also lowered the risk by about 59% in adolescents ages 12 to 15.

• What this means: In kids ages 5 to 15, two doses of the Pfizer vaccine can help lower the risk of catching Omicron by about 30% to 60%.  

• Keep in mind: COVID-19 vaccines — like the Pfizer vaccine — can help prevent new infections. But they’re more effective at preventing severe cases of COVID-19. 

To read more about this update, click or tap here. 

Two new CDC studies uncover data about vaccine effectiveness against urgent care visits, emergency room visits, and virus transmission from Omicron

March 2, 2022

Pfizer vaccine still helps protect against severe illness in children and adolescents

A new CDC study found that the Pfizer COVID-19 vaccine can help prevent severe illness caused by Omicron in children and adolescents, ages 5 to 17. But two to three doses of the Pfizer vaccine were effective to varying degrees. 

Among children, ages 5 to 11, two doses were about 51% effective against urgent care (UC) and emergency room (ER) visits within about 2 months of receiving a second dose. Among adolescents, ages 12 to 15, two doses were about 45% effective against UC and ER visits within about 5 months of receiving a second dose. 

Among teens, ages 16 and 17, two doses were about 34% effective against UC and ER visits within about 5 months of receiving a second dose. But after a booster shot was given, this effectiveness jumped up to around 81%. 

In the study, the vaccines were also very effective against hospitalization. However, the results didn’t differentiate between Delta and Omicron.

• What this means: Booster shots can help improve protection against severe illness caused by Omicron.

• Keep in mind: This study took place from April 2021 to January 2022, so it also includes data from before, during, and after Delta’s predominance. 

To read more about this study, click or tap here. 

COVID-19 vaccines shown to help lower the spread of Omicron within households 

Another recent CDC study found that people with a confirmed Omicron infection frequently spread the virus to other people in their household. Of 183 homes included in the study, t​​ransmission of the virus from someone with COVID-19 to someone without it occurred in 68% of households.

However, the study also found that people who tested positive but were previously vaccinated were less likely to spread the virus. About 43% of people who received a booster shot — and about 44% of people who were fully vaccinated no more than 5 months earlier — ended up with a household member who tested positive for COVID-19.

People in the study were also less likely to spread the virus to others if they took other preventive measures, such as isolating themselves from their household members and wearing a mask. 

• What this means: The Omicron variant is highly transmissible, and it’s important to take precautions when possible if you or a household member tests positive. 

• Keep in mind: It’s not too late to get vaccinated against COVID-19. They’re still a key source of protection against COVID-19. 

To read more about this data, click or tap here. 

Preprint New York study suggests that COVID-19 vaccines may be less effective against Omicron in children and adolescents

March 2, 2022

By the end of January, COVID-19 vaccines were about 12% effective against new infections in children ages 5 to 11

A New York study recently found that COVID-19 vaccine effectiveness went down between December 2021 and late January 2022 for children and adolescents. This is when Omicron was predominant. But the study is currently in preprint, meaning it hasn’t yet been peer-reviewed.

Over 1.2 million fully vaccinated kids, ages 5 to 17, were included in the study during this time. For children ages 5 to 11, vaccine effectiveness against new infections went down from about 68% to 12%. The vaccines remained slightly more effective for adolescents ages 12 to 17 — with effectiveness dropping from about 66% to 51%. 

But it’s important to keep in mind that children under age 12 receive a much lower vaccine dose compared to older groups. And, as mentioned above, booster shots are available for people ages 12 and older — they can help boost protection against Omicron.

Protection against severe illness was somewhat more consistent. By the end of January, vaccine effectiveness against hospitalization went down from about 100% to 48% for children ages 5 to 11. It went down from roughly 85% to 73% in adolescents ages 12 to 17. 

• What this means: Between December 2021 and January 2022, vaccine effectiveness against new infections went down for people ages 5 to 17. This was especially true for young children. But this study didn’t include boosters, which have been shown to provide added protection against Omicron.

• Keep in mind: COVID-19 vaccines have a key goal of protecting against severe illness, not necessarily new infections. Plus, boosters are recommended for everyone who are at least 12 years old and eligible.

To read more about this study, click or tap here. 

New CDC data suggests that giving COVID-19 vaccines to pregnant women can help protect newborns

February 22, 2022

Two Pfizer or Moderna shots are estimated to be about 61% effective against hospitalization in infants under 6 months old

Infants currently aren’t eligible to receive COVID-19 vaccines. But new CDC data suggests that women who were vaccinated during pregnancy can pass along antibodies that help protect their newborn baby.

This study found that two doses of the Pfizer or Moderna vaccine during pregnancy were about 61% effective at preventing hospitalization in infants under 6 months old. This effectiveness appeared to be higher when the vaccine series was completed later on in the pregnancy. 

Close to 380 infants were included in the study. It took place in the U.S. between July 2021 and January 2022, so it includes times when both the Delta and Omicron variants were predominant. 

• What this means: Getting vaccinated during pregnancy may help protect newborns from being hospitalized from COVID-19. 

• Keep in mind: The CDC recommends pregnant women to get vaccinated against COVID-19. They should also get booster shots when they’re eligible. 

To read more about these results, click or tap here. 

Clinical trial results suggest that Novavax’s COVID-19 vaccine may be an effective option for adolescents and adults

February 14, 2022

Novavax’s vaccine was about 80% effective at preventing COVID-19 in adolescents ages 12 to 17 when the Delta variant was predominant

Novavax recently announced study findings that show its COVID-19 vaccine was about 80% effective at preventing COVID-19 in adolescents ages 12 to 17 when Delta was the predominant variant in the U.S. 

This news comes after the vaccine was also found to be about 90% effective at preventing symptomatic COVID-19 in adults ages 18 and older. However, the adult portion of this study was conducted before Delta was predominant — people in the study received their doses between December 2020 and February 2021.

Novavax recently submitted a request to the FDA to authorize their vaccine for emergency use in adults. They also plan on applying for authorization in adolescents before the end of March 2022. 

• What this means: New data shows that Novavax’s COVID-19 vaccine candidate was highly effective at preventing COVID-19 in adolescents when the Delta variant was predominant.

• Keep in mind: Novavax’s vaccine is authorized for use in the U.K. and European Union, but it hasn’t been authorized yet by the FDA. 

To read more about this update, click or tap here. 

CDC publishes new data about the effectiveness of COVID-19 booster shots over time

February 14, 2022

Pfizer and Moderna vaccines are estimated to be about 78% effective against hospitalization after 4 months

The CDC recently published new data that offers more detail about the effectiveness of Pfizer and Moderna booster shots over time. 

In the study, the vaccines were about 87% effective at preventing urgent care and emergency room visits about 2 months after people received a booster shot. They were also about 91% effective against hospitalizations during this same time frame. This was while Omicron was predominant.

But after about 4 months, vaccine effectiveness started to wane. The vaccines were roughly 66% effective against urgent care and emergency room visits, and about 78% effective against hospitalizations. 

• What this means: Pfizer and Moderna vaccines continue to be important and effective prevention tools, but their effectiveness can slightly diminish over time. 

• Keep in mind: Booster shots are currently authorized and recommended for people ages 12 and older. Booster shots aren’t recommended yet for children ages 11 and younger.  

To read more about this study, click or tap here. 

CDC and UK studies provide additional COVID-19 vaccine effectiveness data from ongoing Omicron wave

February 2, 2022

Los Angeles-based study finds that fully vaccinated and boosted adults are 23 times less likely to be hospitalized than unvaccinated adults

New research published by the CDC shows that COVID-19 vaccines, with or without a booster shot, can help prevent COVID-19 infections and hospitalizations while the Omicron variant is predominant. 

More specifically, compared to unvaccinated adults, fully vaccinated adults in the study with a booster shot were roughly 4 times less likely to develop an infection. They were also about 23 times less likely to be hospitalized with severe COVID-19. 

Similarly, fully vaccinated adults without a booster shot were about 2 times less likely to develop an infection and about 5 times less likely to be hospitalized with severe COVID-19. 

This study used data from Los Angeles County, California, and it was conducted from November 2021 to January 2022. Over 420,000 people were included in the study. 

• What this means: COVID-19 vaccines help offer protection against new infections and hospitalizations during the time of Omicron’s predominance. 

• Keep in mind: Getting a booster shot — as recommended by the CDC — can help provide additional protection against infection and hospitalization from COVID-19. 

To read more about this update, click or tap here. 

UK study suggests that COVID-19 booster shots offer a ‘high level of protection’ from death related to Omicron

The U.K. Health Security Agency recently released findings that show COVID-19 vaccines, especially booster shots, help protect against death related to the Omicron variant in adults ages 50 and older.

In this population, initial COVID-19 vaccines were about 60% effective against death about 6 months after getting a second dose. But 2 weeks after getting a Pfizer or Moderna booster shot, this protection went up to over 90%.

This high level of protection appears to last over at least a number of weeks. Pfizer booster shots were found to be about 75% effective against hospitalization after about 14 weeks. Moderna booster shots were still over 90% effective against hospitalization after about 9 weeks. 

• What this means: Pfizer and Moderna booster shots can offer additional protection against hospitalization and death during the Omicron variant’s predominance. 

• Keep in mind: This is data from the U.K., not the U.S. However, these findings are still applicable for U.S. adults.

To read more about this update, click or tap here. 

New CDC data highlights booster shot effectiveness against the Delta and Omicron variants

January 26, 2022

Pfizer and Moderna COVID-19 booster shots are ‘highly effective’ against emergency room visits, urgent care visits, and hospitalizations 

A recent CDC study found that Pfizer and Moderna booster shots help protect against more severe cases of COVID-19 in adults. 

In this large study, booster shots were found to be about 82% effective at preventing emergency room and urgent care visits when the Omicron variant was predominant. During this time, they were also about 90% effective at preventing hospitalizations. Effectiveness was slightly higher in both situations when the Delta variant was predominant. 

This study was conducted in 10 U.S. states between August 2021 and January 2022.

• What this means: Pfizer and Moderna booster shots are highly effective at preventing more severe cases of COVID-19.

• Keep in mind: The J&J vaccine wasn’t evaluated in this study. At this time, the CDC prefers using the Pfizer and Moderna vaccines over the J&J vaccine in most cases. 

To read more about this study, click or tap here. 

COVID-19 vaccines, with or without booster shots, help protect against infections and death from COVID-19

Another recent CDC study found that COVID-19 vaccines help protect against infections and death from COVID-19. But specific effectiveness varies month-by-month. 

When Delta was predominant, unvaccinated adults were about 5 times more likely to test positive for COVID-19 than fully vaccinated adults. They were also about 16 times more likely to die from illness than fully vaccinated adults. 

By the end of November 2021, unvaccinated adults were almost 13 times more likely to die from COVID-19 than fully vaccinated adults. They were also about 53 times more likely to die than fully vaccinated adults who received a booster shot. 

But in early December 2021 — when Delta was still predominant but Omicron started to appear — unvaccinated adults were almost 3 times more likely to test positive than vaccinated adults. They were also almost 5 times more likely to test positive than vaccinated adults who received a booster shot. 

• What this means: In this study, COVID-19 vaccinations helped protect against illness and death caused by COVID-19. Booster shots added additional protection for those who received them.

• Keep in mind: This study stopped before Omicron — the current predominant variant in the U.S. — became widespread.

To read more about this study, click or tap here. 

More CDC data shows that unvaccinated adults are much more likely to be hospitalized from COVID-19 

CDC data from December 2021 shows that unvaccinated adults between the ages of 50 and 64 are 44 times more likely to be hospitalized from COVID-19 than fully vaccinated adults who received a booster shot. Unvaccinated adults ages 65 and older were also about 49 times more likely to be hospitalized. 

This same protection was high — but slightly lower — among fully vaccinated adults that didn’t receive a booster shot. In December 2021, unvaccinated adults ages 50 and older were 17 times more likely to be hospitalized than vaccinated adults. 

• What this means: Vaccinated adults, with or without a booster shot, were less likely to be hospitalized than unvaccinated adults in December 2021. 

• Keep in mind: This data reflects vaccine effectiveness during the time when Omicron became the prevalent variant. 

To read more about this data, click or tap here. 

CDC releases new data about Delta variant-related risks by vaccination status

January 21, 2022

COVID-19 vaccines and previous infections both boost protection against new infections, but vaccines also help prevent hospitalization

The CDC recently published study findings that show both COVID-19 vaccines and previous infections can help protect against the Delta variant. 

Before Delta became predominant in June, being vaccinated led to much better protection against new infections and hospitalization compared to unvaccinated people with a prior COVID-19 infection. But by early October 2021, prior infections led to higher levels of protection than vaccinations alone. 

By the end of the study, the highest levels of protection came from vaccinated people with a prior COVID-19 infection. Compared to vaccinated people, unvaccinated people who had a previous infection were hospitalized more frequently.

This information stems from California and New York-based data that was collected between May and November 2021. It doesn’t apply to infection and hospitalization risks posed by the Omicron variant or additional protection offered by booster shots. 

It’s also important to note that the study didn’t account for time since vaccination. This is important because the Delta surge happened as vaccine protection was waning.

• What this means: If you had a prior COVID-19 infection, getting vaccinated has been shown to provide additional protection against infection and hospitalization. This is compared to unvaccinated people with a prior infection alone.  

• Keep in mind: The best — and safest — way to prevent serious illness from COVID-19 is by getting vaccinated. The results from this study are not a reason to avoid getting vaccinated as recommended by the CDC. 

To read more about this update, click or tap here. 

Preliminary research from Israel suggests that a fourth COVID-19 shot is only partially effective against an Omicron infection 

January 21, 2022

A fourth shot raises protective antibody levels, but they don’t seem to be high enough to protect against Omicron infection

Early research from an Israeli hospital has found that a fourth COVID-19 shot can raise protective antibody levels against COVID-19. But it may not be enough to protect against an Omicron variant infection. 

The researchers haven’t released specific effectiveness numbers, but this study is still taking place. We’ll know more as time goes on, so stay tuned for more updates. 

• What this means: Fourth COVID-19 shots aren’t broadly authorized in the U.S. But health experts from around the world are looking into the possible need for additional booster shots going forward. 

• Keep in mind: These results haven’t been published — this is early data reported by multiple media outlets. 

To read more about this update, click or tap here. 

More data shows that the Pfizer COVID-19 vaccine provides high levels of protection against the Delta variant in adolescents

January 21, 2022

More evidence suggests that two doses of the Pfizer vaccine are ‘highly effective’ against hospitalization from the Delta variant

A recent New England Journal of Medicine study found that two doses of the Pfizer vaccine were “highly effective” in adolescents ages 12 to 18 at preventing hospitalization, ICU admissions, and the need for life support during the time when Delta was predominant in mid-to-late 2021.  

Specifically, two doses were about 94% effective against hospitalization in this age group. But the vaccine was found to be even more effective at preventing more severe COVID-19 — it was 98% effective at preventing ICU admissions and the need for life support. 

This data comes from a study of over 1,200 hospitalized U.S. adolescents ages 12 to 18. These hospitalizations happened between July and October 2021, which was before the Omicron variant was detected in the U.S. 

• What this means: The Pfizer vaccine provides high levels of protection against severe COVID-19 in adolescents. This was shown to be the case while the Delta variant was most prevalent.

• Keep in mind: This data only reflects adolescents as young as 12 years old, but the Pfizer vaccine is authorized in the U.S. for children ages 5 and older. 

To read more about this study, click or tap here.

Pfizer COVID-19 vaccine found to be highly protective against a severe inflammatory condition in teens 

January 11, 2022

Two doses of the Pfizer vaccine are about 91% effective against MIS-C

The CDC recently released study data that shows two doses of the Pfizer COVID-19 vaccine are about 91% effective against MIS-C. 

Multisystem inflammatory syndrome in children (MIS-C) is a health condition where inflammation affects many parts of a child’s body. MIS-C is a rare but serious response to a COVID-19 infection. It can develop weeks after an infection, even if a child had no symptoms or mild illness.    

This information comes from a study that took place between July and December 2021, when the Delta variant was predominant. About 100 hospitalized U.S. adolescents ages 12 to 18 were included in the study. 

Of these adolescents, only five were considered fully vaccinated before going to the hospital. No vaccinated people in the study needed life support due to MIS-C, and only one was sent to an intensive care unit (ICU). 

And even though this study only included adolescents ages 12 to 18, the CDC predicts that this protection likely applies to children as young as 5 years old. 

• What this means: Two doses of the Pfizer vaccine appear to provide high levels of protection against MIS-C. 

• Keep in mind: This study occurred when Delta was predominant. These results don’t directly apply to Omicron. 

To read more about this study, click or tap here. 

Multiple studies provide preliminary information about COVID-19 vaccine effectiveness against the Omicron variant 

January 6, 2022

Pfizer booster shot effectiveness may wane after about 2 to 3 months, but a Moderna booster appears to last longer

Recent U.K. data shows that after two initial Pfizer shots, a Moderna booster may provide better protection over time against Omicron than a Pfizer booster. 

A study looked at nearly 70,000 Omicron cases in the U.K. in late 2021. It found that a Pfizer booster shot provided about 70% protection against Omicron-related illness soon after receiving the shot. But this protection went down to 45% or less after 10 weeks (2.5 months). By comparison, a Moderna booster shot still provided up to 75% protection after about 9 weeks. 

However, this study didn’t look at the effects of a Moderna booster shot after two initial Moderna shots. It also didn’t consider the J&J vaccine. 

• What this means: U.K. data suggests that protection from a Pfizer booster shot may start to go down after about 2 months. 

• Keep in mind: We are still learning about the effects of COVID-19 booster shots over time, so this data should be taken with a grain of salt. 

To read more about this data, click or tap here. 

Large South African study finds two doses of the Pfizer vaccine to be 70% effective against hospitalization from Omicron   

Even though booster shots are now available in countries like the U.S., many areas of the globe are still focusing on initial vaccine shots. 

In a study that looked at over 130,000 PCR test results, South African health experts found that two doses of the Pfizer vaccine were about 70% effective against hospitalization from Omicron. But during the time when Delta was the predominant variant in South Africa, two shots were about 93% effective against hospitalization. 

• What this means: The Pfizer vaccine appears to be slightly less effective against Omicron than Delta, but it still provides protection against severe illness. 

• Keep in mind: This study only looked at the Pfizer vaccine, not the Moderna or J&J vaccines. 

To read more about this study, click or tap here. 

J&J booster shot estimated to be 85% effective against hospitalization from Omicron

A recent Johnson & Johnson press release said that two doses of their vaccine are 85% effective against Omicron-related hospitalization. Since the J&J vaccine is a one-shot vaccine, the second dose is the booster shot. 

This information comes from a study conducted in South Africa after Omicron became the dominant variant. Healthcare workers, not the general public, were studied. 

And in a different study, J&J found that a “mix-and-match” approach using their vaccine as a booster could be beneficial. Among people who received the Pfizer vaccine series initially, a J&J booster shot improved protective antibody levels by 41 times compared to people who received a Pfizer booster (17 times). 

• What this means: The J&J vaccine is still a viable tool to help protect against the rapidly spreading Omicron variant. 

• Keep in mind: The J&J vaccine is authorized in the U.S., but the CDC prefers the Pfizer or Moderna vaccines when feasible. 

To read more about this announcement, click or tap here. 

Israeli study suggests fourth Pfizer vaccine boosts protective antibody levels

Israeli researchers are already studying the effects of a fourth Pfizer shot. This week, an Israeli government official announced early study results that showed a fourth Pfizer shot raises protective antibodies against Omicron “five-fold” after about a week of getting the extra shot. 

This study looked at these effects in 150 healthcare workers. But as a country, Israel is giving fourth COVID-19 shots to adults over 60, healthcare workers, and people with weak immune systems. This is just early data, but it shows that health experts are evaluating the possibility of needing another jab at some point in the future. 

• What this means: Early data from Israel shows that a fourth Pfizer shot has potential benefits, but we still need more data. 

• Keep in mind: You should not get a fourth shot if you already received a booster shot. This is preliminary study data, not a CDC- or FDA-backed recommendation. 

To read more about these findings, click or tap here. 

Early laboratory tests suggest that Pfizer and Moderna vaccines may provide protection against the Omicron variant

December 20, 2021

Moderna says their booster shot raises the amount of Omicron-fighting antibodies by about 37x

Today, Moderna reported preliminary lab data that suggests their COVID-19 vaccine can protect against the Omicron variant. Specifically, they found that a Moderna booster shot improved the amount of neutralizing antibodies against Omicron by about 37 times almost 30 days after the booster shot. 

The Moderna booster shot is half the dose (50 mcg) of the first two shots (100 mcg). The company also studied the effects of a 100 mcg booster shot against Omicron, but it said the lower dose provides adequate protection against the new variant. 

And while laboratory data is a good predictor of protection, it’s not the same thing as studying the vaccine’s effects in people directly. It’s expected that Moderna will continue evaluating their vaccine against Omicron, and they’re also planning on making an Omicron-specific vaccine in 2022. 

• What this means: Early data suggests that a Moderna booster shot can help protect against the Omicron variant. 

• Keep in mind: These are early lab tests. The vaccine will continue to be studied as we learn more about Omicron.

To read more about this study, click or tap here. 

Pfizer vaccine found to provide 33% protection against new Omicron infections, 70% protection against hospitalization

A new study conducted by Discovery Health — a South African health insurance company — suggests that the two doses of the Pfizer COVID-19 vaccine may provide less protection against Omicron than previous variants. 

This study looked at over 78,000 positive COVID-19 cases between November 15, 2021 and December 7, 2021. During this 3-week period, the Pfizer vaccine was found to be 70% effective against hospitalizations during an Omicron surge. But it was found to be 33% effective against new infections. 

This research provides some helpful insight, but it’s also preliminary. As time goes on, we’ll learn more about how effective COVID-19 vaccines are against this new variant. 

• What this means: The Pfizer vaccine appears to provide less protection against new infections from the Omicron variant. But it still provides good protection against hospitalizations. 

• Keep in mind: This is early data. We’ll know more as we continue to learn about the variant.

To read more about this study, click or tap here. 

Two doses of Pfizer’s vaccine doesn’t provide expected protection in children ages 2 through 4

December 20, 2021

Pfizer is now looking to see if a third shot will boost immunity in this age group

Pfizer recently reported that its low-dose (3 mcg) COVID-19 vaccine didn’t lead to an adequate immune response in children ages 2 through 4. However, children from 6 months to 2 years old did have an adequate response.

With these results, the company is planning on seeing if a third dose will lead to better protection in this age group. Children as young as 6 months old will also be included in this study.

These efforts are part of Pfizer’s ongoing goal to have its vaccine approved for young children. Pfizer’s vaccine is currently approved for people ages 16 and older. It’s also authorized for children ages 5 to 15. 

• What this means: Pfizer has found that two doses of their COVID-19 vaccine don’t trigger an adequate immune response in children ages 2 through 4 years old.

• Keep in mind: This is a developing story. Pfizer is still studying their vaccine in this age group. 

To read more about this update, click or tap here. 

CDC updates COVID-19 vaccine recommendations

December 20, 2021

Pfizer and Moderna vaccines now recommended over the J&J vaccine

The CDC has updated its COVID-19 vaccine recommendations. The agency now recommends that you should consider getting an mRNA (Pfizer or Moderna) COVID-19 vaccine over a J&J vaccine if both options are available in your area. 

This updated recommendation came shortly after one of the CDC’s expert committees had an in-depth discussion about the J&J vaccine’s safety and effectiveness. 

One of the key factors that played into this decision was the J&J vaccine’s rare, but serious, risk of life-threatening blood clots in some people. The committee also found that it prevents hospitalizations and death from COVID-19 less effectively than the Pfizer and Moderna vaccines. 

But if you prefer (or need) the J&J vaccine instead of a Pfizer or Moderna vaccine, it’s still available in the U.S. The benefits of the J&J vaccine also outweigh the risks of being unvaccinated.

• What this means: The CDC now prefers the Pfizer and Moderna vaccines over the J&J vaccine when possible. 

• Keep in mind: The J&J vaccine is still available in the U.S., and you can still receive it if you need or want it. 

To read more about this update, click or tap here. 

Israeli study reports that three Pfizer COVID-19 shots may help protect against the Omicron variant

December 13, 2021

A third Pfizer shot seems to neutralize the Omicron variant; two doses may not be enough

A small laboratory study from Israel reported that three doses of the Pfizer COVID-19 vaccine can neutralize (target and fight) the Omicron variant. 

And while this is encouraging news, Israeli researchers also suggested a Pfizer booster provides more protection against the Delta variant than it does Omicron. It also found that only two doses of the Pfizer vaccine given 5 to 6 months prior don’t neutralize the Omicron variant effectively. 

In this study, 40 people were split into two equal groups. One group of healthcare workers received a booster shot about 1 month before the study started. A second group received their second Pfizer dose about 6 months prior but didn’t receive a booster. Researchers then analyzed their blood samples. 

This research hasn’t been published yet, but it’s expected to be published after experts review the data. Specific effectiveness numbers also haven’t been released in any press announcements. 

• What this means: This data suggests that a Pfizer COVID-19 booster shot can help protect against the Omicron variant. 

• Keep in mind: Information about vaccine effectiveness against Omicron is still being researched. Stay tuned for more information, especially as data from larger studies becomes available. 

To read more about this study, click or tap here. 

Preliminary findings suggest Pfizer COVID-19 booster shots may protect against the Omicron variant

December 8, 2021

Laboratory study suggests that three Pfizer shots neutralizes the new variant  

In late November, the World Health Organization (WHO) announced the Omicron variant is a variant of concern. Today, Pfizer announced preliminary findings from a laboratory study testing their COVID-19 vaccine against this new variant. 

The initial findings suggest that three doses of their vaccine helps create enough antibodies to neutralize (target and fight) the Omicron variant. This is thought to lead to protection that’s similar to two doses that have been effective against other variants. 

In the same press release, Pfizer said that two doses of their vaccine may still protect against severe COVID-19. But compared to previous variants, two doses may provide less protection against new infections. 

But, importantly, these results are from an early laboratory study. Since the Omicron variant was only recently identified, there hasn’t been enough time to directly study the vaccine’s effectiveness in people. More effectiveness data will likely be announced as more becomes known about this variant. 

• What this means: A Pfizer booster shot may help protect against illness caused by the Omicron variant. Aside from these findings, booster shots are currently recommended for all adults based on when their initial vaccine series was completed.

• Keep in mind: This information is not widely generalizable. These are early laboratory findings that look at the difference in antibodies from two or three shots against the Omicron variant. 

To read more about this update, click or tap here. 

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Written by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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The best way to protect yourself and those around you from serious illness is to get vaccinated against COVID-19. The Pfizer, Moderna, and Novavax vaccines are all approved or authorized for use in the U.S. — and they’re all considered to be safe and effective. 

Check back with GoodRx for the latest news on COVID-19 vaccine approvals, safety, efficacy, and more.