Abrysvo vs. Arexvy: 6 Ways These RSV Vaccines Compare and How to Choose

After unsuccessful attempts to develop a safe and effective respiratory syncytial virus (RSV) vaccine in years prior, the FDA approved the first two RSV vaccines in 2023 — Arexvy and Abrysvo. The first RSV vaccine, Arexvy, was approved in May 2023. Abrysvo’s approval followed a few weeks later.

For most adults, RSV causes a mild cold-like illness. But some people, especially older adults, have a higher risk of serious illness. Babies are also particularly vulnerable to severe RSV. This is where RSV vaccines can provide an added layer of protection for those at higher risk.

So, how do you decide between Arexvy and Abrysvo? Here’s what you should know. 

Arexvy vs. Abrysvo overview

Arexvy and Abrysvo have several similarities, but there are a few differences. Here is a comparison of Arexvy versus Abrysvo and their key features:

Below, we’ll discuss six ways they compare.

1. Arexvy and Abrysvo are approved for adults age 18 and older

Abrysvo and Arexvy are both FDA approved to lower the risk of respiratory illness from RSV among adults ages 60 and older. Additionally, both Abrysvo and Arexvy are approved for people ages 18 to 59 who are at increased risk of severe RSV. Abrysvo was approved for this younger group in October 2024, followed by Arexvy in March 2026.

The most recent CDC RSV vaccine recommendations apply to all adults ages 75 and older, as well as certain people ages 50 and older who are at a higher risk.

So, why is it important for older adults to get vaccinated against RSV? As mentioned above, older adults have a higher risk of severe RSV, which can lead to pneumonia and make existing health conditions worse. This is because your immune system doesn’t work as well as you get older. In fact, it’s estimated that up to 160,000 older adults require hospitalization from RSV each year.

A recent CDC study found that the RSV vaccines were about 58% effective against hospitalization from RSV in older adults after two seasons. Both Abrysvo and Arexvy were included in this study.

Good to know: The first season of the CDC study on RSV vaccines showed about 69% effectiveness, then effectiveness dropped to 48% after the second season. More studies are needed, but it’s possible the CDC may recommend a booster shot in the future.

2. Abrysvo is also approved for use during pregnancy to protect newborns after birth

In addition to older adults, babies are also at a higher risk of severe RSV. In this case, pregnant women can get an RSV vaccine during pregnancy to protect their babies after birth.

Similar to other vaccines given during pregnancy, babies can be protected for a period of time after they’re born through passive immunity. This happens when antibodies (immune memory cells) from the mother pass to the fetus through the placenta during pregnancy.

In August 2023, the FDA approved a one-time shot of Abrysvo for women during weeks 32 to 36 of pregnancy. When given during this time, the vaccine can prevent respiratory illness from RSV through at least 6 months after the baby is born.

Abrysvo was studied in about 3,500 pregnant women. Compared to placebo (an injection without the vaccine), Abrysvo lowered the risk of respiratory illness from RSV in newborns by about 82% within 3 months after birth. And when the vaccine was given between weeks 32 and 36 of pregnancy, this risk was cut by about 91%.

Of note, there was a slightly higher percentage of preterm births in women who received Abrysvo compared to the placebo group during clinical trials. But it’s not clear if this was due to the vaccine or another cause.

3. Both Abrysvo and Arexvy can protect against serious respiratory illness from RSV

RSV can cause lower respiratory tract disease (LRTD) that can lead to life-threatening lung problems, including pneumonia. RSV vaccines can help lower the risk of LRTD from an RSV infection.

According to a systematic review, the results from multiple studies showed that Arexvy lowered hospitalizations from RSV among older adults by 60% to 65%. And Abrysvo lowered hospitalizations among older adults by 58% to 63%.

Studies are ongoing to collect additional data on how well the vaccines work and how long protection lasts. However, clinical trial data has shown protection lasting through 23 months from Arexvy and through 16 months with Abrysvo.

4. Abrysvo and Arexvy both work in a similar way

Abrysvo and Arexvy are not live vaccines, meaning that they don’t contain a weakened form of RSV. Instead, they’re both recombinant subunit vaccines. This means they contain pieces of virus that are used to stimulate the immune system. In this case, the RSV vaccines contain a specific form of a protein (called prefusion or preF) that normally helps the virus attach to healthy cells and infect them.

When your immune cells detect the preF proteins from the vaccine, your body makes antibodies against them. This helps your immune system quickly identify and attack RSV if you’re exposed to it in the future. You can still get RSV, but there’s a lower chance that you’ll get seriously sick.

Keep in mind: A third RSV vaccine from Moderna, called mRESVIA, is also available. It’s a different type of vaccine than Abrysvo and Arexvy. It’s a messenger RNA (mRNA) vaccine, which uses similar technology as the Moderna COVID-19 vaccine.

5. Abrysvo and Arexvy contain different ingredients

Abrysvo and Arexvy are the same type of vaccine (recombinant subunit vaccine). But they’re made up of different ingredients.

Abrysvo is considered a bivalent vaccine. It contains preF proteins from two RSV subtypes: RSV A and RSV B. Arexvy also contains preF proteins, but it isn’t considered a bivalent vaccine. Even so, it has also been shown to protect against RSV A and RSV B.

Another difference between the RSV vaccines is that Arexvy contains an adjuvant. Adjuvants are substances that are sometimes added to vaccines to help them work better. Abrysvo does not contain an adjuvant.

Abrysvo and Arexvy are both free of preservatives. However, they do contain additional ingredients that help with stability and acidity of the vaccine. These ingredients are listed in the table below.

If you’re allergic to any RSV vaccine ingredients, you shouldn’t receive that vaccine. Talk to a healthcare professional if you have questions about which vaccine is safe for you.

6. Abrysvo and Arexvy can cause similar side effects

During clinical trials, people receiving Abrysvo or Arexvy reported similar side effects. The most common RSV vaccine side effects for older adults included:

• Pain at the injection site

• Feeling tired

• Muscle pain

• Headache

In addition to the side effects listed above, pregnant women receiving Abrsyvo also reported nausea. And while rare, some people reported serious side effects such as Guillain-Barré syndrome. Keep in mind that these aren’t all possible side effects from the vaccines.

You can’t get sick with RSV from either RSV vaccine, but you can feel lousy for a few days afterwards. If you experience any side effects after getting your shot, you can report it to the FDA and CDC. This helps them track vaccine safety on an ongoing basis. But if any side effects feel severe or life-threatening, get medical attention right away.

Who is eligible to receive an RSV vaccine?

The CDC currently recommends that adults ages 75 and older receive one dose of an RSV vaccine. People who are 50 to 74 years old and at an increased risk of severe RSV are also eligible. As of right now, the RSV vaccine is given as a one-time dose. In other words, you don’t need to get the RSV vaccine again if you already received it.

The CDC also recommends a single dose of Abrysvo, given September through January, for women who are between 32 and 36 weeks of pregnancy. If you’ve recently given birth, medications are available to help protect newborns and infants entering their first RSV season from severe illness. Talk to your healthcare team about your options and eligibility for RSV prevention. If you’ve received Abrysvo during a prior pregnancy, it’s not currently recommended to receive it again during subsequent pregnancies.

How do you choose which RSV vaccine is right for you?

When deciding which RSV vaccine is right for you, there may be certain factors to consider. For example, Abrysvo and Arexvy contain different ingredients. This may be important if you have allergies. Otherwise, either vaccine should suffice for older adults. Abrysvo is the only option for pregnant women.

While both vaccines are approved, certain locations may carry one or the other. And it may not be clear which one is in stock. If you’re looking for a specific RSV vaccine, it may be worth calling ahead to your pharmacy or clinic if the information isn’t available online.

Frequently asked questions

Why trust our experts?

Written by:

Kristianne Hannemann, PharmD

Kristianne Hannemann, PharmD, is a licensed pharmacist in California. She has been a retail pharmacy manager and staff pharmacist for over 7 years and has contributed drug information content to different health companies.

Edited by:

Sheila McAdoo, PharmD

Sheila McAdoo, PharmD, is a licensed pharmacist in Virginia and New York. She has worked in the pharmacy industry for 14 years.

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.

Our editorial standards

Meet our experts