RSV Prevention in Children: Your GoodRx Guide to Abrysvo vs. Beyfortus

Babies are particularly vulnerable to severe illness from respiratory syncytial virus (RSV) infection, so providing protection is important. There are two ways to do this: you can receive Abrysvo, an RSV vaccine, during pregnancy, or your baby can receive Beyfortus (nirsevimab-alip), a monoclonal antibody injection, after they’re born.

Abrysvo and Beyfortus typically aren’t used together, with a few exceptions. But when comparing Abrysvo versus Beyfortus, is one more effective than the other? And what are the risks? Let’s compare Abrysvo versus Beyfortus. 

1. Abrysvo is a vaccine, while Beyfortus is a monoclonal antibody

One major difference between Abrysvo versus Beyfortus is that Abrysvo is a vaccine, and Beyfortus is a monoclonal antibody medication. A vaccine trains your immune system to fight an infection by helping it build long-term protection against a threat, such as a virus or bacteria. A monoclonal antibody medication provides your body with ready-made antibodies without teaching your body to create its own.

How Abrysvo works

There are many types of vaccines. But all vaccines prepare your body to respond to an infection should you encounter it in the future. Abrysvo is a subunit vaccine, meaning it contains a piece of a germ (RSV, in this case) which trains your body to identify true RSV if you encounter it.

Abrysvo contains a specific form of a protein called prefusion (preF). This protein is what allows RSV to infect healthy cells. When your body receives preF proteins from Abrysvo, it responds by making antibodies against preF. An antibody is a protein made by your immune system that helps your body fight off infections.

These antibodies transfer from you to your baby during pregnancy. Having antibodies against the preF protein helps your baby’s immune system identify and attack RSV if they become exposed to it.

How Beyfortus works

Beyfortus is an injectable monoclonal antibody medication. It contains RSV antibodies against the preF protein. So while receiving Abrysvo causes your body to create antibodies, Beyfortus contains the antibodies in this formulation. So when your baby receives Beyfortus, it receives these antibodies directly.

If your baby encounters RSV, these antibodies bind to the preF protein. This prevents RSV from entering and infecting cells in the body.

2. Abrysvo is administered to pregnant mothers and Beyfortus is given to infants

Both Abrysvo and Beyfortus protect infants against severe RSV. But Abrysvo is administered to pregnant mothers. Beyfortus, on the other hand, is given directly to infants and young children.

EXPERT PICKS: WHAT TO READ NEXT

• A guide to childhood RSV: Here’s what you need to know about RSV in kids.

• All about Beyfortus: Learn how it works, who should get it, and more.

• Abrysvo side effects: Learn more about this RSV vaccine’s side effects and how to manage them.

Who should receive Abrysvo?

Abrysvo is FDA approved as a single dose for pregnant mothers at 32 to 36 weeks of pregnancy. 

The CDC only recommends receiving Abrysvo between September to January. This is because September is typically about 1 to 2 months before the start of RSV season, and January is typically a couple months before the RSV season ends.

Receiving Abrysvo outside of these months isn’t considered helpful to your baby, unless you live in an area where the RSV season is less predictable, such as Alaska and tropical climates like southern Florida and Hawaii.

Who should receive Beyfortus?

Beyfortus is FDA approved for infants born during, or entering, their first RSV season. It’s also approved for children up to 24 months of age (2 years old) in their second RSV season who are at risk of severe RSV. 

However, the CDC recommendations for Beyfortus use are different from its FDA approved indication. CDC recommendations for Beyfortus apply to a slightly smaller group of children. This includes: 

• Infants under 8 months old going into their first RSV season only if the mother didn’t receive Abrysvo during pregnancy, or if the baby was born within 14 days of Abrysvo being given.

• Children between 8 to 19 months old who are entering their second RSV season and are at high risk of severe RSV. This includes children who are severely immunocompromised, have a low body weight, or have cystic fibrosis with severe lung disease. American Indian and Alaska Native children are also at greater risk of severe RSV.

Pediatricians typically follow CDC recommendations when deciding whether to recommend Beyfortus.

3. It takes 2 weeks for antibodies to pass to your baby after receiving Abrysvo, but Beyfortus works immediately

It takes at least 2 weeks after receiving Abrysvo for antibodies to pass from mother to baby. But recently, a small study showed that receiving Abrysvo closer to 32 weeks may be most effective. The researchers found that being vaccinated at least 5 weeks before delivery allows more antibodies to be transferred from mother to baby. Beyfortus begins to work immediately after your baby receives it, passing antibodies to the child who received it right away.

If you deliver your baby within 2 weeks of receiving Abrysvo, your baby won’t receive enough antibodies to be well-protected from severe RSV infection. In many cases, their pediatrician will also recommend that they receive Beyfortus soon after birth.

4. Abrysvo and Beyfortus are administered differently

When administered to a pregnant mother, Abrysvo is given as a single dose between weeks 32 to 36 of pregnancy. It’s an intramuscular (IM) injection that’s administered by a healthcare professional, often in the upper arm. Administering Abrysvo during this timeframe offers maximum protection to the infant after it’s born, while managing potential risks. Protection is expected to last 6 months.

Beyfortus is also given as a single dose during the RSV season. This is because research indicates that protection from Beyfortus lasts at least 5 months, so one dose should last an entire RSV season. It’s also an IM injection. It’s injected by a healthcare professional, typically into the thigh muscle.

5. Abrysvo and Beyfortus have different side effects

Both Abrysvo and Beyfortus are considered safe when used as recommended. But like most medications and vaccines, they have some side effects and risks to consider.

Keep in mind that the Abrysvo and Beyfortus don’t make you (or your baby) sick with RSV, which is a common misconception. But you or your baby can feel a little under the weather in the day or so that follows, due to side effects of the product itself. If you experience side effects, you can report them to the FDA and CDC. Abrysvo side effects can be reported to the Vaccine Adverse Event Reporting System (VAERS) program and Beyfortus side effects can be reported to the MedWatch program. 

If any side effects feel severe or life-threatening, seek medical attention right away. This includes a severe allergic reaction (like anaphylaxis). If you or your child has hives, shortness of breath, or a blue skin color after receiving Beyfortus or Abrysvo, seek immediate medical care.

Abrysvo side effects

Pregnant women receiving Abrsyvo may experience:

• Nausea

• Injection site reactions like pain and redness at the injection site

• Muscle pain

• Headache

Serious side effects like Guillain-Barré syndrome have been reported, but this is rare. Additionally, some research shows that pregnant mothers receiving Abrysvo have had more instances of preeclampsia or preterm births compared to those who didn’t receive the vaccine. However, other research hasn’t found this to be true.

We can’t say for sure if Abrysvo increases your risk of preeclampsia or preterm birth. And these vaccines are considered safe for most pregnant women. But if you’re at higher risk for preeclampsia or preterm birth already, talk to your OB-GYN. They can help you decide whether Abrysvo or Beyfortus is a better option to protect your baby.

Beyfortus side effects

Side effects with Beyfortus are unlikely. The most common side effect is a rash, but was reported in less than 1% of children during clinical trials.

Additionally, injection site reactions like pain and redness can also happen. But these reactions aren’t common. If they do occur, they can often be managed at home.

So, is Beyfortus or Abrysvo more effective?

At this time, there aren’t head-to-head studies comparing Abrysvo versus Beyfortus. So we can’t say for sure if one is more effective than another. But we can look at the research on each product individually. 

In a study of about 3,000 pregnant women, Abrysvo lowered the risk of severe RSV in newborns by about 91% within the 3 months after birth, and 77% within 180 days after birth. This data applies to pregnant mothers who received the vaccine from weeks 32 to 36 of pregnancy.

In pooled evidence from clinical trials, including over 2,300 infants, Beyfortus was about 80% effective at preventing hospitalization for RSV requiring medical care in babies under 8 months old during their first RSV season. And real-world evidence shows even better results — Beyfortus is about 90% effective at preventing hospitalization for RSV during a baby’s first RSV season.

So, Beyfortus and Abrysvo are both effective. Which one is best for your baby depends on other factors, including your preference for maternal vaccination versus infant injections.

Good to know: Even if you receive Abrysvo, or your child receives Beyfortus, it’s still possible for your child to get RSV. But they’ll be less likely to become seriously ill or require hospitalization.

Should a baby receive Beyfortus if their mother received Abrysvo?

No, not at this time. The CDC and the American College of Obstetricians and Gynecologists don’t recommend that an infant receive Beyfortus if their mother was vaccinated with Abrysvo during pregnancy.

However, there are some exceptions to this, including:

• You had your baby within 14 days of receiving Abrysvo. It takes at least 2 weeks for an adequate amount of antibodies to transfer from the mother to baby after receiving Abrysvo. So if you have your baby within 14 days of receiving Abrysvo, your baby may need Beyfortus.

• The child is eligible to receive Beyfortus during their second RSV season. If your child meets criteria for receiving Beyfortus during a second RSV season, they may receive the injection even if their mother received Abrysvo while pregnant. In this case, Abrysvo only protected the child during their first RSV season.

• It’s unknown whether the mother received Abrysvo during pregnancy. If you don’t know whether you received Abrysvo during pregnancy, and the information can’t be verified, your child may qualify for Beyfortus.

• If your baby may have lost antibodies gained from Abrysvo. Some infants, such as those who have certain cardiac surgeries, may lose antibodies and may benefit from receiving Beyfortus, even if you received Abrysvo during pregnancy.

• The baby is at very high risk of severe RSV. Their pediatrician may decide that vaccinating with Beyfortus is a good idea to provide maximal protection to the baby.

• The mother receiving Abrysvo may not have an adequate response to the vaccine. If the pregnant mother is immunocompromised, they may not make enough to pass to their baby as expected. In this case, your baby may qualify for Beyfortus.

Can a pregnant mother receive Abrysvo during more than 1 pregnancy?

No, at this time, Abrysvo isn’t recommended during more than one pregnancy. If you received Abrysvo during one pregnancy, you shouldn’t receive it again, even during future pregnancies. In this case, babies born from subsequent pregnancies should receive Beyfortus.

So, what’s the verdict? Is Abrysvo or Beyfortus a better option?

For now, there’s no definitive answer to this question. So when deciding between Abrysvo and Beyfortus, the choice depends on your individual situation and preferences.

For example, you may choose Abrysvo if you prefer maternal vaccination versus your baby receiving an injection after birth. You may also choose Abrysvo if your hospital or pediatrician’s office doesn’t offer Beyfortus (or vice versa, you may choose Beyfortus if they don’t offer Abrysvo).

On the other hand, Beyfortus is a better option for your baby if you’ve received Abrysvo during a previous pregnancy. It’s also a good option if you don’t wish to receive a vaccine during pregnancy. And, if you’re past 36 weeks pregnant and you haven’t received Abrysvo yet, Beyfortus is a better option for your baby.

Consult your pediatrician to ask for their recommendation on RSV prevention for your baby. They can help you weigh the pros and cons of both Beyfortus and Abrysvo. Below, we’ll summarize some of the major differences.

How to save

Beyfortus’ list price is about $500. But Beyfortus is typically covered by private insurance plans. This is a requirement of the Affordable Care Act. Still, it’s a good idea to call your insurance company directly to ask whether Beyfortus is covered for your child.

If your child is eligible for Medicaid, or is uninsured or underinsured, or American Indian or Alaska Native, they may qualify to receive Beyfortus for free through the VFC program. This program provides certain vaccines and immunizations for free to children who meet certain criteria. To find a VFC provider, go to your state’s VFC provider locator.

Additionally, most insurance plans cover Abrysvo, including Medicaid. If you don’t have insurance, or you’re underinsured, Pfizer (the manufacturer of Abrysvo) has a patient assistance program that may help you access Abrysvo for free. Additionally, Abrysvo’s cost with a free GoodRx discount may be about $311.57.

Why trust our experts?

Written by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

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.

Reviewed by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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