

Summary:
Beyfortus® has been shown to have a consistent safety profile. In clinical trials, patients taking Beyfortus had similar experiences to those taking a placebo—this means that babies who received Beyfortus had about the same side‑effects as babies who didn’t receive it. Beyfortus is unlikely to react with other medications. The most common side effects include mild rash and pain, swelling or hardness at the injection site. Serious allergic reactions have happened. If more serious side effects occur, talk to your baby's doctor right away.
Beyfortus is a preventive antibody for RSV, not a vaccine

Beyfortus is the #1 prescribed RSV protection for babies.*
*IQVIA data through March 2025.

More than 11 million babies worldwide have been immunized with Beyfortus since its approval.†
Across these millions of doses, Beyfortus helps provide protection to babies throughout the typical RSV season.1
†11 million is estimated based on sales data (through Oct 2024).

Preventive antibodies, similar to Beyfortus, have been given to babies for over 25 years.

Preventive antibodies act like a bodyguard for your baby’s immune system, offering ready-made protection against serious RSV.
Unlike vaccines, which train the body to respond over time, Beyfortus helps provide fast-acting defense against serious RSV lung infection—no training required.
Possible Beyfortus side effects
View the Patient Information Sheet for a downloadable version of Beyfortus safety information.1
Most common side effects
In clinical trials, Beyfortus was shown to be well tolerated by babies, with the vast majority of reported side effects being mild and temporary. According to the clinical data, the most common side effects include1:
- Mild rash
- Pain, swelling, or hardness at your baby's injection site
Potential serious adverse reactions
While uncommon, serious allergic reactions have happened with Beyfortus.
Get medical help right away if your child has any of the following signs or symptoms of a serious allergic reaction1:
- Swelling of the face, mouth, or tongue
- Difficulty swallowing or breathing
- Unresponsiveness
- Bluish color of the skin, lips, or under fingernails
- Sudden muscle weakness
- Severe rash, hives, or itching
If your child has a condition that effects their blood clotting and causes bleeding or bruising problems, extra care should be taken with injections.
Before your child receives Beyfortus, tell your doctor about all of your child’s medical conditions.
Moms and babies’ experiences with Beyfortus®
“I hope that by sharing my story, I can encourage others to research Beyfortus to see if it would be a good fit for their little one.”
Clementine, Mom of Nolan and Liam
Read about Clementine’s RSV experience
Clementine’s video transcript
CLEMENTINE: I am being compensated for sharing my story with you in this video.
I love everything that has to do with family. Spending time with my family is, I feel like that’s my purpose.
The first time I found out I was going to be a mom, I was excited. I was overjoyed.
A bit overwhelming because we, we don't have a lot of family around. Most of our family is in Ghana, West Africa.
I knew about RSV because of my health training, and when Nolan was exhibiting…
… labored breathing, I knew it was time to take him to the ER. Even as a healthcare provider…
…and seeing lots of kids who are not well, when it’s your own kid, you freak out. That moment, you’re not a nurse. You’re a mom. You’re a parent.
And all you want to do is make sure that your baby is fine.
That moment was very scary. To see your child who seemed so helpless and was having trouble breathing, and you can’t do anything about it.
We learned about Beyfortus at Liam’s pediatrician appointment. This was two days after he was born.
Our baby’s doctor told us that there was a way to help prevent serious RSV lung infection.
When he said Beyfortus would be a good idea for Liam…
…of course we said yes because we did not want what happened with Nolan…
… to repeat with Liam.
He shared that the most common side effects include rash and pain, swelling or hardness at the site of your child’s injection.
Your child should not take Beyfortus if your child has a history of serious allergic reactions to nirsevimab-alip or any of the ingredients in Beyfortus.
We had been through a rough experience and wanted to take whatever preventive measures that were available.
We are very glad Liam received Beyfortus. Thankfully, he has not had any symptoms yet of cold or RSV.
Nolan always brings home germs of everything, so I’m glad Beyfortus is on board to help prevent RSV serious lung infection…
…from happening to our second baby.
It’s important for me to tell my story because I’m a nurse practitioner, but I’m also a Black woman from Ghana. I understand why there’s an uncertainty in trusting healthcare providers.
And I hope sharing my story will give others the initiative…
…to research Beyfortus to see if it would be a good fit for their little one.
IMPORTANT SAFETY INFORMATION
Your child should not take Beyfortus if your child has a history of serious allergic reactions to nirsevimab-alip or any of the ingredients in Beyfortus.
Before your child receives Beyfortus, tell your healthcare provider about all of your child's medical conditions, including if your child:
- has ever had a reaction to Beyfortus.
- has bleeding or bruising problems. If your child has a problem with bleeding or bruises easily, an injection could cause a problem.
Tell your healthcare provider about all the medicines your child takes, including prescription and over-the-counter medicines, vitamins and herbal supplements. Your infant should not receive a medicine called palivizumab if they have already received Beyfortus in the same RSV season.
Serious allergic reactions have happened with Beyfortus. Get medical help right away if your child has any of the following signs or symptoms of a serious allergic reaction:
- swelling of the face, mouth, or tongue
- difficulty swallowing or breathing
- unresponsiveness
- bluish color of skin, lips, or under fingernails
- muscle weakness
- severe rash, hives, or itching
The most common side effects of Beyfortus include rash and pain, swelling, or hardness at the site of your child's injection. These are not all the possible side effects of Beyfortus. Call your healthcare provider if you have questions about side effects.
INDICATION
Beyfortus is a prescription medicine used to help prevent a serious lung disease caused by Respiratory Syncytial Virus (RSV) in:
- Newborns and babies under 1 year of age born during or entering their first RSV season.
- Children up to 24 months of age who remain at risk of severe RSV disease through their second RSV season.
Please see the full Prescribing Information including the Patient Information in the adjacent links.
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Frequently asked questions
Can Beyfortus be given with childhood vaccines?
Yes. Beyfortus can be administered at the same time as childhood vaccines.1 Because Beyfortus is a preventive monoclonal antibody and not a vaccine, it does not interfere with the active immune response of other shots. If given during the same visit, the doctor will administer Beyfortus using a separate syringe and a different limb.1
Can you give Beyfortus after RSV infection?
Yes. If your baby has already had an RSV infection, Beyfortus can still be administered. While a prior infection provides some natural immunity, it may not protect against different strains or prevent reinfection later in the season.4 Beyfortus helps ensure that a high level of targeted preventive antibodies remain present throughout the remainder of the typical RSV season to help protect your child against potential reinfection.5
How long do Beyfortus side effects typically last?
For the majority of babies who experience mild side effects, such as redness, swelling, or pain at the injection site, a mild rash, or a temporary fever, the symptoms are typically short-lived.6 These reactions generally appear within a day or two of the shot and resolve on their own within a few days without needing medical attention.6
Is the Beyfortus RSV preventive antibody shot safe?
The RSV preventive antibody shot (Beyfortus) has undergone rigorous clinical testing across multiple trials involving thousands of newborns and infants.1 The most common side effects include rash and pain, swelling or hardness at the site of your child’s injection.1 These are not all of the possible side effects of Beyfortus. Talk to your baby's doctor.
References
- Beyfortus Prescribing Information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/761328s000lbl.pdf, 2023.
- Barbas Del Buey, JF et al. The effectiveness of nirsevimab in reducing the burden of disease due to respiratory syncytial virus (RSV) infection over time in the Madrid region (Spain): a prospective population-based cohort study. Front. Public Health. 2024; 12, 1441786. doi: 10.3389/fpubh.2024.1441786
- Simões, EAF et al. Efficacy of nirsevimab against respiratory syncytial virus lower respiratory tract infections in preterm and term infants, and pharmacokinetic extrapolation to infants with congenital heart disease and chronic lung disease: a pooled analysis of randomised controlled trials. Lancet Child Adolesc. Health. 2023; 7, 180–189. doi: 10.1016/S2352-4642(22)00321-2
- Scott, PD et al. Molecular analysis of respiratory syncytial virus reinfections in infants from coastal Kenya. J. Infect. Dis. 2006; 193, 59–67. doi: 10.1086/498246
- Wilkins, D et al. Durability of neutralizing RSV antibodies following nirsevimab administration and elicitation of the natural immune response to RSV infection in infants. Nat. Med. 2023; 29, 1172–1179. doi: 10.1038/s41591-023-02316-5
- Consolati, A et al. Safety and efficacy of nirsevimab in a universal prevention program of respiratory syncytial virus bronchiolitis in newborns and infants in the first year of life in the Valle d’Aosta region, Italy, in the 2023-2024 epidemic season. Vaccines (Basel). 2024; 12, 549. doi: 10.3390/vaccines12050549
Your child should not take Beyfortus if your child has a history of serious allergic reactions to nirsevimab-alip or any of the ingredients in Beyfortus.
Before your child receives Beyfortus, tell your healthcare provider about all of your child’s medical conditions, including if your child:
- has ever had a reaction to Beyfortus.
- has bleeding or bruising problems. If your child has a problem with bleeding or bruises easily, an injection could cause a problem.
Tell your healthcare provider about all the medicines your child takes, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Your infant should not receive a medicine called palivizumab if they have already received Beyfortus in the same RSV season.
Serious allergic reactions have happened with Beyfortus. Get medical help right away if your child has any of the following signs or symptoms of a serious allergic reaction:
- swelling of the face, mouth, or tongue
- difficulty swallowing or breathing
- unresponsiveness
- bluish color of skin, lips, or under fingernails
- muscle weakness
- severe rash, hives, or itching
The most common side effects of Beyfortus include rash and pain, swelling, or hardness at the site of your child’s injection. These are not all the possible side effects of Beyfortus. Call your healthcare provider if you have questions about side effects.
Please see full Prescribing Information, including Patient Information, for more details.
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Beyfortus is a prescription medicine used to help prevent a serious lung disease caused by Respiratory Syncytial Virus (RSV) in:
- Newborns and babies under 1 year of age born during or entering their first RSV season.
- Children up to 24 months of age who remain at risk of severe RSV disease through their second RSV season.