What is RSV?

Respiratory Syncytial Virus (RSV) is a highly contagious virus that can lead to respiratory infection in babies. RSV is most common and spreads most often during the winter virus season (fall through spring) but can vary by local area. 

• Most of the time RSV will cause a mild, cold-like illness.  
• Symptoms of RSV can include congestion, runny nose, irritability, decreased appetite and fever.  
• RSV is unpredictable; it’s hard to know if a baby will have a mild or serious infection—even if they’re born healthy and at full term.
• 2-3% of infants with RSV will require hospitalization.
• Babies are 16x more likely to be hospitalized with RSV than with the flu.
• Learn more about RSV here. 

What is Beyfortus?

Beyfortus is an injection that provides fast-acting protection against serious RSV infection. Beyfortus is recommended for newborns and babies born during or entering their first RSV season. 

How does Beyfortus work?

Beyfortus is not a vaccine. It’s a preventative antibody that gives an extra layer of protection against serious RSV infection. Beyfortus gives your baby about 5 months of protection against serious RSV illness.

When can my baby get Beyfortus?

Beyfortus should be given before the start of your baby’s first RSV season. The typical RSV season usually occurs from fall through spring. Your baby’s doctor can tell you when the RSV season starts in your area.

• If a baby is born during RSV season (October to March) Beyfortus should be given as close to birth as possible. If not given in the hospital, they should receive it as soon as it is available at their doctor’s office.  
• If a baby is born in the spring or summer your baby can get Beyfortus at a regular checkup before RSV season. They can get their injection at the same time as other routine childhood vaccines.

How is BEYFORTUS given?

BEYFORTUS is given as an injection, usually in the thigh (leg) muscle.

Talk with your health care provider.

• Tell your health care provider if the person getting Beyfortus has a:
  • History of serious allergic reactions to an RSV preventive antibody (Beyfortus/Nirsevimab) or any of its components
  • Bleeding disorder
  • Moderate or severe acute illness
  • If mother received an RSV Vaccine during pregnancy  
• In some cases, your child’s health care provider may decide to postpone giving RSV preventive antibodies until a future visit. Depending upon your insurance, there may be instances where an authorization will be needed from your health plan in order to receive Beyfortus.  

How can I learn more?

• Ask your health care provider.
• Visit the CDC website 

Reviewed by:  AR D.O., SL M.D.  | 10/2024