Beyfortus (nirsevimab-alip) Dosage Logo
Get Beyfortus Updates

What parents need to know about Beyfortus® (nirsevimab-alip)
50 mg and 100 mg injection

Beyfortus can help prevent serious lung infections, like pneumonia caused by RSV, in babies under 1 year of age born during or entering their first RSV season.

Stethoscope Icon

Reduced chance of needing medical care due to RSV

This can include trips to the doctor, urgent care, ER, or hospital.
Checkmark Icon

Demonstrated safety and efficacy in babies under age 1

The safety of Beyfortus was found to be similar to placebo in clinical studies. Mild to moderate side effects were seen in about 1 in 100 children. The most common side effects of Beyfortus include rash and pain, swelling, or hardness at the site of your baby’s injection. Serious allergic reactions have happened. These are not all the possible side effects of Beyfortus.
Germ Icon

A breakthrough decades in the making

For almost 60 years, scientists have been trying to develop prevention for RSV disease. In 2016, Beyfortus started its first major clinical trial in babies.

Recommended by the American Academy of Pediatrics (AAP)

Beyfortus has also been added to the approved immunization schedule. This means that it may be available at no cost for parents through the Vaccines for Children (VFC) program and many private health insurance companies.

Smiling Doctor

How Beyfortus works

Beyfortus is a preventative antibody that gives babies the protection against RSV they lack. Antibodies are made naturally by our immune system to fight viruses. But a baby’s immune system might not be strong enough by itself to make enough antibodies to fight RSV. This is where preventative antibodies can add more protection. Beyfortus may not protect all children.

Doctor in hospital looking outwards

Your baby gets Beyfortus

Depending on when they're born, your baby will receive Beyfortus at birth or at a regular checkup during or entering their first RSV season.

Baby being lifted up out of crib by smiling mom

A boosted immune system

Beyfortus gives your baby the antibodies they lack while their immune system is maturing.

Smiling baby in warm clothes sitting in stroller

An extra layer of protection

If your baby comes into contact with RSV, the preventative antibodies in Beyfortus stick to the surface of the virus to help prevent it from infecting the lungs.


When can my baby get Beyfortus?

Snowflake Icon

If your baby is born during RSV season (fall through spring)


  • Beyfortus should be given at birth.
  • If not given in the hospital, they should receive it at their first doctor’s visit.
Sun Icon

If your baby is born in the
spring or summer


  • Your baby can get Beyfortus at a regular checkup, typically just before RSV season.
  • They can get their injection at the same time as other routine childhood vaccines.

How you can take action today

Baby looking over dad's shoulder with sore and stuffy nose

Learn more about RSV

Mom carrying baby

Discover helpful tips for every parent


Additional questions you may have about Beyfortus