Nirsevimab (cvx 306)

Nirsevimab is a synthetic antibody that helps protect the body from respiratory syncytial virus (RSV) infection for up to 5 months.

Nirsevimab is used to prevent lung disease from respiratory syncytial virus in newborns and children up to 24 months old.

Nirsevimab may also be used for reasons not mentioned in this medication guide.

Nirsevimab is given one time as an injection (shot) into the leg muscle. A healthcare provider will administer this injection.

If your child is still at increased risk for getting RSV infection or has had heart surgery, your child may receive another dose of this medicine.

Nirsevimab should never be given to a child who has had a severe allergic reaction to it.

Your child should not receive a medicine called palivizumab if they have already received nirsevimab in the same respiratory syncytial virus (RSV) season.

Your child should not receive nirsevimab if they have ever had a life-threatening allergic reaction to any part of nirsevimab or to antibodies known as immunoglobulins.

Your child should not receive a medicine called palivizumab if they have already received nirsevimab in the same RSV season.

Inform your child's doctor if your child has issues with bleeding or bruising.

Get emergency medical help if you see signs of an allergic reaction: hives, trouble breathing, swelling of the face, lips, tongue, or throat.

Call the doctor right away if your child has:

• muscle weakness;
• trouble swallowing;
• blue lips or fingernails; or
• bluish skin.

Common side effects of nirsevimab may include:

• a hard painful lump (induration) at the injection site; or
• rash or swelling at the injection site.

This is not a complete list of side effects, and others may happen. Call your child's doctor for medical advice about side effects. You can report side effects to the FDA at 1 800 FDA 1088.

Usual Pediatric Dose for Respiratory Syncytial Virus:

Recommended dosage: -Neonate and infants born during or entering their first respiratory syncytial virus (RSV) season: 50 mg intramuscularly once (for children less than 5 kg) or 100 mg intramuscularly once (for children 5 kg or greater)-Children up to 24 months of age who remain at increased risk for severe RSV in their second RSV season: A single 200 mg dose intramuscularly, administered as two 100 mg injections (2 x 100 mg). -Children undergoing cardiac surgery with cardiopulmonary bypass: An additional dose is recommended via intramuscular route as soon as the child is stable after surgery to ensure adequate vaccine serum levels. --In the first RSV season: If surgery is within 90 days after receiving the vaccine, the additional dose should be based on current body weight. See above for body weight dosing. If more than 90 days have elapsed since receiving the vaccine, the additional dose should be 50 mg regardless of body weight. --In the second RSV season: If surgery is within 90 days after receiving the vaccine, the additional dose should be 200 mg, regardless of body weight. If more than 90 days have elapsed since receiving the vaccine, the additional dose should be 100 mg regardless of body weight. Use: For active immunization for the prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV) in neonates and infants born during or entering their first RSV season and children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.

Since nirsevimab is given as a one-time injection, your child is not likely to have a dosing schedule.

An overdose of nirsevimab (cvx 306) is unlikely to happen.

Follow your doctor's guidance on any limitations regarding food, drinks, or activities.

Other drugs may affect nirsevimab, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform the doctor about all other medicines your child is taking.

Find detailed information on biosimilars for this medication.