BEYFORTUS 50 mg
NIRSEVIMAB
What it does
Nirsevimab is a medication used to help protect infants from respiratory syncytial virus (RSV), a common virus that can cause serious breathing problems.
Commonly used for: protection against respiratory syncytial virus (RSV), prevention of severe respiratory illness in infants
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Source: South African Health Products Regulatory Authority · fetched 2026-04-15 21:30:04 · updated 2026-09-30 04:12:31
About this medicine
Nirsevimab is a medication used to help protect infants from respiratory syncytial virus (RSV), a common virus that can cause serious breathing problems.
What it treats
- protection against respiratory syncytial virus (RSV)
- prevention of severe respiratory illness in infants
How it works
Nirsevimab works by helping the immune system fight off the RSV virus, reducing the risk of severe respiratory infections.
Who it's for
This medication is for infants, especially those at high risk of severe RSV infections.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: nirsevimab
Nirsevimab is a monoclonal antibody designed for the prevention of respiratory syncytial virus (RSV) infection in infants and young children. It is a single-dose therapy that provides passive immunity against RSV, reducing the risk of severe respiratory illness associated with the virus. Nirsevimab has been developed to offer protection throughout the RSV season, making it particularly beneficial for high-risk populations.
Indications
- Prevention of respiratory syncytial virus (RSV) infection in infants and young children at high risk for RSV disease
Dosage
Children: Refer to the BNF for Children for specific dosing recommendations.
Mechanism of action
Nirsevimab binds to the F protein of RSV, preventing the virus from entering and infecting host cells. By neutralizing the virus, it inhibits viral replication and subsequent infection, thereby providing a protective effect against RSV disease. Its design allows for enhanced binding affinity and longevity of action compared to traditional palivizumab therapies.
Pharmacodynamics
The pharmacodynamics of nirsevimab involve its ability to provide a long-lasting immune response, reducing the incidence of RSV-associated hospitalizations and severe disease in infants. By blocking the entry of RSV into cells, nirsevimab effectively lowers viral load, thus mitigating the severity of respiratory symptoms and complications that arise from an RSV infection.
Pharmacokinetics
Nirsevimab has a long half-life, which allows for extended duration of action with a single administration. It is administered via intramuscular injection, with peak serum concentrations occurring within a few days post-injection. The drug is primarily distributed in the bloodstream and has a low volume of distribution, indicating that it remains largely within the vascular compartment. Nirsevimab is expected to be metabolized through standard protein catabolism pathways in the body.
Adverse effects
- Injection site reactions
- Fever
- Rash
- Hypersensitivity reactions
Precautions
- Monitor for signs of hypersensitivity
- Use caution in patients with a history of severe allergies
Pregnancy
Animal studies have not demonstrated direct or indirect harmful effects with respect to reproductive toxicity. However, there are limited data in pregnant women.
Breast-feeding
It is unknown whether nirsevimab is excreted in human milk. Caution should be exercised when administering to a nursing mother.
Storage
Store in a refrigerator (2°C to 8°C). Do not freeze. Protect from light.
Formulations
- Injectable solution
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.