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Nirsevimab

Beyfortus · ATC code J06BD08

Key facts
Active substance
Nirsevimab
Drug class
Immunoglobulin therapy
ATC code
J06BD08
Authorisation
centrally authorised across the EU (EMA)
Dosage forms
Beyfortus 50 mg solution for injection in pre-filled syringe / Beyfortus 100 mg solution for injection in pre-filled syringe
Marketing authorisation holder
Sanofi Winthrop Industrie
Information as of
2026-10-28

Key facts

Nirsevimab (Beyfortus) is a long-acting monoclonal antibody against respiratory syncytial virus, given to infants and young children as passive immunisation to prevent severe RSV lower respiratory tract disease.

What it is used for

  • Prevention of RSV lower respiratory tract disease in neonates and infants during their first RSV season.
  • Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.
  • Should be used in accordance with official recommendations.

Dosing

  • First RSV season: single dose of 50 mg intramuscularly for body weight <5 kg, 100 mg for ≥5 kg; from birth for infants born during the season, otherwise ideally before the season.
  • Second RSV season: single dose of 200 mg given as two intramuscular injections (2 x 100 mg), ideally before the season starts.
  • After cardiac surgery with cardiopulmonary bypass an additional dose may be given; its size depends on the time since the first dose (see the full text).
  • Limited data in extremely preterm infants; dosing from 1.0 kg to <1.6 kg is based on extrapolation.
  • Inject preferably into the anterolateral thigh; the gluteal muscle should not be used routinely because of sciatic nerve risk.

Contraindications

  • Hypersensitivity to the active substance or any excipient.

Important warnings

  • Serious hypersensitivity reactions have been reported; if anaphylaxis occurs, stop immediately and treat.
  • Caution in thrombocytopenia or coagulation disorders (intramuscular injection).
  • In some immunocompromised children with protein-losing conditions, high clearance may reduce protection.
  • Contains polysorbate 80, which may cause allergic reactions.

Side effects

  • Most frequent: rash (0.7%) within 14 days, mostly mild to moderate.
  • Pyrexia (0.5%) and injection site reactions (0.3%) within 7 days; hypersensitivity (frequency not known).

Interactions

  • No interaction studies; as passive immunisation it is not expected to interfere with the immune response to co-administered vaccines.
  • Does not interfere with RT-PCR or rapid antigen RSV tests.

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Package leaflet, verbatim

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

EU – centrally authorised (all member states)

  • BeyfortusSanofi Winthrop Industrie · EMEA/H/C/005304

Source: European Medicines Agency (EMA), product information

Turkey

  • BeyfortusSANOFİ SAĞLIK ÜRÜNLERİ LTD. ŞTİ. · 5 register entries

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

Brand names in 3 more European countries
Iceland
Beyfortus
Liechtenstein
Beyfortus
Norway
Beyfortus

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

Other substances in the same group

Another question about this substance?

Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.

Sources

  1. European Medicines Agency. Beyfortus – EPAR, Product Information. 2026-10-28. https://www.ema.europa.eu/en/documents/product-information/beyfortus-epar-product-information_en.pdf
  2. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85
  3. Wikidata (CC0): ATC J06BD.

Editorial: Medelix editorial team · last updated 2026-10-28 · How these pages are made · Report an error

Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.