Beyfortus Side Effects

Generic name: nirsevimab

Medically reviewed by Drugs.com. Last updated on Feb 15, 2025.

Note: This document provides detailed information about Beyfortus Side Effects associated with nirsevimab. Some dosage forms listed on this page may not apply specifically to the brand name Beyfortus.

Applies to nirsevimab: intramuscular solution.

Common side effects of Beyfortus

Some side effects of nirsevimab may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Rare side effects

• bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

Serious side effects of Beyfortus

Along with its needed effects, nirsevimab (the active ingredient contained in Beyfortus) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking nirsevimab:

Incidence not known

• chest tightness
• cough
• difficulty swallowing
• dizziness
• fast heartbeat
• hives, itching, skin rash
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• unusual tiredness or weakness

For healthcare professionals

Applies to nirsevimab: intramuscular solution.

General adverse events

Adverse reactions were reported in 1.2% of patients and most were mild to moderate in intensity.^[Ref]

Dermatologic

• Uncommon (0.1% to 1%): Rash (including rash macular, rash maculopapular, and rash popular)^[Ref]

Local

• Uncommon (0.1% to 1%): Injection site reaction (including injection site pain, injection site induration, injection site edema, and injection site swelling)^[Ref]

Frequently asked questions

• What are the symptoms of RSV (respiratory syncytial virus)?

Further information

Beyfortus side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer