Prevention of Respiratory Syncytial Virus (RSV) Lower Respiratory Tract Disease:
Neonates and Infants: During their first RSV season.
Children up to 24 Months: Who remain vulnerable to severe RSV disease through their second RSV season. This includes children with chronic lung disease of prematurity (CLD), hemodynamically significant congenital heart disease (CHD), immunocompromised states, Down syndrome, cystic fibrosis, neuromuscular disease, and congenital airway anomalies.
Dosage and Administration
Recommended Dose:
Neonates and Infants (First RSV Season):
<5 kg: Single fixed dose of 50 mg.
≥5 kg: Single fixed dose of 100 mg.
Children (Second RSV Season):
Single dose of 200 mg given as two intramuscular injections of 100 mg each.
Post-Cardiac Surgery:
Additional dose recommended post-surgery to ensure adequate nirsevimab serum levels.
Administration: Administer intramuscularly, preferably in the anterolateral aspect of the thigh. Different injection sites should be used if two injections are required.
Contraindications
Severe hypersensitivity reactions, including anaphylaxis, to any component of BEYFORTUS.
Warnings and Precautions
Hematologic: Use with caution in individuals with bleeding disorders or on anticoagulation therapy.
Hypersensitivity: Serious reactions including anaphylaxis have been observed.
Special Populations:
Pregnant Women and Breastfeeding: BEYFORTUS is not indicated for adults.
Pediatrics: Safety and efficacy not established for children older than 24 months or infants below 1.6 kg.
Geriatrics: Not indicated for adults.
Adverse Reactions
Common: Rash (0.7%), pyrexia (0.5%), injection site reactions (0.3%).
Clinical Trial Findings:
In term and preterm infants, the overall adverse event rates were comparable to placebo.
Most common adverse events included upper respiratory tract infection, nasopharyngitis, and pyrexia.
Drug Interactions
Concomitant Vaccination: Can be administered with routine childhood vaccines, but should not be mixed in the same syringe or vial. Administer at different injection sites.
Storage and Stability
Storage: Store in a refrigerator (2°C to 8°C). Do not freeze. Use within 8 hours after removal from refrigeration. Protect from light.
Clinical Trials and Efficacy
Study 3 and MELODY: Demonstrated significant reduction in medically attended RSV lower respiratory tract infection (LRTI) and RSV hospitalization in infants entering their first RSV season.
Efficacy: 70.1% reduction in RSV LRTI in preterm infants (Study 3) and 74.5% in term and late preterm infants (MELODY).
MEDLEY: Comparable safety profile to palivizumab in high-risk infants, including those with CLD or CHD.
MUSIC: Evaluated safety in immunocompromised children, consistent with the safety profile observed in other trials.
