Nirsevimab for Prevention of RSV in Term and Late-Preterm Infants

Infant respiratory syncytial virus infection and childhood asthma: A shift in the paradigm?

“…25 Recently, randomized controlled trials of long-acting RSV monoclonal antibodies and maternal RSV vaccines have been shown to decrease the severity of infant RSV infections (thus preventing infant RSV LRTIs), although it is unknown if these products also prevent infection with this RNA respiratory virus. 26,27 Our findings highlight the importance of observational studies taking advantage of post-approval vaccine uptake and following up with participants enrolled in randomized clinical trials of long-acting monoclonal antibodies and maternal vaccines until older ages to ascertain childhood asthma-related outcomes, recognizing that these trials cannot remain blinded. Our study results also add to emerging literature demonstrating that RNA respiratory viruses may lead to substantial long-term adverse respiratory and other health effects, phenomena that we need to understand to be able to prevent and treat chronic diseases that follow these common infections.…”

Review and Update of Active and Passive Immunization Against Respiratory Syncytial Virus

“…In a phase IIb randomized, placebo-controlled trial of nirsevimab in premature infants (29 weeks to < 37 weeks gestation) without other underlying comorbidities, a single dose of nirsevimab, administered before the start of the RSV season, resulted in 70.1% (95% confidence interval [CI] 52.3-81.2) vaccine efficacy against medically attended RSV-LRTI, and a 78.4% (95% CI 51.9-90.3) lower rate of RSV LRTI hospitalization [114]. In a further randomized, placebocontrolled trial of nirsevimab in late-preterm (> 34 weeks gestation) and term infants (MELODY trial), the efficacy of nirsevimab was 76.4% (95% CI 62.3-85.2) against medically attended RSV LRTI and 76.8% (95% CI 49.4 to 89.4) against hospitalization for RSV LRTI through to 150 days postenrolment [99,115]. Furthermore, nirsevimab may confer protection beyond 180 days, including through the second RSV season up to 510 days post-enrolment, as indicated by a 43% lower risk of medically attended RSV LRTI in the nirsevimab group compared with the placebo group between 361 and 511 days [116].…”

Preventing respiratory syncytial virus bronchiolitis in infants

“…New anti-F antibodies with extended half lives are now becoming available, with one (clesrovimab) in phase 3 trials7 and another (nirsevimab) approved by the European Medicines Agency and the UK Medicines and Healthcare Products Regulatory Agency in 2022. The Melody trial of nirsevimab in healthy term infants recently reported 76.4% (95% confidence interval 62.3% to 85.2%) efficacy against RSV lower respiratory tract infection 150 days after a single intramuscular dose 89…”