The duration of protection is between 5-6 months. RSV antibody titers remained high 6 months after birth in infants born to mothers vaccinated with the maternal RSVPreF vaccine. Similarly, efficacy outcomes measured at 5 months after nirsevimab administration indicated protection at 5 months. Go to footnote 1, Go to footnote 2, Go to footnote 3
- Go back to footnote reference 1
United States Food and Drug Administration (2023). Vaccines and Related Biological Products Advisory Committee meeting, 18 May 2023: FDA briefing document. Silver Spring (MD): US FDA (https://www.fda.gov/media/168185/download, accessed 20 June 2025).
- Go back to footnote reference 2
Kampmann B, Madhi SA, Munjal I, Simões EAF, Pahud BA, Llapur C, et al. (2023). Bivalent prefusion F vaccine in pregnancy to prevent RSV illness in infants. N Engl J Med. 388:1451–64.
- Go back to footnote reference 3
Simões EAF, Madhi SA, Muller WJ, Atanasova V, Bosheva M, Cabañas F, et al. (2023). Efficacy of nirsevimab against respiratory syncytial virus lower respiratory tract infections in preterm and term infants, and pharmacokinetic extrapolation to infants with congenital heart disease and chronic lung disease: a pooled analysis of randomized controlled trials. Lancet Child Adolesc Health. 7(3):180–89. doi:10.1016/S2352-4642(22)00321-2.
