Comparison of Respiratory Syncytial Virus (RSV)-Specific Antibody Durability in Pregnant/Postpartum Individuals and Older Adults After RSV Vaccination

Kachikis A, Frivold C, Pike M et al.  J Infect Dis. 2026 Mar 26:jiag111. doi: 10.1093/infdis/jiag111. 

Abstract

Box plots of respiratory syncytial virus (RSV) prefusion F protein
binding antibody titers (A) and neutralizing Ab titers (B), stratified by
study group and collection time point.
Abbreviation: AU, arbitrary units.

Respiratory syncytial virus (RSV) vaccination is recommended in pregnancy. Limited data exist regarding antibody (Ab) durability to inform revaccination timing. We conducted prospective cohort studies among pregnant and older adults after first RSV vaccination in 2023–2024. Longitudinal samples from 50 pregnant (36 vaccinated) and 16 vaccinated older adults were collected until 12–15 months after vaccination and tested for RSV binding and neutralizing Ab.

Mean Ab levels 12–15 months after vaccination were similar between vaccinated maternal and older adult participants (P = .73), suggesting Ab durability up to 1 year after maternal RSV vaccination. RSV binding and neutralizing Ab titers were strongly correlated (R = .73).

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