Fecha de publicación: -- Fuente: PubMed "nature biotechnology" Clin Microbiol Infect. 2026 Nov 7:S1198-743X(26)00622-1. doi: 10.1016/j.cmi.2026.11.003. Online ahead of print.ABSTRACTOBJECTIVES: Maternal antibodies provide early-life protection against severe respiratory syncytial virus (RSV) infection but wane rapidly. With the availability of maternal vaccine and half-life extended monoclonal antibodies for infants, understanding transplacental antibody transfer and subsequent antibody dynamics is important for optimising immunisation strategies.METHODS: We conducted a longitudinal cohort study of 695 mother-neonate pairs in southern China between 2013 and 2021. Serum samples were collected from mothers at delivery and from children at birth, 2, 4, 6, 12, 24, 36 months, and 5-8 years of age. All samples were tested for RSV pre-F IgG antibodies using an enzyme-linked immunosorbent assay. A subset of samples was additionally tested for neutralizing antibodies (nAbs) using a foci reduction neutralization test.RESULTS: Maternal and cord blood RSV pre-F IgG antibody levels were positively correlated ( = 0.87; P<0.001) with a mean transplacental transfer ratio of 1.44 (95% confidence interval [CI]: 1.40-1.47). A 10-fold increase in maternal antibody levels was associated with a 6.46-fold increase in cord blood antibody levels, corresponding to a 35% decrease in transplacental transfer ratios. Preterm birth was associated with 17% lower cord blood antibody levels than full-term birth. Maternally derived antibodies declined rapidly after birth, with an estimated half-life of 34.3 days (95% CI, 33.9-34.8); antibody levels reached a nadir at approximately 10 months of age and gradually increased thereafter. RSV pre-F IgG and nAb titers from children were strongly correlated (repeated-measures correlation: = 0.846, P < 0.001), and the correlation persisted after adjustment for age ( = 0.743, P < 0.001).CONCLUSIONS: Our findings highlight the importance of addressing lower maternally derived antibody levels in preterm infants, particularly in the context of maternal immunisation. Longitudinal antibody dynamics reveal a distinct period of low antibody levels during infancy that may inform the timing of targeted RSV immunisation strategies.PMID:42998879 | DOI:10.1016/j.cmi.2026.11.003