OBJECTIVE: To determine the potential longer-term effects of maternal antenatal respiratory syncytial virus (RSV) vaccination, we examined the association between cord-blood RSV-neutralizing antibodies (RSV-NA) and RSV infections in the first 2-years of life, RSV-NA at 3-years, and respiratory health to age 5-years. METHODS: Two community-based Australian birth cohorts were combined. For children with at least one atopic parent, paired serum RSV-NA levels were compared in cord-blood and at age 3-years. Weekly nasal swabs were collected in one cohort and during acute respiratory infections (ARI) in the other. Wheeze history up to age 5-years and physician-diagnosed asthma at 5-years was collected by parent report. RESULTS: In 264 children, each log10 increase of cord-blood RSV-NA level was associated with 37% decreased risk (adjusted incidence-rate-ratio (aIRR) 0.63; 95% confidence interval (CI): 0.40-1.01) of RSV-ARI and 49% decreased risk (aIRR 0.51; 95%CI: 0.25-1.02) of RSV acute lower respiratory infections (ALRI) at 12-24 months of age. However, higher cord-blood RSV-NA was associated with increased risk of all-cause ALRI (aIRR 1.29; 95%CI: 0.99-1.69), wheeze-associated ALRI (aIRR 1.75; 95%CI: 1.08-2.82) and severe ALRI (aIRR 2.76; 95%CI: 1.63-4.70) at age 6-<12 months. Cord-blood RSV-NA was not associated with RSV-ARI in the first 6-months, RSV-NA levels at 3-years, or wheeze or asthma at 5-years. CONCLUSIONS: Higher levels of cord-blood RSV-NA did not protect against RSV infections during the first 6-months-of-life, time-to-first RSV-ARI, or wheeze or asthma in the first 5-years of life. Additional strategies to control RSV-related illness in childhood are needed. This article is protected by copyright. All rights reserved.