RSV protection from infant immunisation does not last into second year, JAMA study finds
During the first year of follow-up, nirsevimab was associated with reduced RSV hospitalisations.
Infant RSV immunisation is not associated with a reduced risk of RSV hospitalisation in the subsequent season, a study in JAMA Pediatrics has found.
The French cohort study looked at infants who received one dose of nirsevimab in 2023, those who received one dose in 2024 and unimmunised infants.
First-year follow-up began on the immunisation date — or the corresponding matched date for unimmunised infants — and continued until 31 August the next year, or in the case of the 2023 cohort, for two years.
The study included 74,672 infants in 2023 and 175,526 in 2024. The average age of immunised infants was 4.5 and 4.8 months, respectively.
