Infant RSV admissions in Denmark fell 75 per cent after the maternal vaccine rollout
Denmark began offering an RSV vaccine to pregnant women in autumn 2025. An observational analysis in The Lancet Regional Health - Europe and a University of Copenhagen release calculate that hospital admissions among infants aged 0 to 5 months fell from a three-season average of 1,128 to 296 in 2025-26. Despite 72 per cent uptake, researchers say transmission shifts and testing activity could also have moved the numbers, so causation is not established. The pattern matches experience in Belgium, Spain, the Netherlands, France and England.
Science··Morning
The maternal vaccine programme began in autumn 2025
Denmark began offering an RSV vaccine to pregnant women in autumn 2025. The study from the University of Copenhagen and Nordsjællands Hospital was published in The Lancet Regional Health - Europe and compares the 2025-26 season with the average of the previous three. Uptake reached 72 per cent among eligible pregnant women. RSV can bring severe breathing difficulty in the first months of life, note Thea Kølsen Fischer of the University of Copenhagen and first author Caroline Klint Johannesen.[1], [2]
Admissions fell from a 1,128 average to 296
Hospital admissions among infants aged 0 to 5 months fell from an average of 1,128 across the previous three seasons to 296, a drop of about 75 per cent. The study works out that more than 800 infants avoided hospital admission. The data come from Statens Serum Institut surveillance, pairing hospital stays longer than 12 hours with a positive RSV test. Between 1 October 2025 and 29 April 2026 there were 296 admissions.[1], [2]
Researchers do not pin the drop on the vaccine alone
The researchers say the data cannot pin the drop on the vaccine alone; shifts in transmission patterns and testing activity could also have moved the numbers. Fischer notes that paediatric departments across the country did not see the usual RSV surge this winter. Although the pattern matches RSV vaccination programmes in Belgium, Spain, the Netherlands, France and England, the observational design does not establish causation.[1], [2]
