Denmark’s maternal RSV vaccine rollout cuts infant hospital admissions by 75%

Hospital admissions among Danish babies aged under six months fell from an average of 1,128 to 296 after pregnant women were offered RSV vaccination, researchers say.

Denmark’s new RSV vaccination programme for pregnant women appears to have delivered a swift and substantial drop in hospital admissions among the youngest infants, according to researchers from the University of Copenhagen and Nordsjællands Hospital. Their study found that admissions of babies aged 0 to 5 months fell by 75 per cent during the 2025/26 season compared with the average of the previous three winters, suggesting that maternal vaccination may be shielding newborns during the period when they are most vulnerable.

The figures are striking in a country where RSV typically surges in the colder months and places heavy pressure on paediatric wards. Denmark recorded an average of 1,128 admissions among infants in the three earlier seasons covered by the study, but only 296 between October and April in the most recent one. The researchers said the reduction meant more than 800 babies avoided hospital care over the winter, a result they described as especially important because RSV can cause serious breathing problems in very young children and disrupt family life as well as hospital services.

The programme began in autumn 2025, when pregnant women in Denmark were offered the RSV vaccine to protect their babies in the first months after birth. The Danish Health Authority says the injection is recommended around the third antenatal appointment, usually in week 32 of pregnancy, and is offered within a set window that aligns with the virus’s seasonal pattern. According to the authority, more than 16,000 women have taken up the vaccine, while the study found 72 per cent of those eligible accepted it in the first season.

Researchers say Denmark’s experience is in line with early results reported in other European countries that have introduced similar programmes, including Belgium, Spain, the Netherlands, France and England. They also noted that vaccination is unlikely to eliminate RSV altogether because the virus is both common and highly contagious, but it could sharply reduce severe illness. Danish authorities have also extended support for vaccination against RSV to older adults at increased risk, including those over 60 with conditions such as chronic obstructive pulmonary disease, in an effort to reduce the wider burden of respiratory illness on the health system.