20th October 2026
20th October 2026
RSV Prevention in Infants: Encouraging Results and Next Steps
Routine immunisation against respiratory syncytial virus (RSV) was introduced in Iceland in autumn 2025, with very encouraging results during the first season.
Uptake among parents was excellent, and preliminary findings indicate a substantial reduction in severe RSV infections among the youngest infants. The Minister of Health has now decided to secure permanent funding for these preventive measures, and preparations are underway for an ongoing programme.
RSV is a common cause of respiratory infections in young children and can lead to serious illness, particularly during the first months of life. To prevent such illness, infants in Iceland were offered the long-acting monoclonal antibody nirsevimab (Beyfortus) for the first time last winter. It is administered as a single injection and provides protection for at least five to six months.
How was the programme organised?
When the decision was made in spring 2025 to introduce these immunisations, the initiative was initially planned as a temporary two-season programme covering the winters of 2025–2026 and 2026–2027. This required defining the eligible groups and determining the quantity of antibody to be purchased for both seasons.
Priority was given to the youngest infants, as the risk of severe RSV disease is highest during the first months of life. The age criteria were based on Icelandic data on RSV-related hospitalisations and the international research available at the time.
Under the current programme, the antibody is offered to infants born during the defined RSV season, from October through March, and to infants born from May through September before the season. For the 2026–2027 season, this includes infants born on or after 1 May 2026, following the same eligibility criteria as the previous season. The antibody is also offered to certain children at increased risk of severe RSV disease during their second year of life.
These age criteria reflect the initial prioritisation of the youngest infants; they do not mean that the antibody benefits only infants younger than six months. Although the risk of severe illness generally decreases with age, there is no sharp biological distinction between infants born at the end of one month and those born at the beginning of the next. International studies have shown that older infants may also benefit from receiving the antibody.
Procurement was planned well in advance based on the eligible population defined for the programme. Manufacturing and delivery take time, so expanding eligibility at short notice is not straightforward once supplies for a particular season have already been ordered.
Encouraging Results from the First RSV Season
Uptake of nirsevimab during the 2025–2026 season was very high, with the vast majority of parents accepting the offer for their infants.
Preliminary Icelandic data indicate a substantial reduction in RSV-related hospitalisations among children under one year of age. There are also indications of fewer primary care visits for respiratory symptoms and reduced use of certain medications.
These encouraging preliminary findings are consistent with the positive results reported in international studies. Further analysis is ongoing, particularly as the RSV season started later and RSV activity was lower last winter than in previous years.
What Happens Next?
Following the Minister of Health's decision to secure permanent funding, RSV prevention can now be planned on a longer-term basis, with the programme to be reassessed for the 2027–2028 season and beyond.
The Chief Epidemiologist will assess whether eligibility should be expanded so that more infants receive protection during their first RSV season. One option under consideration is to offer the antibody to all infants during their first RSV season, either shortly after birth or before the season begins, depending on when they are born.
This assessment will draw on the latest international research and Icelandic data on hospitalisations, illness and use of healthcare services. Data from last winter are currently being analysed, and RSV activity during the coming winter will also be closely monitored.
As supplies must be secured well in advance, procurement decisions for the next season will need to be based on the best available evidence at the time, even if the final evaluation of both initial seasons has not yet been completed.
The aim is to ensure that as many children as possible are protected against severe RSV disease, and that Iceland's RSV immunisation programme reflects the latest scientific evidence and local circumstances.
The Chief Epidemiologist