The antibody will be administered at medical institutions where births or 5-day check-ups take place, as well as in infant health care at primary health centers. Older children in risk groups may also receive the antibody in hospitals or health care facilities.

Why does this matter?

RSV is a common cause of respiratory infections, particularly in the first year of life, and is responsible for numerous hospital admissions both in Iceland and abroad. In severe cases, children may require intensive care and ventilator support.

In recent years, hospital admissions of infants under one year of age have increased in Iceland, and every year some children become critically ill. RSV infections can also lead to bacterial infections, such as pneumonia, which require antibiotic treatment.

How does nirsevimab work?

Nirsevimab is a monoclonal antibody, not a conventional vaccine. It provides immediate protection without requiring activation of the infant’s immune system. Protection lasts for about six months, covering the entire RSV season.

Previously, palivizumab (Synagis®) was available only for preterm infants and children with specific risk factors, but it required repeated doses during the RSV season. Nirsevimab is longer-lasting and requires only a single administration, and is now available to all infants. There is nearly 30 years of experience with palivizumab and other monoclonal antibodies.

Experience abroad

Nirsevimab has already been in use for the past two winters in several European countries and beyond, with very positive results. Its use in infants is supported by pediatric associations in Europe as well as in North and South America. Studies show about an 80% reduction in hospital admissions, as well as fewer cases of bacterial infections that often follow RSV.

Benefits in Iceland

If the results in Iceland are similar to those seen in neighboring countries, we can expect:

• Fewer than 300 children each year needing medical care for RSV infections, instead of around 500 or more.

• About 10–15 hospitalizations instead of around 40 admissions.

• About 30 hospital bed-days instead of 180 days.

Overall, the use of the antibody is expected to reduce illness in children, ease the burden on the health care system, lessen the need for medications, and relieve parents’ worries as well as their absence from work.

Safety

Side effects are usually mild and short-lived, such as fever, redness, or tenderness at the injection site. Serious allergic reactions are very rare. The risk of severe RSV infection is far greater than the risk associated with the antibody.

Importance of participation

For the best results, participation from as many infants under six months of age as possible at the beginning of the RSV season is crucial. Since the antibody provides individual protection rather than herd immunity, the protection of each child is especially important.

Further information about RSV and antibody administration is available on the website of the Directorate of Health.

Chief Epidemiologist

Selected peer-reviewed articles: