# Prevention of severe RSV disease in babies Keywords: - [RSV](< /en/search?q=RSV >) - [RSV-hengitystieinfektio](< /en/search?q=RSV-hengitystieinfektio >) - [New Children’s Hospital](< /en/search?q=New Children’s Hospital >) - ... Show all keywords - [Women’s Hospital](< /en/search?q=Women’s Hospital >) - [Espoo Hospital](< /en/search?q=Espoo Hospital >) - [Jorvi Hospital](< /en/search?q=Jorvi Hospital >) - [Hyvinkää Hospital](< /en/search?q=Hyvinkää Hospital >) - [Lohja Hospital](< /en/search?q=Lohja Hospital >) RSV (respiratory syncytial virus) is the most common cause of respiratory infections leading to infant hospitalization. We offer an antibody developed against the RS virus called nirsevimab in our hospitals to infants and children under the age of 12 months who are at risk of severe RSV infection.  The aim of nirsevimab is to prevent the majority of severe illnesses and infant hospitalizations caused by RSV. Nirsevimab is offered to - Infants born at HUS maternity hospitals from September 4, 2025 - Children under the age of 12 months who belong to high-risk groups for severe RSV infection when they have an appointment in specialized healthcare at HUS New Children's Hospital, Jorvi Hospital, or Hyvinkää Hospital. Immunization with nirsevimab is voluntary and free of charge for families. ## At-risk groups: • Heart defect or heart disease for which surgery is planned or regular medication is needed. • Severe immunodeficiency according to the attending physician • Lung disease in a premature infant, i.e. bronchopulmonary dysplasia, for which some form of respiratory support treatment has been needed in the past 6 months or similar severe chronic pulmonary disease • Down syndrome ## Information on the RS virus and nirsevimab ### What is the RS virus? --- RSV or RS virus (*respiratory syncytial virus*) is a common cause of respiratory tract infection in people of all ages. The number of cases tends to increase in late fall and in the winter. The infection spreads easily through, for example, hand contact and sneezing. Almost all children get a respiratory tract infection caused by RSV during early childhood. Most only experience mild cold-like symptoms. ### RSV can be serious for small babies and those at risk --- RSV is a common cause of hospitalization in babies. In children under twelve months of age (and especially children under three months of age), the virus can cause a lower respiratory tract infection with symptoms such as cough, increased mucus/phlegm production, loss of appetite, fatigue, rapid and superficial breathing, and pauses in breathing. Symptoms can get worse quickly and require urgent hospitalization or even intensive care. ### Nirsevimab is an antibody against the RS virus --- Nirsevimab is effective in preventing severe RSV infections. The medicine starts to work almost immediately, and its effect lasts for one RSV season. The antibody is at its most useful when given at the start of the RSV season. Nirsevimab is administered as a single intramuscular injection. It is not a vaccine. Nirsevimab can be given at the same time as vaccines from the vaccination program. If the mother was vaccinated against RSV during pregnancy at least 2 weeks before giving birth, the baby will not need nirsevimab. Nirsevimab has been shown to be very safe in clinical studies. The medicine does not contain RSV and cannot cause an RSV infection. Adverse effects are relatively rare. Potential adverse effects include rash, fever, and redness, swelling, or pain at the injection site. Updated: 09.01.2026 Print this page