Press release
Bronchiolitis: protecting babies before they are exposed to the virus
Brussels, 27 August 2026 - Every winter, RSV (respiratory syncytial virus) is the leading cause of bronchiolitis in babies, an infection that is one of the main causes of hospital admission among infants. To protect babies against severe forms of the infection, the Children’s Hospital and Erasme Hospital are organising an immunisation campaign. It involves administering antibodies that provide direct protection against the virus.
The campaign will run from 1 September to 31 October 2026 and is intended for children born between 16 March and 30 September 2026, so that they are protected throughout the period when RSV is circulating. Parents can already make an appointment for the dedicated paediatric consultations organised at the Children’s Hospital and Erasme Hospital.
Children born before 16 March 2026 who have certain risk factors may also be eligible for immunisation. Parents are encouraged to discuss this with their paediatrician to find out whether their child is eligible.
“RSV remains an important cause of hospital admission among babies during the winter months. The data available to us today show that immunisation can significantly reduce this risk. The key is therefore to protect babies at the right time, before they come into contact with the virus,” says Professor Françoise Vermeulen, Head of the Department of Paediatrics at H.U.B.
Immunisation or vaccination: two strategies to protect newborn babies
Immunisation with antibodies is not vaccination. Unlike a vaccine, which stimulates the immune system to produce its own antibodies, immunisation involves administering specific antibodies against RSV directly to the baby by intramuscular injection. Protection is provided rapidly after the injection and lasts throughout the period when the virus is circulating.
Babies who are already born before the start of the RSV season are immunised before or at the beginning of autumn. Babies born during the RSV season can receive this protection from birth, ideally in the maternity unit.
Another option is to vaccinate the mother against RSV during pregnancy. The antibodies produced by the mother are transferred to the baby through the placenta, providing protection during the first months of life.
Immunising the baby and vaccinating the mother therefore have the same objective, but work in two different ways: in one case, antibodies are administered directly to the baby; in the other, they are produced by the mother and transferred to the baby during pregnancy.
In principle, only one of these two strategies is needed to protect the child.
Bronchiolitis, a common infection in babies
RSV is highly contagious and circulates mainly during autumn and winter. The virus can be transmitted through coughing and sneezing, as well as via hands or contaminated objects.
In most children, the infection resolves without serious complications. In babies, particularly the youngest or most vulnerable, however, it can cause breathing or feeding difficulties and may require hospital admission.
Reimbursed immunisation
This immunisation is largely reimbursed for children who meet the eligibility criteria, leaving families to pay only the applicable patient contribution.
The immunisation campaign will run from 1 September to 31 October 2026 at the Children’s Hospital (HUDERF) and Erasme Hospital.
Frédérique Meeus
Maxime Rotsaert