Evaluation of the Effectiveness and Impact of Nirsevimab Administered as Routine Immunization

The purpose of this study is to evaluate the impact of nirsevimab in preventing RSV in healthy infants and high-risk children less than 24 months of age at the start of RSV season in Galicia.

The target population to receive nirsevimab is around 14,000 subjects including all healthy newborns during the RSV season, those < 6 months at the start of the season, as well as those < 24 months with comorbidities at the start of the season. Nirsevimab will be administered as part of the immunization program of Galicia and following the implementation plan designed by the Public Health authorities, using the vaccination facilities of the Galician system, i.e., hospitals and primary care centres. Appointments for administration and registration of administered doses will be performed as per usual immunization protocols. The expected coverage with nirsevimab in the target population is expected to be high (>80%).

RSV testing is routinely performed in the hospital and emergency department settings. The Galician Regional Surveillance Information System will retrieve all the existing information of the different electronic databases for new RSV cases detected in Galicia, including hospitalization, primary care, drug administration and immunization. RSV case ascertainment and classification will be per- formed by a specialized clinical team according to pre-established definitions.

Inclusion criteria

• Subjects born in Galicia from April 1st, 2023 and March 1st, 2026

Exclusion criteria

• No specific criteria has been reported