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Published on: January 26, 2019
Effectiveness of Nirsevimab Immunoprophylaxis Administered at Birth to Prevent Infant Hospitalisation for Respiratory
Guillermo Ezpeleta1, Ana Navascués2,3, Natividad Viguria3,4
1Instituto de Salud Pública de Navarra, 31003 Pamplona, Spain.
Insights
Nirsevimab immunoprophylaxis significantly reduced hospitalizations for respiratory syncytial virus (RSV) in infants. This study shows nirsevimab is highly effective in preventing RSV infections during the first RSV season.
Area of Science:
- Pediatrics
- Infectious Diseases
- Public Health
Background:
- Respiratory syncytial virus (RSV) is a major cause of infant hospitalizations.
- Nirsevimab immunoprophylaxis is approved for preventing RSV-associated lower respiratory tract disease in infants.
Purpose of the Study:
- To evaluate nirsevimab's effectiveness in preventing RSV hospitalizations.
- To assess the impact of a birth immunisation strategy for RSV prevention.
Main Methods:
- Population-based cohort study in Navarre, Spain (Oct-Dec 2023 births).
- Cox regression analysis to compare hospitalization rates between nirsevimab-immunized and non-immunized infants.
- PCR confirmation for RSV infection.
Main Results:
- 88.7% effectiveness of nirsevimab in preventing RSV hospitalizations.
- Hospitalization risk reduced from 8.5% in non-immunized to 0.7% in immunized infants.
- One hospitalization prevented for every 15.3 infants immunized at birth.
Conclusions:
- Nirsevimab immunisation at birth is effective in preventing RSV hospitalizations.
- Recommending nirsevimab for infants born during or before the RSV season can reduce severe infections and hospital burden.
- This strategy could prevent a significant proportion of RSV hospitalizations in infants.
Abstract:
Respiratory syncytial virus (RSV) infection is a frequent cause of hospitalisation in the first few months of life; however, this risk rapidly decreases with age. Nirsevimab immunoprophylaxis was approved in the European Union for the prevention of RSV-associated lower respiratory tract disease in infants during their first RSV season. We evaluated the effectiveness of nirsevimab in preventing hospitalisations for confirmed RSV infection and the impact of a strategy of immunisation at birth. A population-based cohort study was performed in Navarre, Spain, where nirsevimab was offered at birth to all children born from October to December 2023. Cox regression was used to estimate the hazard ratio of hospitalisation for PCR-confirmed RSV infection between infants who received and did not receive nirsevimab. Of 1177 infants studied, 1083 (92.0%) received nirsevimab. The risk of hospitalisation for RSV was 8.5% (8/94) among non-immunised infants versus 0.7% (8/1083) in those that were immunised. The estimated effectiveness of nirsevimab was 88.7% (95% confidence interval, 69.6-95.8). Immunisation at birth of infants born between October and December 2023 prevented one hospitalisation for every 15.3 immunised infants. Immunisation of children born from September to January might prevent 77.5% of preventable hospitalisations for RSV in infants born in 2023-2024. These results support the recommendation of nirsevimab immunisation at birth to children born during the RSV epidemic or in the months immediately before to prevent severe RSV infections and alleviate the overload of paediatric hospital resources.
