Early Estimate of Nirsevimab Effectiveness for Prevention of Respiratory Syncytial Virus–Associated Hospitalization Among Infants Entering Their First Respiratory Syncytial Virus Seaso

Madison Gordon 8 months ago 2 min read

A recent study on the effectiveness of nirsevimab in preventing respiratory syncytial virus (RSV) hospitalizations in infants has shown promising results. The analysis, which looked at 699 infants hospitalized with acute respiratory illness during their first RSV season, found that nirsevimab was 90% effective in preventing RSV-associated hospitalization.

The study, which observed the effectiveness of nirsevimab at a median of 45 days from receipt of the medication to symptom onset of acute respiratory illness, supports recommendations for preventing severe RSV disease in infants during their first RSV season. However, the study also pointed out that effectiveness may decrease over a full RSV season due to waning antibody levels from passive immunization.

Clinical trials have shown that nirsevimab remains effective against RSV-associated lower respiratory tract infections for up to 150 days after receipt, indicating its potential to protect high-risk infants aged 8-19 months. Despite some limitations in the study, such as a small proportion of infants receiving nirsevimab and potential RSV infections before medication receipt, the importance of nirsevimab in preventing RSV-associated hospitalizations in infants is underscored.

Public health recommendations continue to support maternal RSV vaccination or infant receipt of nirsevimab to reduce the risk of severe RSV disease in infants during their first RSV season. The study highlights the potential of nirsevimab as a valuable tool in the fight against RSV and its impact on infant health.