Nirsevimab shows high efficacy against RSV in Canadian infant study

A study conducted across seven Canadian pediatric hospitals has evaluated the real-world effectiveness of nirsevimab, a long-acting monoclonal antibody designed to protect infants from respiratory syncytial virus (RSV).

Unlike traditional vaccines that prompt the body to produce its own defenses, nirsevimab provides infants with ready-made antibodies via injection. The observational study analyzed nearly 2,000 hospital visits for children under one year old presenting with respiratory symptoms.

The research found that among children who tested positive for the virus, only 7% had received the antibody, compared to 30% of those who tested negative. After adjusting for variables such as age, sex, prematurity, and family income, researchers estimated the antibody provides approximately 77% protection against emergency room visits and 79% protection against hospitalizations. Notably, the protection against intensive care unit admission was estimated at 97%.