Infants at risk for respiratory syncytial virus (RSV)–associated lower respiratory tract infection responded positively to nirsevimab, a pragmatic study shows, with reduced hospitalizations for RSV-associated lower respiratory tract infection and fewer cases of very severe RSV-associated lower respiratory tract infection.
During their first RSV seasons in France, Germany, or the U.K., infants 12 months of age or younger who had been born at a gestational age of at least 29 weeks received either a single intramuscular injection of nirsevimab or standard care (no intervention). The study used a primary endpoint of hospitalization for RSV-associated lower respiratory tract infection.
“A total of 8,058 infants were randomly assigned to receive nirsevimab (4,037 infants) or standard care (4,021 infants). Eleven infants (0.3%) in the nirsevimab group and 60 (1.5%) in the standard-care group were hospitalized for RSV-associated lower respiratory tract infection, which corresponded to a nirsevimab efficacy of 83.2% (95% confidence interval [CI], 67.8 to 92.0; P <0.001). Very severe RSV-associated lower respiratory tract infection occurred in 5 infants (0.1%) in the nirsevimab group and in 19 (0.5%) in the standard-care group, which represented a nirsevimab efficacy of 75.7% (95% CI, 32.8 to 92.9; P = 0.004). The efficacy of nirsevimab against hospitalization for RSV-associated lower respiratory tract infection was 89.6% (adjusted 95% CI, 58.8 to 98.7; multiplicity-adjusted P <0.001) in France, 74.2% (adjusted 95% CI, 27.9 to 92.5; multiplicity-adjusted P = 0.006) in Germany, and 83.4% (adjusted 95% CI, 34.3 to 97.6; multiplicity-adjusted P = 0.003) in the United Kingdom. Treatment-related adverse events occurred in 86 infants (2.1%) in the nirsevimab group.”
Editorial: “Nirsevimab comes with new challenges alongside its benefits,” writes an editorialist. “As high-income countries begin to implement the administration of nirsevimab, active surveillance for RSV is critical to evaluate the effectiveness of nirsevimab and the evolution of RSV. Equally important are the ‘five A’s’ of health care access — affordability, availability, accessibility, accommodation, and acceptability — especially in low- and middle-income countries, where RSV-associated morbidity and mortality are highest. Ensuring that nirsevimab reaches these vulnerable populations is not only a matter of equity but also imperative to mitigate the global effects of RSV on health and society.”