Public Health Impact of Nirsevimab Against Lower Respiratory Infections Associated with Respiratory Syncytial Virus Among Chinese Infants

OBJECTIVES: To assess the impact of nirsevimab, a new extended half-life monoclonal antibody, on respiratory syncytial virus lower respiratory tract infections (RSV-LRTI) events and associated costs for all infants in their first RSV season in China.

METHODS: A static decision-analytic model was developed to assess the impact of nirsevimab compared to the status quo of no intervention. The analysis was conducted within the first RSV season of a national birth cohort in 2020, separately for preterm and term infants. The model incorporated domestic inputs pertaining to RSV-LRTI burden, costs and other parameters derived from literature. Health outcomes included RSV-LRTI cases, hospitalization involving intensive care unit admission and mechanical ventilators use, in-hospital deaths and quality-adjusted life years (QALYs).

RESULTS: In the status quo in 2020, a total of 1,094,442 RSV-LRTI cases (including 594,454 hospital admissions), 4,564 in-hospital deaths, 153,903 QALY loss and $1,706 million associated costs were observed, where preterm infants (5.23% of the birth cohort) accounted for 6.15% of inpatient stays, 14.18% of in-hospital deaths and 9.13% of costs. By comparison, the administration of nirsevimab with 20% coverage for preterm infants and 10% for term infants was predicted to avert 78,597 RSV-LRTI cases (44,497 hospital admissions), 369 in-hospital deaths and 12,260 QALY loss, saving $131 million. Improved coverage to 60% for preterm infants and 30% for term infants would result in larger decreases in RSV-LRTI health and economic burden, averting 235,791 RSV-LRTI cases (133,493 hospital admissions), 1,107 in-hospital deaths and 36,780 QALY loss, and saving $393 million in costs.

CONCLUSIONS: Considering the substantial RSV health and economic burden on Chinese infants in their first RSV season, nirsevimab introduction serves as an effective measure in mitigating this burden. The findings underscore the significance of preventive measures and advocate for further improvement in coverage, which would yield considerable benefits to public health.