Amanda B. Payne , Steph Battan-Wraith , Elizabeth A.K. Rowley , Melissa S. Stockwell , Sara Y. Tartof , Kristin Dascomb , Stephanie A. Irving , Brian Dixon , Sarah W. Ball , Mark W. Tenforde , Gabriela Vazquez-Benitez , Ashley B. Stephens , Jungmi Han , Karthik Natarajan , S. Bianca Salas , Cassandra Bezi , Lina S. Sy , Bruno Lewin , Tamara Sheffield , Julie Arndorfer , Ruth Link-Gelles
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引用次数: 0
Abstract
Background
In August 2023, the Centers for Disease Control and Prevention recommended nirsevimab, a long-acting monoclonal antibody, for all U.S. infants aged <8 months entering or born during their first respiratory syncytial virus (RSV) season. Our aim was to estimate nirsevimab effectiveness against RSV-associated emergency department (ED) encounters and hospitalisation among U.S. infants during the 2023–2024 RSV season.
Methods
We conducted a test-negative analysis using electronic health record (EHR) data from 6 healthcare systems, including ED encounters and hospitalizations with a diagnosis of RSV-like illness (RLI) during October 8, 2023–March 31, 2024, among infants aged <8 months as of October 1, 2023, or born during the study period. Nirsevimab effectiveness was estimated by comparing children who received nirsevimab with those who did not among RSV-positive and RSV-negative encounters, adjusting for age, race and ethnicity, sex, calendar day, and geographic region and excluding infants whose mother received RSV vaccination during pregnancy.
Findings
Among 5039 ED encounters with RLI among infants in their first RSV season, 2045 (41%) were RSV-positive and 446 (9%) received nirsevimab, with a median time since dose of 52 days (interquartile range [IQR]: 27–84 days). Among 1025 hospitalizations with RLI among infants in their first RSV season, 605 (59%) were RSV-positive and 95 (9%) received nirsevimab, with a median time since dose of 48 days (IQR: 24–82 days). Nirsevimab effectiveness was 77% (95% CI: 69%–83%) against RSV-associated ED encounters and 98% (95% CI: 95%–99%) against RSV-associated hospitalisation.
Interpretation
Nirsevimab was effective in preventing RSV-associated ED encounters and hospitalisation among infants in their first RSV season, with greatest protection against hospitalisation. However, these estimates reflect a short interval from nirsevimab administration to RLI onset. Since nirsevimab is a passive immunization and concentration is expected to wane over time, it is important to continue monitoring effectiveness to assess effectiveness with increased time since dose.
Funding
This work was supported by the Centers for Disease Control and Prevention (contracts 75D30121D12779 to Westat and 75D30123C18039 to Kaiser Foundation Hospitals).
期刊介绍:
The Lancet Regional Health – Americas, an open-access journal, contributes to The Lancet's global initiative by focusing on health-care quality and access in the Americas. It aims to advance clinical practice and health policy in the region, promoting better health outcomes. The journal publishes high-quality original research advocating change or shedding light on clinical practice and health policy. It welcomes submissions on various regional health topics, including infectious diseases, non-communicable diseases, child and adolescent health, maternal and reproductive health, emergency care, health policy, and health equity.