Moline Heidi L, Toepfer Ariana P, Tannis Ayzsa, Weinberg Geoffrey A, Staat Mary A, Halasa Natasha B, Boom Julie A, Klein Eileen J, Williams John V, Schuster Jennifer E, Goldstein Leah, McKeever Erin R, Kalman Casey, Paden Clinton, Atherton Lydia, Aggarwal Megha, Roychoudhury Pavitra, Piedra Pedro A, Sahni Leila C, Stewart Laura S, Selvarangan Rangaraj, Michaels Marian G, Schlaudecker Elizabeth P, Szilagyi Peter G, Englund Janet A, Clopper Benjamin R, Thornburg Natalie J, Derado Gordana, McMorrow Meredith L, Dawood Fatimah S
Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
US Public Health Service, Rockville, Maryland.
JAMA Pediatr. 2025 Feb 1;179(2):179-187. doi: 10.1001/jamapediatrics.2024.5572.
During the 2023-2024 respiratory syncytial virus (RSV) season in the United States, 2 new RSV prevention products were recommended to protect infants in their first RSV season: nirsevimab and Pfizer's maternal RSV vaccine. Postlicensure studies are needed to assess prevention product impact and effectiveness.
To compare the epidemiology and disease burden of medically attended RSV-associated acute respiratory illness (ARI) among children younger than 5 years during the 2023-2024 RSV season with 3 prepandemic RSV seasons (2017-2020), estimate nirsevimab effectiveness against medically attended RSV-associated ARI, and compare nirsevimab binding site mutations among circulating RSV in infants with and without nirsevimab receipt.
DESIGN, SETTING, AND PARTICIPANTS: This study included prospective population-based surveillance for medically attended ARI with systematic molecular testing for RSV and whole-genome sequencing of RSV positive samples, as well as a test-negative case-control design to estimate nirsevimab effectiveness. The study was conducted in 7 academic pediatric medical centers in the United States with data from RSV seasons (September 1 through April 30) in 2017 through 2020. Participants were children younger than 5 years with medically attended ARI.
For the nirsevimab effectiveness analyses, nirsevimab receipt among infants younger than 8 months as of or born after October 1, 2023.
Medically attended RSV-associated ARI.
Overall, 28 689 children younger than 5 years with medically attended ARI were enrolled, including 9536 during September 1, 2023, through April 30, 2024, and 19 153 during the same calendar period of 2017-2020. Of these children, 16 196 (57%) were male, and 12 444 (43.4) were female; the median (IQR) age was 15 (6-29) months. During 2023-2024, the proportion of children with RSV was 23% (2199/9490) among all medically attended episodes, similar to 2017-2020. RSV-associated hospitalization rates in 2023-2024 were similar to average 2017-2020 seasonal rates with 5.0 (95% CI, 4.6-5.3) per 1000 among children younger than 5 years; the highest rates were among children aged 0 to 2 months (26.6; 95% CI, 23.0-30.2). Low maternal RSV vaccine uptake precluded assessment of effectiveness. Overall, 10 of 765 case patients (1%) who were RSV positive and 126 of 851 control patients (15%) who were RSV negative received nirsevimab. Nirsevimab effectiveness was 89% (95% CI, 79%-94%) against medically attended RSV-associated ARI and 93% (95% CI, 82%-97%) against RSV-associated hospitalization. Among 229 sequenced specimens, there were no differences in nirsevimab binding site mutations by infant nirsevimab receipt status.
This analysis documented the continued high burden of medically attended RSV-associated ARI among young children in the US. There is a potential for substantial public health impact with increased and equitable prevention product coverage in future seasons.
在美国2023 - 2024年呼吸道合胞病毒（RSV）流行季，推荐了2种新的RSV预防产品来保护处于首个RSV流行季的婴儿：nirsevimab和辉瑞的母体RSV疫苗。需要进行上市后研究来评估预防产品的影响和效果。
比较2023 - 2024年RSV流行季5岁以下儿童中因医学就诊的RSV相关急性呼吸道疾病（ARI）的流行病学和疾病负担与3个大流行前RSV流行季（2017 - 2020年），估计nirsevimab对因医学就诊的RSV相关ARI的有效性，并比较接受和未接受nirsevimab的婴儿中循环RSV的nirsevimab结合位点突变情况。
设计、设置和参与者：本研究包括基于人群的前瞻性监测，对因医学就诊的ARI进行RSV系统分子检测和RSV阳性样本的全基因组测序，以及采用检测阴性病例对照设计来估计nirsevimab的有效性。该研究在美国7个学术性儿科医疗中心进行，数据来自2017年至2020年的RSV流行季（9月1日至4月30日）。参与者为5岁以下因医学就诊的ARI儿童。
对于nirsevimab有效性分析，截至2023年10月1日或之后出生的8个月以下婴儿接受nirsevimab的情况。
因医学就诊的RSV相关ARI。
总体而言，纳入了28689名5岁以下因医学就诊的ARI儿童，其中包括2023年9月1日至2024年4月30日期间的9536名以及2017 - 2020年同一日历期间的19153名。这些儿童中，16196名（57%）为男性，12444名（43.4%）为女性；年龄中位数（IQR）为15（6 - 29）个月。在2023 - 2024年期间，所有因医学就诊的病例中RSV感染儿童的比例为23%（2199/9490），与2017 - 2020年相似。2023 - 2024年RSV相关住院率与2017 - 2020年平均季节率相似，5岁以下儿童中每1000人中有5.0（95%CI，4.6 - 5.3）；最高发生率在0至2个月的儿童中（26.6；95%CI，23.0 - 30.2）。母体RSV疫苗接种率低，无法评估其有效性。总体而言，765例RSV阳性病例患者中有10例（1%）和851例RSV阴性对照患者中有126例（15%）接受了nirsevimab。Nirsevimab对因医学就诊的RSV相关ARI的有效性为89%（95%CI，79% - 94%），对RSV相关住院的有效性为93%（95%CI，82% - 97%）。在229个测序样本中，根据婴儿nirsevimab接受状态，nirsevimab结合位点突变无差异。
该分析记录了美国幼儿中因医学就诊的RSV相关ARI持续存在的高负担。未来季节增加预防产品的覆盖范围并实现公平覆盖可能对公共卫生产生重大影响。
