Background Nirsevimab is an extended half-life, highly potent neutralizing monoclonal antibody against the respiratory syncytial virus (RSV) fusion protein, with efficacy in preventing RSV-associated medically attended (MA) lower respiratory tract infection (LRTI) in infants and medically vulnerable children (aged ≤24 months). This post-hoc exploratory analysis examined the incidence of LRTI from RSV and other respiratory pathogens during a 2:1 randomized, double-blind, placebo-controlled, phase 3 study of nirsevimab, in healthy-term and late-preterm (i.e. gestational age ≥35 weeks) infants entering their first RSV season (MELODY). Methods 3012 participants were randomized to nirsevimab (n = 2009) or placebo (n = 1003). Nasopharyngeal swabs were collected from infants presenting with an LRTI and tested for 22 different respiratory pathogens using the BioFire® Respiratory 2.1 Panel. Incidence of RSV and non-RSV MA-LRTIs through Day 511 and LRTI severity per the ReSViNET scale were assessed. Results 852 nasopharyngeal swabs were collected from 561 participants through Day 511: 519 swabs from 337 nirsevimab participants and 333 swabs from 224 placebo participants. RSV and non-RSV infections were detected in 193/852 (22.7%) and 551/852 (64.7%) swabs, respectively. RSV infection rates were lower with nirsevimab compared with placebo, including RSV-rhinovirus/enterovirus coinfections. Rates of other viral infections were similar between study arms. Approximately 70% of single RSV infections and RSV coinfections were adjudicated as mild, and 26.2% of single RSV infections and 24.5% of RSV coinfections required hospitalization. Conclusions Nirsevimab protected against RSV single and coinfections, with no evidence of replacement of RSV with other respiratory viruses. Trial Registration ClinicalTrials.gov NCT03979313.

中文翻译：

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呼吸道合胞病毒单克隆抗体 nirsevimab 免疫接种后下呼吸道感染与安慰剂相比：来自 3 期随机临床试验 （MELODY） 的分析


背景 Nirsevimab 是一种针对呼吸道合胞病毒 （RSV） 融合蛋白的延长半衰期、高效的中和单克隆抗体，可有效预防婴儿和医学上易感儿童 （≤24 个月） 的 RSV 相关就医 （MA） 下呼吸道感染 （LRTI）。这项事后探索性分析在 nirsevimab 的 2：1 随机、双盲、安慰剂对照、3 期研究中检查了 RSV 和其他呼吸道病原体导致 LRTI 的发生率，在健康足月和晚期早产儿（即胎龄 ≥35 周）进入第一个 RSV 季节 （MELODY） 的婴儿。方法 将 3012 名参与者随机分配到 nirsevimab （n = 2009） 或安慰剂组 （n = 1003）。从患有 LRTI 的婴儿中收集鼻咽拭子，并使用 BioFire® Respiratory 2.1 Panel 检测 22 种不同的呼吸道病原体。根据 ReSViNET 量表评估第 511 天 RSV 和非 RSV MA-LRTI 的发生率和 LRTI 严重程度。结果 截至第 511 天，从 561 名参与者中收集了 852 份鼻咽拭子： 来自 337 名 nirsevimab 参与者的 519 份拭子，来自 333 名安慰剂参与者的 224 份拭子。在 193/852 （22.7%） 和 551/852 （64.7%） 拭子中分别检测到 RSV 和非 RSV 感染。与安慰剂相比，nirsevimab 的 RSV 感染率较低，包括 RSV-鼻病毒/肠道病毒混合感染。研究组之间其他病毒感染的发生率相似。大约 70% 的单一 RSV 感染和 RSV 合并感染被判定为轻度，26.2% 的单一 RSV 感染和 24.5% 的 RSV 合并感染需要住院治疗。结论 Nirsevimab 可预防 RSV 单一感染和混合感染，没有证据表明 RSV 被其他呼吸道病毒替代。 试验注册 ClinicalTrials.gov NCT03979313。