Galicia (Spain) was one of the first regions worldwide to incorporate nirsevimab for universal respiratory syncytial virus (RSV) prophylaxis in infants into its immunisation programme. The NIRSE-GAL longitudinal population-based study aimed to assess nirsevimab effectiveness in preventing hospitalisations (ie, admittance to hospital). The 2023–24 immunisation campaign with nirsevimab in Galicia began on Sept 25, 2023, and concluded on March 31, 2024. The campaign targeted three groups: infants born during the campaign (seasonal group), infants younger than 6 months at the start of the campaign (catch-up group), and infants aged 6–24 months with high-risk factors at the start of the campaign (high-risk group). Infants in the seasonal group were offered immunisation on the first day of life before discharge from hospital. Infants in the catch-up and high-risk groups received electronic appointments to attend a public hospital or health-care centre for nirsevimab administration. For this interim analysis, we used data collected from Sept 25 to Dec 31, 2023, from children born up to Dec 15, 2023. Data were retrieved from public health registries. Nirsevimab effectiveness in preventing RSV-associated lower respiratory tract infection (LRTI) hospitalisations; severe RSV-related LRTI requiring intensive care unit admission, mechanical ventilation, or oxygen support; all-cause LRTI hospitalisations; and all-cause hospitalisations was estimated using adjusted Poisson regression models. Data from five past RSV seasons (2016–17, 2017–18, 2018–19, 2019–20, and 2022–23), excluding the COVID-19 pandemic period, were used to estimate the number of RSV-related LRTI hospitalisations averted along with its IQR. The number needed to immunise to avoid one case in the 2023–24 season was then estimated from the averted cases. Nirsevimab safety was routinely monitored. The NIRSE-GAL study protocol was registered on (), and follow-up of participants is ongoing. 9408 (91·7%) of 10 259 eligible infants in the seasonal and catch-up groups received nirsevimab, including 6220 (89·9%) of 6919 in the catch-up group and 3188 (95·4%) of 3340 in the seasonal group. 360 in the high-risk group were offered nirsevimab, 348 (97%) of whom received it. Only infants in the seasonal and catch-up groups were included in analyses to estimate nirsevimab effectiveness and impact because there were too few events in the high-risk group. In the catch-up and seasonal groups combined, 30 (0·3%) of 9408 infants who received nirsevimab and 16 (1·9%) of 851 who did not receive nirsevimab were hospitalised for RSV-related LRTI, corresponding to an effectiveness of 82·0% (95% CI 65·6–90·2). Effectiveness was 86·9% (69·1–94·2) against severe RSV-related LRTI requiring oxygen support, 69·2% (55·9–78·0) against all-cause LRTI hospitalisations, and 66·2% (56·0–73·7) against all-cause hospitalisations. Nirsevimab effectiveness against other endpoints of severe RSV-related LRTI could not be estimated because of too few events. RSV-related LRTI hospitalisations were reduced by 89·8% (IQR 87·5–90·3), and the number needed to immunise to avoid one RSV-related LRTI hospitalisation was 25 (IQR 24–32). No severe adverse events related to nirsevimab were registered. Nirsevimab substantially reduced infant hospitalisations for RSV-associated LRTI, severe RSV-associated LRTI requiring oxygen, and all-cause LRTI when given in real-world conditions. These findings offer policy makers and health authorities robust, real-world, population-based evidence to guide the development of strategies for RSV prevention. Sanofi and AstraZeneca. For the Spanish translation of the abstract see Supplementary Materials section.

中文翻译：

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西班牙加利西亚婴儿使用尼瑞单抗普遍预防呼吸道合胞病毒住院的有效性和影响：基于人群的纵向研究的初步结果


加利西亚（西班牙）是全球首批将 nirsevimab 用于婴儿呼吸道合胞病毒 (RSV) 预防的地区之一纳入其免疫计划。 NIRSE-GAL 基于人群的纵向研究旨在评估 nirsevimab 在预防住院（即入院）方面的有效性。加利西亚的 2023-24 年 nirsevimab 免疫运动于 2023 年 9 月 25 日开始，并于 2024 年 3 月 31 日结束。该运动针对三个群体：运动期间出生的婴儿（季节性组）、运动开始时 6 个月以下的婴儿。活动期间（补习组）和活动开始时具有高风险因素的 6-24 个月婴儿（高风险组）。季节性组的婴儿在出生第一天出院前接受了免疫接种。追赶组和高危组的婴儿接受电子预约，前往公立医院或医疗中心接受 nirsevimab 治疗。在本次中期分析中，我们使用了 2023 年 9 月 25 日至 12 月 31 日收集的数据，这些数据来自 2023 年 12 月 15 日之前出生的儿童。数据是从公共卫生登记处检索的。 Nirsevimab 在预防 RSV 相关下呼吸道感染 (LRTI) 住院方面的有效性；严重的 RSV 相关 LRTI，需要入住重症监护病房、机械通气或氧气支持；全因 LRTI 住院治疗；并使用调整后的泊松回归模型估计全因住院率。使用过去五个 RSV 季节（2016-17、2017-18、2018-19、2019-20 和 2022-23）的数据（不包括 COVID-19 大流行期间）来估计避免的 RSV 相关 LRTI 住院人数及其 IQR。 然后根据避免的病例估算出 2023-24 赛季避免出现一例病例所需的免疫接种人数。定期监测 Nirsevimab 的安全性。 NIRSE-GAL 研究方案已于 () 注册，对参与者的随访正在进行中。季节性组和追赶组中 10 259 名符合条件的婴儿中，有 9408 名 (91·7%) 接受了 nirsevimab 治疗，其中追赶组中 6919 名婴儿中有 6220 名 (89·9%) 接受治疗，而季节性组和追赶组中 3340 名婴儿中有 3188 名 (95·4%) 接受了 nirsevimab 治疗。季节性组。高风险组中的 360 人接受了 nirsevimab，其中 348 人（97%）接受了治疗。仅将季节性组和追赶组中的婴儿纳入分析中，以估计 nirsevimab 的有效性和影响，因为高风险组中的事件太少。在追赶组和季节性组中，接受 nirsevimab 治疗的 9408 名婴儿中有 30 名 (0·3%) 以及未接受 nirsevimab 治疗的 851 名婴儿中有 16 名 (1·9%) 因 RSV 相关 LRTI 住院，这与有效性相对应82·0% (95% CI 65·6–90·2)。对于需要氧气支持的严重 RSV 相关 LRTI 的有效性为 86·9% (69·1–94·2)，对于全因 LRTI 住院的有效性为 69·2% (55·9–78·0)，以及 66·2% (56·0–73·7) 反对因各种原因住院。由于事件太少，无法估计 Nirsevimab 针对严重 RSV 相关 LRTI 的其他终点的有效性。 RSV 相关 LRTI 住院率减少了 89·8% (IQR 87·5–90·3)，为避免一次 RSV 相关 LRTI 住院而需要进行免疫的人数为 25 (IQR 24–32)。没有记录到与 nirsevimab 相关的严重不良事件。 Nirsevimab 显着减少了婴儿因 RSV 相关 LRTI、需要吸氧的严重 RSV 相关 LRTI 和全因 LRTI 在现实条件下住院的情况。 这些发现为政策制定者和卫生当局提供了强有力的、真实的、基于人群的证据，以指导制定 RSV 预防策略。赛诺菲和阿斯利康。有关摘要的西班牙语翻译，请参阅补充材料部分。