Abstract：
BACKGROUND: In Catalonia, infants under 6 months old were eligible to receive nirsevimab, a novel monoclonal antibody against respiratory syncytial virus (RSV). We aimed to analyse nirsevimab\'s effectiveness across primary and hospital care outcomes.
METHODS: Retrospective cohort study from 1 October 2023 to 31 January 2024, including all infants born between April and September 2023. We established two cohorts based on nirsevimab administration (immunised and non-immunised). We followed individuals until the earliest moment of an outcome-RSV infection, primary care attended bronchiolitis and pneumonia, hospital emergency visits due to bronchiolitis, hospital admission or intensive care unit (ICU) admission due to RSV bronchiolitis-death or the end of the study. We used the Kaplan-Meier estimator and fitted Cox regression models using a calendar time scale to estimate HRs and their 95% CIs.
RESULTS: Among 26 525 infants, a dose of nirsevimab led to an adjusted HR for hospital admission due to RSV bronchiolitis of 0.124 (95% CI: 0.086 to 0.179) and an adjusted HR for ICU admission of 0.099 (95% CI: 0.041 to 0.237). Additionally, the adjusted HRs observed for emergency visits were 0.446 (95% CI: 0.385 to 0.516) and 0.393 (95% CI: 0.203 to 0.758) for viral pneumonia, 0.519 (95% CI: 0.467 to 0.576) for bronchiolitis attended in primary care and 0.311 (95% CI: 0.200 to 0.483) for RSV infection.
CONCLUSIONS: We demonstrated nirsevimab\'s effectiveness with reductions of 87.6% and 90.1% in hospital and ICU admissions, respectively. These findings offer crucial guidance for public health authorities in implementing RSV immunisation campaigns.
METHODS: Retrospective cohort study from 1 October 2023 to 31 January 2024, including all infants born between April and September 2023. We established two cohorts based on nirsevimab administration (immunised and non-immunised). We followed individuals until the earliest moment of an outcome-RSV infection, primary care attended bronchiolitis and pneumonia, hospital emergency visits due to bronchiolitis, hospital admission or intensive care unit (ICU) admission due to RSV bronchiolitis-death or the end of the study. We used the Kaplan-Meier estimator and fitted Cox regression models using a calendar time scale to estimate HRs and their 95% CIs.
RESULTS: Among 26 525 infants, a dose of nirsevimab led to an adjusted HR for hospital admission due to RSV bronchiolitis of 0.124 (95% CI: 0.086 to 0.179) and an adjusted HR for ICU admission of 0.099 (95% CI: 0.041 to 0.237). Additionally, the adjusted HRs observed for emergency visits were 0.446 (95% CI: 0.385 to 0.516) and 0.393 (95% CI: 0.203 to 0.758) for viral pneumonia, 0.519 (95% CI: 0.467 to 0.576) for bronchiolitis attended in primary care and 0.311 (95% CI: 0.200 to 0.483) for RSV infection.
CONCLUSIONS: We demonstrated nirsevimab\'s effectiveness with reductions of 87.6% and 90.1% in hospital and ICU admissions, respectively. These findings offer crucial guidance for public health authorities in implementing RSV immunisation campaigns.
摘要：
背景：在加泰罗尼亚，6个月以下的婴儿有资格接受nirsevimab，一种针对呼吸道合胞病毒（RSV）的新型单克隆抗体。我们旨在分析nirsevimab在基层和医院护理结果中的有效性。
方法：回顾性队列研究，从2023年10月1日至2024年1月31日，包括2023年4月至9月出生的所有婴儿。我们基于nirsevimab给药建立了两个队列(免疫和非免疫)。我们跟踪个体，直到结果RSV感染的最早时刻，初级护理包括毛细支气管炎和肺炎，由于毛细支气管炎，医院急诊就诊，因RSV毛细支气管炎死亡或研究结束而入院或重症监护病房（ICU）。我们使用Kaplan-Meier估计器，并使用日历时间尺度拟合Cox回归模型来估计HR及其95%CI。
结果：在26525名婴儿中，一定剂量的nirsevimab导致因RSV细支气管炎入院时的校正HR为0.124(95%CI:0.086~0.179),ICU入院时的校正HR为0.099(95%CI:0.041~0.237).此外,对于病毒性肺炎，急诊就诊观察到的调整后的HR为0.446（95％CI：0.385至0.516）和0.393（95％CI：0.203至0.758），初级保健治疗的细支气管炎为0.519（95％CI：0.467至0.576），RSV感染为0.311（95％CI：0.200至0.483）。
结论：我们证明了nirsevimab的有效性，在住院和ICU住院患者中分别减少了87.6％和90.1％，分别。这些发现为公共卫生当局实施RSV免疫运动提供了重要指导。
方法：回顾性队列研究，从2023年10月1日至2024年1月31日，包括2023年4月至9月出生的所有婴儿。我们基于nirsevimab给药建立了两个队列(免疫和非免疫)。我们跟踪个体，直到结果RSV感染的最早时刻，初级护理包括毛细支气管炎和肺炎，由于毛细支气管炎，医院急诊就诊，因RSV毛细支气管炎死亡或研究结束而入院或重症监护病房（ICU）。我们使用Kaplan-Meier估计器，并使用日历时间尺度拟合Cox回归模型来估计HR及其95%CI。
结果：在26525名婴儿中，一定剂量的nirsevimab导致因RSV细支气管炎入院时的校正HR为0.124(95%CI:0.086~0.179),ICU入院时的校正HR为0.099(95%CI:0.041~0.237).此外,对于病毒性肺炎，急诊就诊观察到的调整后的HR为0.446（95％CI：0.385至0.516）和0.393（95％CI：0.203至0.758），初级保健治疗的细支气管炎为0.519（95％CI：0.467至0.576），RSV感染为0.311（95％CI：0.200至0.483）。
结论：我们证明了nirsevimab的有效性，在住院和ICU住院患者中分别减少了87.6％和90.1％，分别。这些发现为公共卫生当局实施RSV免疫运动提供了重要指导。
