Effectiveness of COVID-19 vaccines against hospitalisation, death and infection over time in Aotearoa New Zealand: a retrospective cohort study.

IF 1.2 Q2 MEDICINE, GENERAL & INTERNAL

NEW ZEALAND MEDICAL JOURNAL Pub Date : 2024-09-06 DOI:10.26635/6965.6573

James F Mbinta, Andrew A Sporle, Jan Sheppard, Aliitasi Su'a-Tavila, Binh P Nguyen, Nigel French, Colin R Simpson

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Abstract

Aims: This study aimed to evaluate the effectiveness of COVID-19 vaccines in preventing COVID-19 outcomes when the Omicron variant was predominant in Aotearoa New Zealand.

Methods: We conducted a retrospective cohort study using routinely available data (8 December 2020-28 February 2023). We evaluated the vaccine effectiveness (VE) of COVID-19 vaccines using the Cox proportional-hazards model, adjusting for covariates.

Results: The VE against COVID-19 hospitalisation (VEH) for the second booster dose compared to no vaccination was found to be 81.8% (95% confidence interval [95% CI]: 73.6-87.5) after 1 month post-vaccination. After 4 months, VEH was 72.2% (95% CI: 58.5-81.4), and after 6 months VEH was 49.0% (95% CI: 7.9-71.8). Similarly, VEH decreased after the first booster dose (1-month VEH=81.6% [95% CI: 75.6-86.1]; 2 months VEH=74.7% [95% CI: 68.2-79.9]; and 6 months VEH=57.4% [95% CI: 45.8-66.6]). VE against COVID-19 death (VED) was 92.9% (95% CI: 82.1-97.2) 2 months after the first booster vaccination, with VED being sustained until months 5 and 6 (VED=87.2%; 95% CI: 67.4-94.9). The VE after the second dose of the vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (VEI) (real-time polymerase chain reaction [RT-PCR]) was sustained at 5 months post-vaccination (40.6%; 95% CI: 25.6-52.5).

Conclusion: We provide a comprehensive quantification of both VE and VE waning. These findings can guide policymakers to help evaluate the COVID-19 vaccination programme and minimise the effect of future COVID-19 in Aotearoa New Zealand.

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在新西兰奥特亚罗瓦，COVID-19 疫苗在预防住院、死亡和感染方面的效果：一项回顾性队列研究。

目的：本研究旨在评估当新西兰奥特亚罗瓦地区以Omicron变异体为主时，COVID-19疫苗在预防COVID-19结果方面的有效性：我们利用常规可用数据（2020 年 12 月 8 日至 2023 年 2 月 28 日）开展了一项回顾性队列研究。我们使用 Cox 比例危险模型评估了 COVID-19 疫苗的有效性（VE），并对协变量进行了调整：结果：接种后 1 个月，与未接种疫苗相比，接种第二针加强剂的 COVID-19 住院有效率（VEH）为 81.8%（95% 置信区间 [95%CI]：73.6-87.5）。4 个月后，VEH 为 72.2%（95% 置信区间：58.5-81.4），6 个月后，VEH 为 49.0%（95% 置信区间：7.9-71.8）。同样，首次加强剂量后，VEH 也有所下降（1 个月 VEH=81.6% [95% CI：75.6-86.1]；2 个月 VEH=74.7% [95% CI：68.2-79.9]；6 个月 VEH=57.4% [95% CI：45.8-66.6]）。第一次加强免疫 2 个月后，COVID-19 死亡 VE 为 92.9% (95% CI: 82.1-97.2)，VED 持续到第 5 个月和第 6 个月 (VED=87.2%; 95% CI: 67.4-94.9)。接种第二剂疫苗预防严重急性呼吸系统综合征冠状病毒 2（SARS-CoV-2）感染（VEI）（实时聚合酶链反应 [RT-PCR]）后的 VE 持续到接种后 5 个月（40.6%；95% CI：25.6-52.5）：我们对 VE 和 VE 减弱进行了全面量化。这些发现可为政策制定者提供指导，帮助他们评估 COVID-19 疫苗接种计划，并将 COVID-19 未来在新西兰奥特亚罗瓦的影响降至最低。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

NEW ZEALAND MEDICAL JOURNAL MEDICINE, GENERAL & INTERNAL-

CiteScore

2.30

自引率

23.50%

发文量

229