Field Service, UK Health Security Agency (UKHSA), London SW1P 3JR, UK.
Immunisation and Countermeasures Division, UK Health Security Agency (UKHSA), London NW9 5EQ, UK.
Age Ageing. 2022 May 1;51(5). doi: 10.1093/ageing/afac115.
residents of long-term care facilities (LTCFs) are at high risk of adverse outcomes from SARS-CoV-2. We aimed to estimate the vaccine effectiveness (VE) of one and two doses of BNT162b2 and ChAdOx-1 against SARS CoV-2 infection and COVID-19-related death in residents of LTCFs.
this observational study used testing, vaccination and mortality data for LTCF residents aged ≥ 65 years who were regularly tested regardless of symptoms from 8 December 2020 to 30 September 2021 in England. Adjusted VE, calculated as one minus adjusted hazard ratio, was estimated using time-varying Cox proportional hazards models for infection and death within 28 days of positive test result. Vaccine status was defined by receipt of one or two doses of vaccine and assessed over a range of intervals.
of 197,885 LTCF residents, 47,087 (23.8%) had a positive test and 11,329 (5.8%) died within 28 days of a positive test during the study period. Relative to unvaccinated individuals, VE for infection was highest for ChAdOx-1 at 61% (40-74%) at 1-4 weeks and for BNT162b2 at 69% (52-80%) at 11-15 weeks following the second dose. Against death, VE was highest for ChAdOx-1 at 83% (58-94%) at 1-4 weeks and for BNT162b2 at 91% (75-97%) at 11-15 weeks following second dose.
compared with unvaccinated residents, vaccination with one dose of BNT162b2 or ChAdOx-1 provided moderate protection against infection and death in residents of LTCFs. Protection against death improved after two doses. However, some waning of protection over time was noted.
长期护理机构（LTCF）的居民感染 SARS-CoV-2 后出现不良后果的风险很高。我们旨在估计 BNT162b2 和 ChAdOx-1 对 LTCF 居民 SARS-CoV-2 感染和 COVID-19 相关死亡的一剂和两剂疫苗有效性（VE）。
这项观察性研究使用了 2020 年 12 月 8 日至 2021 年 9 月 30 日期间，年龄在 65 岁以上的经常接受检测（无论症状如何）的 LTCF 居民的检测、接种和死亡率数据。使用时间变化的 Cox 比例风险模型，根据 28 天内阳性检测结果内感染和死亡的调整后 VE，估计调整后的 VE，计算方法为 1 减去调整后的危险比。疫苗接种状态通过接种一剂或两剂疫苗来定义，并在一系列间隔内进行评估。
在 197885 名 LTCF 居民中，47087 人（23.8%）的检测结果呈阳性，在研究期间 11329 人（5.8%）在阳性检测结果后 28 天内死亡。与未接种疫苗的个体相比，ChAdOx-1 的感染 VE 最高，在第二剂后 1-4 周内为 61%（40-74%），而 BNT162b2 的感染 VE 最高，在第二剂后 11-15 周内为 69%（52-80%）。在死亡方面，ChAdOx-1 的 VE 最高，在 1-4 周内为 83%（58-94%），而 BNT162b2 的 VE 最高，在第二剂后 11-15 周内为 91%（75-97%）。
与未接种疫苗的居民相比，接种一剂 BNT162b2 或 ChAdOx-1 可对 LTCF 居民的感染和死亡提供中度保护。第二剂后，对死亡的保护作用有所提高。然而，随着时间的推移，保护作用出现了一些减弱。
