Chalupka Alena, Riedmann Uwe, Richter Lukas, Chakeri Ali, El-Khatib Ziad, Sprenger Martin, Theiler-Schwetz Verena, Trummer Christian, Willeit Peter, Schennach Harald, Benka Bernhard, Werber Dirk, Høeg Tracy Beth, Ioannidis John P A, Pilz Stefan
Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
Institute for Surveillance and Infectious Disease Epidemiology, Austrian Agency for Health and Food Safety, Vienna, Austria.
Open Forum Infect Dis. 2024 Sep 19;11(10):ofae547. doi: 10.1093/ofid/ofae547. eCollection 2024 Oct.
We aimed to evaluate the effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations in previously SARS-CoV-2-infected adults in the general population of Austria during the Delta wave and with extended follow-up.
In a nationwide retrospective cohort study, we calculated age-, sex-, and nursing home residency-adjusted Cox proportional hazard ratios (HRs) of coronavirus disease 2019 (COVID-19) deaths, SARS-CoV-2 infections, and non-COVID-19 deaths from 1 October to 31 December 2021, and secondarily with extended follow-up to 30 June 2022. Relative vaccine effectiveness (rVE) is rVE = (1 - HR) × 100.
Among 494 646 previously infected adults, 169 543 had received 2 vaccine doses, 133 567 had received 1 dose, and 190 275 were unvaccinated at baseline. We recorded 17 COVID-19 deaths (6 vaccinated, 11 unvaccinated) and 8209 SARS-CoV-2 infections. Absolute risk of COVID-19 deaths was 0.003%. rVE estimates for COVID-19 deaths and reinfections exceeded 75% until the end of 2021 but decreased substantially with extended follow-up. The risk of non-COVID-19 death was lower in those vaccinated versus unvaccinated.
First and second SARS-CoV-2 vaccine doses appear effective in the short-term, but with diminishing effectiveness over time. The extremely low COVID-19 mortality, regardless of vaccination, indicates strong protection of previous infection against COVID-19 death. Lower non-COVID-19 mortality in the vaccinated population might suggest a healthy vaccinee bias.
我们旨在评估在奥地利普通人群中，于德尔塔变异株流行期间以及延长随访期内，严重急性呼吸综合征冠状病毒2（SARS-CoV-2）疫苗接种对既往感染过SARS-CoV-2的成年人的有效性。
在一项全国性回顾性队列研究中，我们计算了2021年10月1日至12月31日期间，经年龄、性别和养老院居住情况调整后的新型冠状病毒肺炎（COVID-19）死亡、SARS-CoV-2感染和非COVID-19死亡的Cox比例风险比（HRs），并进行了延长至2022年6月30日的随访。相对疫苗有效性（rVE）为rVE = (1 - HR) × 100。
在494646名既往感染过的成年人中，169543人接种了2剂疫苗，133567人接种了1剂疫苗，190275人在基线时未接种疫苗。我们记录了17例COVID-19死亡病例（6例接种疫苗，11例未接种疫苗）和8209例SARS-CoV-2感染病例。COVID-19死亡的绝对风险为0.003%。截至2021年底，COVID-19死亡和再感染的rVE估计值超过75%，但随着随访期延长大幅下降。接种疫苗者的非COVID-19死亡风险低于未接种疫苗者。
SARS-CoV-2疫苗的第一剂和第二剂在短期内似乎有效，但随着时间推移有效性逐渐降低。无论是否接种疫苗，COVID-19死亡率极低，表明既往感染对COVID-19死亡有强大的保护作用。接种疫苗人群中非COVID-19死亡率较低可能提示存在健康的疫苗接种者偏倚。
