Department of Primary Care and Population Health, University of Nicosia Medical School, Nicosia, Cyprus.
School of Medicine, European University, Nicosia, Cyprus.
Public Health. 2022 Mar;204:84-86. doi: 10.1016/j.puhe.2022.01.008. Epub 2022 Jan 20.
We explored the effectiveness of COVID-19 vaccines in preventing reinfection in the Republic of Cyprus.
This was a matched case-control study (1:2).
Cases were adults with a first episode of SARS-CoV-2 infection in 2020 and a second episode (i.e. reinfection) between June and August 2021. Controls were adults with only one infection episode in 2020 (i.e. not reinfected). Matching was performed by age, gender, and week of diagnosis for the first episode. The reinfection date of a case was applied to the matched controls for estimating full or partial vaccination status. Cases and controls were classified as unvaccinated, partially vaccinated (i.e. vaccination series not completed or final dose received ≤14 days before the reinfection date), or fully vaccinated (i.e. final dose received >14 days before the reinfection date). Conditional logistic regression was performed to calculate odds ratios and 95% confidence intervals for full or partial vaccination, against no vaccination, between controls and cases.
This study showed that controls were more likely to be vaccinated (odds ratio for full vaccination: 5.51, 95% confidence interval: 2.43-12.49) than cases.
This finding answers a pressing question of the public and supports the offer of vaccination to people with previous SARS-CoV-2 infection.
我们在塞浦路斯共和国探索了 COVID-19 疫苗在预防再次感染中的效果。
这是一项匹配的病例对照研究（1:2）。
病例为 2020 年首次发生 SARS-CoV-2 感染且 2021 年 6 月至 8 月间再次感染（即再次感染）的成年人。对照为 2020 年仅发生过一次感染（即未再次感染）的成年人。通过首次感染的年龄、性别和诊断周数进行匹配。将病例的再次感染日期应用于匹配对照，以估计完全或部分疫苗接种状态。病例和对照分为未接种、部分接种（即疫苗接种系列未完成或最后一剂在再次感染日期前 14 天内接种）或完全接种（即最后一剂在再次感染日期前 14 天以上接种）。采用条件逻辑回归计算对照和病例之间完全或部分接种相对于未接种的优势比及其 95%置信区间。
本研究表明，对照更有可能接种疫苗（完全接种的优势比：5.51，95%置信区间：2.43-12.49）。
这一发现回答了公众的一个紧迫问题，并支持向以前感染过 SARS-CoV-2 的人提供疫苗接种。
