EPI-PHARE Scientific Interest Group in Epidemiology of Health Products (French National Agency for the Safety of Medicines and Health Products-ANSM, French National Health Insurance-CNAM), Saint-Denis, France.
Clinical Research and Innovation Department, Guadeloupe University Hospital Center, Les Abymes, Guadeloupe.
PLoS One. 2022 Sep 9;17(9):e0274309. doi: 10.1371/journal.pone.0274309. eCollection 2022.
Although several observational studies on the effectiveness of SARS-CoV-2 vaccination have been published, vaccination coverage by August, 3 2021, remained low in the French overseas territories, despite Martinique and Guadeloupe experiencing an unprecedented number of COVID-19-related hospitalizations. We aimed to determine the association between COVID-19 vaccination and severe COVID-19 in the French overseas territories.
The French National Health Data System was used to conduct a 1:1 matched-cohort study. For each individual receiving a first dose of BNT162b2, mRNA-1273, ChAdOx1 nCoV-19, or Ad26.COV2-S vaccine between December 27, 2020, and July 31, 2021, one unvaccinated individual was randomly selected and matched for year of birth, sex, and overseas territories on the date of vaccination. We estimated vaccine effectiveness against COVID-19-related hospitalization and in-hospital death after a full vaccination schedule, defined as ≥14 days after the second dose. Analyses were stratified according to the number of comorbidities.
276,778 vaccinated individuals had a double-dose vaccination during the follow-up period and were followed with their paired unvaccinated control. The average age was 50 years and 53% were women. During a median 77 days of follow-up from day 14 after the second injection, 96 COVID-19-related hospitalizations occurred among vaccinated individuals and 1,465 among their unvaccinated counterparts. Overall, vaccine effectiveness against hospitalization was 94% (95%CI [93-95]) and exceeded 90% in each overseas territory, except Mayotte. The results were similar looking specifically at hospitalizations between July 15 and September 30, 2021. Vaccine effectiveness against in-hospital death was similar (94% [95%CI 91-96]). The risk of COVID-19-related hospitalization increased with the number of comorbidities, especially among vaccinated individuals.
In conclusion, vaccination has a major effect in reducing the risk of severe Covid-19 in the French overseas territories. The risk of COVID-19-hospitalization was very low among vaccinated individuals, especially in the absence of comorbidities. These results aim to increase confidence in vaccine effectiveness in overseas territories in hope of achieving better vaccination coverage.
重要性：尽管已经发表了几项关于 SARS-CoV-2 疫苗有效性的观察性研究，但截至 2021 年 8 月，法国海外领地的疫苗接种覆盖率仍然很低，尽管马提尼克岛和瓜德罗普岛经历了前所未有的与 COVID-19 相关的住院人数。我们旨在确定法国海外领地 COVID-19 疫苗接种与严重 COVID-19 之间的关联。
方法：利用法国国家卫生数据系统进行了 1:1 匹配队列研究。对于 2020 年 12 月 27 日至 2021 年 7 月 31 日期间接受 BNT162b2、mRNA-1273、ChAdOx1 nCoV-19 或 Ad26.COV2-S 疫苗第一剂的每一位个体，随机选择一位未接种疫苗的个体，并根据接种日期在出生年份、性别和海外领地进行匹配。我们估计了完全接种疫苗后（第二剂后≥14 天）与 COVID-19 相关的住院和住院死亡的疫苗有效性。分析根据合并症的数量进行分层。
结果：在随访期间，276778 名接种疫苗的个体接受了双剂量接种，并与配对的未接种疫苗的对照组一起随访。平均年龄为 50 岁，53%为女性。在从第二针后第 14 天开始的 77 天中位随访期间，接种疫苗的个体中有 96 例 COVID-19 相关住院，而未接种疫苗的个体中有 1465 例。总体而言，疫苗对住院的有效性为 94%（95%CI [93-95]），除马约特岛外，每个海外领地的有效性均超过 90%。在 2021 年 7 月 15 日至 9 月 30 日期间，专门观察住院情况的结果类似。疫苗对住院死亡的有效性相似（94%[95%CI 91-96]）。COVID-19 相关住院的风险随着合并症数量的增加而增加，尤其是在接种疫苗的个体中。
结论和相关性：总之，疫苗接种在降低法国海外领地严重 COVID-19 风险方面具有重大影响。接种疫苗的个体 COVID-19 住院风险非常低，尤其是在没有合并症的情况下。这些结果旨在增强对海外领地疫苗有效性的信心，以期实现更好的疫苗接种覆盖率。
