Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Region Västra Götaland, Department of Clinical Pharmacology, Sahlgrenska University Hospital, Gothenburg, Sweden.
BMJ. 2023 Nov 22;383:e076990. doi: 10.1136/bmj-2023-076990.
To investigate the effectiveness of primary covid-19 vaccination (first two doses and first booster dose within the recommended schedule) against post-covid-19 condition (PCC).
Population based cohort study.
Swedish Covid-19 Investigation for Future Insights-a Population Epidemiology Approach using Register Linkage (SCIFI-PEARL) project, a register based cohort study in Sweden.
All adults (≥18 years) with covid-19 first registered between 27 December 2020 and 9 February 2022 (n=589 722) in the two largest regions of Sweden. Individuals were followed from a first infection until death, emigration, vaccination, reinfection, a PCC diagnosis (ICD-10 diagnosis code U09.9), or end of follow-up (30 November 2022), whichever came first. Individuals who had received at least one dose of a covid-19 vaccine before infection were considered vaccinated.
The primary outcome was a clinical diagnosis of PCC. Vaccine effectiveness against PCC was estimated using Cox regressions adjusted for age, sex, comorbidities (diabetes and cardiovascular, respiratory, and psychiatric disease), number of healthcare contacts during 2019, socioeconomic factors, and dominant virus variant at time of infection.
Of 299 692 vaccinated individuals with covid-19, 1201 (0.4%) had a diagnosis of PCC during follow-up, compared with 4118 (1.4%) of 290 030 unvaccinated individuals. Covid-19 vaccination with any number of doses before infection was associated with a reduced risk of PCC (adjusted hazard ratio 0.42, 95% confidence interval 0.38 to 0.46), with a vaccine effectiveness of 58%. Of the vaccinated individuals, 21 111 received one dose only, 205 650 received two doses, and 72 931 received three or more doses. Vaccine effectiveness against PCC for one dose, two doses, and three or more doses was 21%, 59%, and 73%, respectively.
The results of this study suggest a strong association between covid-19 vaccination before infection and reduced risk of receiving a diagnosis of PCC. The findings highlight the importance of primary vaccination against covid-19 to reduce the population burden of PCC.
研究初级新冠病毒疫苗接种（按建议时间表接种前两剂和第一剂加强针）对新冠后疾病（PCC）的效果。
基于人群的队列研究。
瑞典新冠病毒未来洞察的基础研究-使用登记链接的人群流行病学方法（SCIFI-PEARL）项目，在瑞典进行的一项基于登记的队列研究。
所有在 2020 年 12 月 27 日至 2022 年 2 月 9 日期间首次登记的新冠病毒感染（≥18 岁）的成年人（n=589722）在瑞典的两个最大地区。从首次感染开始，对个体进行随访，直至死亡、移民、接种疫苗、再次感染、PCC 诊断（ICD-10 诊断代码 U09.9）或随访结束（2022 年 11 月 30 日），以先发生者为准。在感染前至少接种过一剂新冠病毒疫苗的个体被认为是已接种疫苗的个体。
主要结局是 PCC 的临床诊断。使用 Cox 回归模型，根据年龄、性别、合并症（糖尿病和心血管、呼吸和精神疾病）、2019 年期间的医疗保健接触次数、社会经济因素以及感染时的主要病毒变体，对 PCC 疫苗有效性进行了调整。
在 299692 名接种过新冠病毒疫苗的有记录的个体中，有 1201 例（0.4%）在随访期间被诊断为 PCC，而在 290030 名未接种疫苗的个体中，有 4118 例（1.4%）被诊断为 PCC。在感染前接种任何剂量的新冠病毒疫苗都与 PCC 风险降低相关（调整后的危险比 0.42，95%置信区间 0.38 至 0.46），疫苗有效性为 58%。在接种疫苗的个体中，21111 人仅接种了一剂，205650 人接种了两剂，72931 人接种了三剂或更多剂。一剂、两剂和三剂或更多剂的 PCC 疫苗有效性分别为 21%、59%和 73%。
这项研究的结果表明，在感染前接种新冠病毒疫苗与降低 PCC 诊断风险之间存在很强的关联。研究结果强调了初级新冠病毒疫苗接种对降低 PCC 人群负担的重要性。
