Public Health Risk Science Division, National Microbiology Laboratory, Public Health Agency of Canada, Guelph, ON, Canada.
Department of Population Medicine, University of Guelph, Guelph, ON, Canada.
Epidemiol Infect. 2023 Aug 18;151:e145. doi: 10.1017/S0950268823001279.
Post COVID-19 condition (PCC) refers to persistent or recurring symptoms (>8 weeks) occurring ≤12 weeks following acute COVID-19. The objective of this systematic review was to assess the evidence on the risk of PCC with vaccination before or after COVID-19 or after developing PCC, and the safety of vaccination among those already experiencing PCC. A search was conducted up to 13 December 2022 and standard systematic review methodology was followed. Thirty-one observational studies were included. There is moderate confidence that two doses of vaccine given pre-infection reduced the odds of PCC (pooled OR (pOR) 0.67, 95% CI 0.60-0.74, I2 = 59.9%), but low confidence that one dose may not reduce the odds (pOR 0.64, 95% CI 0.31#x2013;1.31, I2 = 99.2%), and the evidence is very uncertain about the effect of three doses (pOR 0.45, 95% CI 0.10#x2013;1.99, I2 = 30.9%). One of three studies suggested vaccination shortly after COVID-19 may offer additional protection from developing PCC compared to unvaccinated individuals, but this evidence was very uncertain. For those with PCC, vaccination was not associated with worsening PCC symptoms (10 studies) and appears safe (3 studies), but it is unclear if vaccination may change established PCC symptoms.
新冠后状况（PCC）是指急性新冠后 8 周内出现的持续或复发症状（>8 周）。本系统评价的目的是评估接种疫苗预防新冠前后或发生 PCC 后出现 PCC 的风险，以及已经患有 PCC 的人接种疫苗的安全性。搜索截止到 2022 年 12 月 13 日，并遵循了标准的系统评价方法。共纳入 31 项观察性研究。有中等置信度表明，感染前接种两剂疫苗可降低 PCC 的几率（汇总比值比（pOR）0.67，95%置信区间 0.60-0.74，I2=59.9%），但低置信度表明一剂可能不会降低几率（pOR 0.64，95%置信区间 0.31-1.31，I2=99.2%），且三剂的效果证据非常不确定（pOR 0.45，95%置信区间 0.10-1.99，I2=30.9%）。三项研究中有一项表明，与未接种疫苗的个体相比，新冠后不久接种疫苗可能会提供额外的保护，防止发生 PCC，但这一证据非常不确定。对于患有 PCC 的人，接种疫苗与 PCC 症状恶化无关（10 项研究），且似乎安全（3 项研究），但不清楚接种疫苗是否会改变已确立的 PCC 症状。
