BACKGROUND: We aimed to evaluate the association between coronavirus disease 2019 (COVID-19) vaccination and the risk of stroke. METHOD: We conducted a systematic meta-analysis of studies published until December 24, 2022, using PubMed and the Cochrane database; real-world studies using cohort, self-controlled case series (SCCS), and case-crossover study (CCOS) designs were identified to evaluate the incidence risk ratios (IRRs) and 95% confidence intervals (CIs) of ischemic stroke (IS), hemorrhagic stroke (HS), and cerebral venous sinus thrombosis (CVST) following COVID-19 vaccination. Random-effects meta-analyses were performed to pool the risks of IS and HS among subpopulations categorized by vaccine type, dose, age, and sex. Sensitivity analysis was performed after stratification by defined risk periods. RESULTS: Fourteen observational studies involving 79,918,904 individuals were included. Cohort studies showed decreased risks of IS (IRR [95% CI], 0.82 [0.75-0.90]) and HS (IRR [95% CI], 0.75 [0.67-0.85]) post-vaccination, but no association with CVST was found (IRR [95% CI], 1.18 [0.70-1.98]). SCCS identified increased risks 1-21 days (IRR [95% CI]IS, 1.05 [1.00-1.10]; IRR [95% CI]HS, 1.16 [1.06-1.26]) or 1-28 days (IRR [95% CI]IS, 1.04 [1.00-1.08]; IRR [95% CI]HS, 1.37 [1.15-1.64]) post-vaccination, similar to CVST (IRR [95% CI], 1.58 [1.08-2.32]). A CCOS reported an increased risk of CVST after vaccination using ChAdOx1 (IRR [95% CI], 2.9 [1.1-7.2]). DISCUSSION: Although different study designs yielded inconsistent findings, considering the relatively low background incidence of stroke and benefits of vaccination, even a potentially increased risk of stroke post-vaccination should not justify vaccine hesitancy.
- Adolescents
- Adults
- Older adults
- Vaccine/vaccination
- COVID-19
- Safety
