Pre-infection vaccination linked to lower cardiovascular and cerebrovascular event risks in SARS-CoV-2 infected individuals

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medRxiv Published May 23, 2026 Medically reviewed May 23, 2026 Study authors: Heymans, S.; Heidecker, B.; Marjenberg, Z.; Green, R.; Pliakas, T.; Lip, G. Y. H.; Lüscher, T. F.; … DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider pre-infection vaccination as associated with lower risks for various cardiovascular events in infected individuals.

This systematic review and meta-analysis evaluated the impact of pre-infection COVID-19 vaccination on cardiovascular and cerebrovascular outcomes among individuals with SARS-CoV-2 infection. Data were drawn from twenty-three studies, with ten included in the meta-analyses, spanning pre- and post-Omicron eras. The primary outcome assessed was a composite of cardiovascular and cerebrovascular events, with secondary outcomes including stroke, acute coronary syndrome, arrhythmias, venous thromboembolism, and heart failure.

The analysis demonstrated that vaccinated individuals experienced significantly reduced risks for the composite cardiovascular and cerebrovascular events compared to unvaccinated individuals. This protective association extended to specific conditions such as stroke, acute coronary syndrome, arrhythmias, and venous thromboembolism. In contrast, the data did not show a statistically significant reduction in the risk of heart failure for the vaccinated group.

The authors note that the study design relies on observational data, meaning the findings represent associations rather than definitive proof of causation. No adverse events or tolerability issues were reported in the safety analysis. The authors suggest that these results support the role of vaccination within broader prevention strategies for individuals with SARS-CoV-2 infection, while acknowledging the inherent limitations of observational research.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedMay 2026

View Original Abstract ↓

Background and Aims SARS-CoV-2 infection is associated with an increased risk of cardiovascular, cerebrovascular and venous thromboembolism events. We aimed to assess the impact of COVID-19 vaccination prior to SARS-CoV-2 infection on the risk of these events post-infection. Methods Embase and MEDLINE were searched from January 2021 to 11 September 2025, supplemented by citation searching. Observational studies were included if they reported risks of cardiovascular, cerebrovascular, or venous thromboembolic events after SARS-CoV-2 infection between different vaccination groups (e.g. unvaccinated, vaccinated, or booster vaccinated), or reported risk of events after SARS-CoV-2 infection compared with no infection, stratified by vaccination status. Random-effects meta-analyses were conducted to estimate pooled hazard ratios (HRs) comparing vaccinated and unvaccinated individuals across prespecified outcomes. Results Twenty-three studies were included in the systematic review; most reported an association between vaccination and a reduced risk of post-infection vascular events. Ten studies were included across meta-analyses comparing vaccinated and unvaccinated individuals. Pre-infection vaccination was associated with significantly reduced risks of composite cardiovascular/cerebrovascular events (HR 0.60, 95% confidence intervals [CI] 0.51-0.69), stroke (HR 0.75, 95% CI 0.64-0.88), acute coronary syndrome (HR 0.70, 95% CI 0.52-0.95), arrhythmias (HR 0.82, 95% CI 0.69-0.98), and venous thromboembolism (HR 0.51, 95% CI 0.36-0.73). No statistically significant reduction was observed for heart failure (HR 0.72 [95% CI 0.47-1.10]). Conclusions Pre-infection COVID-19 vaccination is associated with lower risks of cardiovascular, cerebrovascular and venous thromboembolism events following SARS-CoV-2 infection in the pre- and post-Omicron eras, supporting its role within broader prevention strategies