COVID-19 Vaccine and Mortality: Systematic Review with SAIMSARA

A large-scale systematic review was conducted with ☸️SAIMSARA on Europe PMC titles/abstracts. Original studies assessing the association between COVID-19 vaccination and mortality were algorithmically identified and synthesized. From 12,371 records, 4,073 studies (ΣN Participants=19,780,831) were included. An LLM-only Outcome-Sentiment Meta-Analysis classified findings as beneficial for 55% of participants (ΣN Participants=10,896,598), neutral for 44% (ΣN Participants=8,663,236), and harmful for 1% (ΣN Participants=220,997). Across studies reporting vaccine effectiveness (VE) against COVID-19–related or all-cause mortality, an unweighted median VE of 84.24% (range 53–100%) was observed, with stronger protection after booster doses and across vulnerable groups. No excess non-COVID mortality after vaccination was detected. Heterogeneity of designs, variable outcome definitions, retrospective data, and potential “healthy vaccinee” bias limit causal inference. Overall, substantial mortality reduction associated with COVID-19 vaccination was found, and standardized, prospective, variant-aware evaluations were indicated to refine estimates and guide booster policy.