Case fatality rates of COVID‐19 during epidemic periods of variants of concern: A meta-analysis by continents

Abstract

ObjectivesTo calculate the case fatality rates (CFR) of COVID‐19 during epidemic periods of different variants of concern (VOC) by continents. MethodsWe systematically searched five authoritative databases (Web of Science, PubMed, Embase, Cochrane Library, and MedRxiv) for epidemiological studies on the CFR of COVID-19 published between January 1, 2020, and March 31, 2023. After identifying the epidemic trends of variants, we used a random-effects model to calculate the pooled CFRs during periods of different VOCs. This meta-analysis was conducted following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and registered with PROSPERO (CRD42023431572). ResultsThere were variations in the CFRs among different variants of COVID-19 (Alpha: 2.62%, Beta: 4.19%, Gamma: 3.60%, Delta: 2.01%, Omicron: 0.70%), and disparities in CFRs also existed among continents. On the whole, the CFRs of COVID-19 in Europe and Oceania were slightly lower than in other continents. There was a statistically significant association between the variant, HDI value, age distribution, coverage of full vaccination of cases, and the CFR. ConclusionsThe CFRs of COVID-19 varied across the epidemic periods of different VOCs, and disparities existed among continents. The CFR value reflected combined effects of various factors within a certain context. Caution should be exercised when comparing CFRs due to disparities in testing capabilities and age distribution among countries, etc.