TY - JOUR T1 - Association between live childhood vaccines and COVID-19 outcomes: a national-level analysis JF - medRxiv DO - 10.1101/2020.10.17.20214510 SP - 2020.10.17.20214510 AU - Ogimi, Chikara AU - Qu, Pingping AU - Boeckh, Michael AU - Bender Ignacio, Rachel A. AU - Zangeneh, Sahar Z. Y1 - 2020/01/01 UR - http://medrxiv.org/content/early/2020/10/20/2020.10.17.20214510.abstract N2 - We investigated whether countries with higher coverage of childhood live vaccines [BCG or measles-containing-vaccine (MCV)] have reduced risk of COVID-19 related mortality, accounting for known systems differences between countries. In this ecological study of 140 countries using publicly available national-level data, higher vaccine coverage, representing estimated proportion of people vaccinated during the last 15 years, was associated with lower COVID-19 deaths. The associations attenuated for both vaccine variables, and MCV coverage became no longer significant once adjusted for a validated summary score accounting for life expectancy and healthcare quality indicators, the Healthcare access and quality index (HAQI). The magnitude of association between BCG coverage and COVID-19 death rate varied according to HAQI, and MCV coverage had little effect on the association between BCG and COVID-19 deaths. While there are associations between live vaccine coverage and COVID-19 outcomes, the vaccine coverage variables themselves were strongly correlated with COVID-19 testing rate, HAQI, and life expectancy. This suggests that the population-level associations may be further confounded by differences in structural health systems and policies. Cluster randomized studies of booster vaccines would be ideal to evaluate the efficacy of trained immunity in preventing COVID-19 infections and mortality in vaccinated individuals and on community transmission.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis work was supported by the National Institutes of Health (K23AI139385 to C.O., K23AI129659 to RBI)Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This is a country base ecological study and does not deal with any individual patients' data; therefore, IRB approval is not required.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesOriginal data are available by request to the corresponding author. ER -