Time-adjusted Analysis Shows Weak Associations Between BCG Vaccination Policy and COVID-19 Disease Progression.

In this study, we ascertain the associations between BCG vaccination policies and progression of COVID-19 through analysis of various time-adjusted indicators either directly extracted from the incidence and death reports, or estimated as parameters of disease progression models. We observe weak correlation between BCG vaccination status and indicators related to disease reproduction characteristics. We did not find any associations with case fatality rates (CFR), but the differences in CFR estimates are at present likely dominated by differences in testing and case reporting between countries. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work has been supported by the Slovak Research and Development Agency under the contracts no. APVV-18-0239 (T.V., B.B.), APVV-18-0308 (R.K.) and by the Scientific Grant Agency of the Slovak Republic under the grants no. 1/0458/18 (T.V.), 1/0463/20 (B.B.), 1/0755/19 (R.K.), and 1/0521/20 (K.B.) ### Author Declarations All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript. Yes All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I 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). Yes I 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. Yes All datasets used for analysis in this study are publicly available in the repositories cited in the article.