Exercising caution in correlating COVID-19 incidence and mortality rates with BCG vaccination policies due to variable rates of SARS CoV-2 testing

Janine Hensel; Daniel J McGrail; Kathleen M McAndrews; Dara Dowlatshahi; Valerie S LeBleu; Raghu Kalluri

We collected information for BCG vaccination policies, BCG strains, and TB incidence across all countries from the BCG World Atlas (http://www.bcgatlas.org/). For analysis of countries with past BCG vaccination policy, countries with a year BCG was introduced and stopped were included. Data for Israel showed a change in policy in 1982, but did not specify cessation, therefore it was excluded from analysis. The BCG World Atlas was last updated in 2017. Data of total COVID-19 cases, new COVID-19 cases, first reported COVID-19 cases, mortality, and testing rates for each country was obtained April 7 th , 2020 using https://www.worldometers.info/coronavirus/. Total population, population density (population/km 2 ), net migrants, and median age were obtained from: https://www.worldometers.info/world-population/population-by-country/ (2020). Percent female population (2017) was obtained from: https://ourworldindata.org/grapher/share-population-female. Rate of smokers (2016) was obtained from: https://ourworldindata.org/smoking. Heart disease-related mortality (2002) was obtained from: https://www.who.int/cardiovascular_diseases/en/cvd_atlas_29_world_data_table.pdf World maps were generated using: https://mapchart.net/world.html. variables were z-normalized for equivalent scaling, and p values corrected using Benjamini and Hochberg procedure for univariate comparisons. BCG vaccination (BCG Vac.) was treated as continuous variable with 0 for never universal BCG policy, 1 for universal BCG policy in the past, and 2 for current universal BCG policy. For some comparisons, countries were limited to those with testing rates of 2,500 tests per million and greater, as specified in the results.