Mandated Bacillus Calmette-Guérin (BCG) vaccination predicts flattened curves for the spread of COVID-19

Martha K Berg; Qinggang Yu; Cristina E Salvador; Irene Melani; Shinobu Kitayama

To overcome this challenge, we examined day-by-day reports of both confirmed cases and deaths and analyzed growth curves in countries with mandated BCG policies versus those without. The growth curves illuminate the process of the viral spread in each country, which in turn shapes the total number of cases or deaths. The start of the growth curves was set to be equal across countries. Following prior work, we focused on a time period either after the first 100 confirmed cases (as in (12) ) or after one confirmed COVID-caused death. Of note, we limited our analysis to the first 30 days of the onset of country-wise outbreaks. This will enable us to capture the initial, exponential spread of the virus, while minimizing any effects of countrydependent coping actions (e.g., stay-home mandates by the state).