Global impact of environmental temperature and BCG vaccination coverage on the transmissibility and fatality rate of COVID-19

• DOI: 10.1371/journal.pone.0240710
• Publication Date: 2020-10-22T17:28:53Z
• Authors: Amit Kumar; Shubham Misra; Vivek Verma; Ramesh K. Vishwak...; Vineet Kumar Kamal; Manabesh Nath; Kiran Prakash; Ashish Datt Upadhyay; Jitendra Kumar Sahu
• Keywords: Quartile; Interquartile range; Case fatality rate; Rate ratio

The 2019-Coronavirus (COVID-19) pandemic has had a global impact. effect of environmental temperature on transmissibility and fatality rate COVID-19 protective efficacy Bacillus Calmette-Guérin (BCG) vaccination towards remains ambiguous. Therefore, we explored the impact neonatal BCG coverage COVID-19. data for reported cases, deaths were collected from 31st December 2020 to 3rd April 67 countries. Temperature split into quartiles all three categories (minimum temperature, maximum mean temperature). types policy infection was determined by applying multivariable two-level negative binomial regression analysis keeping daily new cases mortality as outcome. highest number fell in following: second quartile (6°C 10.5°C), median 26, interquartile range (IQR) 237; minimum first (-26°C 1°C), 23, IQR 173; (10°C 16°C), 27.5, 219. For category, 28% statistically significant lower incidence noted countries falling (2°C 6°C) compared with 1°C) (incidence ratio [IRR] 0.72, 95% confidence interval [CI] 0.57 0.93). However, no difference observed comparison quartile. Countries 58% less without (IRR 0.42; CI 0.18 0.95). Our exploratory study provides evidence that high might not be associated low having