Ultraviolet A Radiation and COVID-19 Deaths in the USA with replication studies in England and Italy
AbstractSeasonal variation in environmental meteorological conditions affect the incidence of infectious diseases. Ultraviolet A (UVA) radiation induces release of cutaneous photolabile nitric oxide (NO) impacting the cardiovascular system and metabolic syndrome, COVID-19 risk factors. NO also inhibits the replication of SARS-CoV. We therefore model the relationship between UVA radiation, derived from remote sensed data, and COVID-19 deaths for counties across the USA during their ‘UV vitamin D winter’ (Jan-April) adjusting for confounding including by temperature and humidity. The Mortality Risk Ratio (MRR) falls by 29% (40% -15% (95% CI)) per 100 (KJ/m2) increase in mean daily UVA. We replicate this in independent studies in Italy and England and estimate a pooled decline in MRR of 32% (48%-12%) per 100 KJ/m2 across the three studies.