A new paper in Biology Methods & Protocols investigates risk factors and protections against contracting COVID-19, and also for suffering from severe COVID. Researchers have identified several characteristics—including male sex, lower age, blood group B, and larger household size—that increased the risk of infection and many other characteristics—including mask-wearing and using vitamin D—that decreased it. They also identified the things that increased or decreased the risk of a severe course of COVID-19. Some of these findings are unexpected.
SARS-CoV-2 has infected more than 600 million people worldwide, resulting in 6.57 million confirmed deaths. But information about factors affecting the probability of infection or suffering from a severe course of the disease remains insufficient and often speculative. Preregistered longitudinal studies about the risk factors of infection are surprisingly rare. Many…