Scientists at the National Institutes of Health have found that a process in cells may limit infectivity of SARS-CoV-2, and that mutations in the alpha and delta variants overcome this effect, potentially boosting the virus’s ability to spread. The findings were published online in the Proceedings of the National Academy of Sciences. The study was led by Kelly Ten Hagen, Ph.D., a senior investigator at NIH’s National Institute of Dental and Craniofacial Research (NIDCR).