Being previously infected with a coronaviruses that cause the "common cold" may decrease the severity of severe acute respiratory syndrome coronavirus (SARS-CoV-2) infections, according to results of a new study. Led by researchers at Boston Medical Center and Boston University School of Medicine, the study also demonstrates that the immunity built up from previous non-SARS-CoV-2 coronavirus infections does not prevent individuals from getting COVID-19. Published in the Journal of Clinical Investigation, the findings provide important insight into the immune response against SARS-CoV-2, which could have significant implications on COVID-19 vaccine development.