For each vaccines, the transition from EUA standing to full licensure was based mostly on extra information and longer follow-up displaying that the vaccines met sure security, effectiveness, and manufacturing quality standards. But the current vaccines are based mostly on an earlier version of the SARS-CoV-2 virus. The Omicron variant, for instance, has about 50 mutations, including more than 30 mutations on the spike protein. As the spike protein turns into less recognizable to the immune system, the vaccine turns into less effective at protecting towards infections. Are you trying to scale back your risk of any infection, symptomatic an infection, or severe illness and hospitalization? The answer may depend on your age, medical historical past, and other elements, and will affect how you assume about a second booster.