evidence: That’s why being up to date on COVID-19 vaccinations remains a global health priority, says infectious disease specialist Kristin Englund, MD. Here’s what you need to be considered fully vaccinated for COVID-19. [...] COVID-19 vaccination guidance from the CDC varies by a person’s age, vaccination record and health condition. Here’s a rundown: [...] It takes about two weeks after getting a COVID-19 vaccination for your body to build up immunity against the virus, says Dr. Englund. After that, you’re considered "fully vaccinated" against COVID-19.