Key Things to Know About COVID-19 Vaccines
Because COVID-19 is a new disease with new vaccines, information is rapidly emerging about how vaccines can help us stop the pandemic. CDC will update this page with more information about what we know—and what we don’t know—as it becomes available. Learn more facts about COVID-19 vaccines.
Currently, two vaccines are authorized and recommended to prevent COVID-19:
Learn more about the different COVID-19 vaccines.
COVID-19 vaccines and herd immunity
Herd immunity means that enough people in a community are protected from getting a disease because they’ve already had the disease or because they’ve been vaccinated. Herd immunity makes it hard for the disease to spread from person to person, and it even protects those who cannot be vaccinated, like newborns or people who are allergic to the vaccine. The percentage of people who need to have protection to achieve herd immunity varies by disease.
What we do not know
Experts do not yet know what percentage of people would need to get vaccinated to achieve herd immunity to COVID-19. CDC and other experts are studying herd immunity and will provide more information as it is available.