Key Things to Know About COVID-19 Vaccines

effectiveness

COVID-19 vaccines are effective at protecting you against COVID-19, especially serious illness and death. COVID-19 vaccines can reduce the risk of people spreading the virus that causes COVID-19. If you are fully vaccinated, you can resume your pre-pandemic activities. Find out more about what to do when you are fully vaccinated.

Studies show that COVID-19 vaccines are effective, especially at preventing you from getting seriously ill, even if you do get COVID-19. Learn more about the benefits of vaccination.

COVID-19 vaccines teach our immune systems to recognize and fight the virus that causes COVID-19. It usually takes time 2 weeks after vaccination for the body to build up protection (Immunity) to the virus that causes COVID-19. This means that it is possible that a person could still get COVID-19 before or shortly after the vaccination and then get sick because the vaccine did not have enough time to build up protection.

Individuals are considered fully vaccinated 2 weeks after their second dose of Pfizer BioNTech or Moderna COVID-19 vaccine or 2 weeks after the Johnson & Johnson Janssen COVID-19 vaccine single dose. To get the greatest possible protection, people should received all recommended doses a COVID-19 vaccine. Find out more about who is recommended an additional dose or a booster dose.

People can sometimes get COVID-19 after being fully vaccinated. However, even with the delta variant, this only happens to a small proportion of people. When these infections occur in people who have been vaccinated, they are usually mild.

Learn more about the effectiveness of COVID-19 vaccines.