COVID-19 vaccines are effective at keeping you from getting COVID-19 but they have other benefits, too. In the rare case that you do still get COVID-19, the vaccine may help keep you from getting seriously ill. Getting vaccinated may also protect people around you, particularly people at increased risk for severe illness from COVID-19. COVID-19 vaccination is a safer way to help build immunity. COVID-19 can have serious, life-threatening complications, and there is no way to know how COVID-19 will affect you.
COVID-19 vaccines teach our immune systems how to recognize and fight the virus that causes COVID-19. It typically takes a few weeks after vaccination for the body to build protection (immunity) against the virus. That means it is possible a person could still get COVID-19 just after vaccination, because the vaccine has not had enough time to build immunity.
You may have some side effects after vaccination.
COVID-19 vaccines authorized by the FDA have been shown to be safe and effective in clinical trials. All COVID-19 vaccines were authorized only after it was found that they make it substantially less likely you'll get COVID-19.
The authorized vaccines are up to 95% effective against a person becoming ill with COVID-19.
The U.S. vaccine safety system ensures that all vaccines are as safe as possible. Learn how the federal government is working to ensure the safety of COVID-19 vaccines.
Millions of people in the United States have received COVID-19 vaccines. These vaccines have undergone the most intensive safety monitoring in U.S. history, using both established and new safety monitoring systems. These vaccines cannot give you COVID-19. Learn more facts about COVID-19 vaccines.
Results from monitoring efforts are reassuring. Many people have reported only mild side effects after COVID-19 vaccination. Some people have no side effects.