Key Things to Know About COVID-19 Vaccines - from the CDC: Studies show that COVID-19 vaccines are effective at keeping you from getting COVID-19. Experts also think that getting a COVID-19 vaccine may help keep you from getting seriously ill even if you do get COVID-19. But while COVID-19 vaccines can keep you from getting sick, scientists are still learning how well vaccines prevent you from spreading the virus that causes COVID-19 to others. So even after vaccination, we need to continue using all the tools available to help stop this pandemic as we learn more about how COVID-19 vaccines work in real-world conditions. Although the vaccine supply is currently limited, the federal government is working toward making vaccines widely available.