ATLANTA, GA-COVID-19 vaccination reduces the risk of COVID-19 and its potentially severe complications. While COVID-19 vaccines are working well, some people who are fully vaccinated against COVID-19 will still get sick, because no vaccines are 100% effective. These are called vaccine breakthrough cases. mRNA COVID-19 vaccines have been shown to provide protection against severe illness and hospitalization among people of all ages eligible to receive them. This includes people 65 years and older who are at higher risk of severe outcomes from COVID-19.
- Research shows that all COVID-19 vaccines authorized for use in the United States provide protection against COVID-19.
- CDC and other experts are continuing to assess how COVID-19 vaccines work in real-world conditions. These types of studies are called “vaccine effectiveness” studies.
What We Know about How Well COVID-19 Vaccines Are Working
COVID-19 vaccination reduces the risk of COVID-19 and its potentially severe complications. All COVID-19 vaccines currently authorized for use in the United States helped protect people against COVID-19, including severe illness, in clinical trial settings. So far, studies that have looked at how COVID-19 vaccines work in real-world conditions (vaccine effectiveness studies) have shown that these vaccines are working well.
Most vaccine effectiveness data now available are related to mRNA vaccines (Pfizer-BioNTech and Moderna) because these vaccines have been available longer. CDC and other experts continue to study the effectiveness of both mRNA vaccines and the Johnson & Johnson’s Janssen (J&J/Janssen) COVID-19 vaccine in real-world conditions.
Vaccine effectiveness studies provide a growing body of evidence that mRNA COVID-19 vaccines offer similar protection in real-world conditions as they have in clinical trial settings, reducing the risk of COVID-19, including severe illness, among people who are fully vaccinated by 90 percent or more. Most vaccine effectiveness data now available are related to mRNA vaccines. Data related to the J&J/Janssen vaccine will be shared when available.
In addition to providing protection against COVID-19, there is increasing evidence that COVID-19 vaccines also provide protection against COVID-19 infections without symptoms (asymptomatic infections). COVID-19 vaccination can reduce the spread of disease overall, helping protect people around you.
While COVID-19 vaccines are working well, some people who are fully vaccinated against COVID-19 will still get sick, because no vaccines are 100% effective. These are called vaccine breakthrough cases. However, data suggest that vaccination may make symptoms less severe in people who are vaccinated but still get COVID-19. mRNA COVID-19 vaccines have been shown to provide protection against severe illness and hospitalization among people of all ages eligible to receive them. This includes people 65 years and older who are at higher risk of severe outcomes from COVID-19.
It typically takes about 2 weeks for the body to build protection after vaccination. You are fully vaccinated two weeks after your second dose of Pfizer -BioNTech or Moderna vaccine and two weeks after your single dose of Johnson & Johnson’s J&J/Janssen vaccine. It is possible you could still get COVID-19 soon after vaccination because your body has not had enough time to build protection. Keep taking precautions until you are fully vaccinated.
People who have a condition or are taking medications that weaken their immune system may not be fully protected even if they are fully vaccinated. They should continue to take all precautions recommended for unvaccinated people, including wearing a well-fitted mask, until advised otherwise by their healthcare
provider.
NOTICE: HHS announced a plan to begin offering COVID-19 vaccine booster shots this fall. CDC’s independent advisory committee, the Advisory Committee on Immunization Practices, will continue to meet and discuss data on the evolution of the pandemic and the use of COVID-19 vaccines. ACIP will make further recommendations on the use of boosters for the public after a thorough review of the evidence.
Media Release/Centers for Disease Control and Prevention
