What you should know about the possibility of COVID-19 illness after vaccination

Details

• Corporate Authors:
  National Center for Immunization and Respiratory Diseases (U.S.). Division of Viral Diseases.
• Description:
  Updated Aug. 16, 2021
  
  COVID-19 vaccines are effective. However, a small percentage of people who are fully vaccinated will still get COVID-19 if they are exposed to the virus that causes it. These are called “vaccine breakthrough cases.” This means that while people who have been vaccinated are much less likely to get sick, it will still happen in some cases. It’s also possible that some fully vaccinated people might have infections, but not have symptoms (asymptomatic infections). Experts continue to study how common these cases are.
  
  Large-scale clinical studies found that COVID-19 vaccination prevented most people from getting COVID-19. Research also provides growing evidence that mRNA COVID-19 vaccines (Pfizer-BioNTech, Moderna) offer similar protection in real-world conditions. While these vaccines are effective, no vaccine prevents illness 100% of the time. For any vaccine, there are breakthrough cases.
  
  
• Content Notes:
  A small percentage of people fully vaccinated against COVID-19 will still develop COVID-19 illness -- Other reasons why fully-vaccinated people might get COVID-19 -- If you get COVID-19 after vaccination, your symptoms might be less severe -- CDC is monitoring COVID-19 vaccine breakthrough cases for patterns.
• Subjects:
  Coronavirus Infections COVID-19 COVID-19 Vaccines Population Surveillance Vaccination
• Document Type:
  Webpage
• Collection(s):
  Stephen B. Thacker CDC Library
• Main Document Checksum:
  urn:sha256:47650b7501c1a113e4aee919641be6fcff69e72eabdae2e2783edd0c19dd9825
• Download URL:
  https://stacks.cdc.gov/view/cdc/108922/cdc_108922_DS1.pdf
• File Type:
  [PDF - 174.64 KB ]