Why CDC measures vaccine effectiveness

Details

• Corporate Authors:
  National Center for Immunization and Respiratory Diseases (U.S.). Division of Viral Diseases.
• Description:
  Updated Mar. 9, 2021
  
  After the U.S. Food and Drug Administration (FDA) approves a vaccine or authorizes a vaccine for emergency use, experts continue to assess vaccine effectiveness—or how a vaccine works in real-world conditions. The goal is to understand how a vaccine protects people outside of strict clinical trial settings.
  
  CDC and other partners will continue to assess how COVID-19 vaccines work in real-world conditions. Assessing how vaccines work in the real-world is important to:
  
  • Learn if vaccines offer the same protection seen in clinical trials.
  
  • Adjust vaccine recommendations, as needed.
  
  • Learn why and how often breakthrough cases (people getting sick after vaccination) occur.
  
  • Learn how vaccines protect against COVID-19 variants.
  
  • Inform vaccine policy and widespread vaccine distribution.
  
  • Inform future development of improved vaccine technologies.
  
  
• Subjects:
  Coronavirus Infections/prevention & Control COVID-19 Vaccines Pandemics Viral Vaccines
• Document Type:
  Webpage
• Collection(s):
  Stephen B. Thacker CDC Library
• Main Document Checksum:
  urn:sha256:3553ce9c825d62af89b89fcb5c77ad7bac1335f46723f568538f27c7d16b729e
• Download URL:
  https://stacks.cdc.gov/view/cdc/103872/cdc_103872_DS1.pdf
• File Type:
  [PDF - 111.92 KB ]