About COVID-19 Vaccines

Three COVID-19 vaccines have received emergency use authorization (EUA) from the U.S. Food and Drug Administration – the Pfizer-BioNTech vaccine and the Moderna vaccine, which both require two doses, and Johnson & Johnson (Janssen), which requires only one shot.

The FDA has since given full approval to the Pfizer-BioNTech vaccine for use in people age 16 and older. Its use in those age 5-15 remains under an emergency use authorization. 

In December 2021, the CDC recommended that the Pfizer-BioNTech and Moderna vaccines be preferred over the Johnson & Johnson vaccine because of the risk of a rare but serious side effect. UK HealthCare no longer offers the Johnson & Johnson vaccine, but those who received this vaccine may receive a booster of their choice of Pfizer or Moderna. 

• On Dec. 11, 2020, the FDA issued EUA for the Pfizer-BioNTech vaccine. See:
  Pfizer-BioNTech COVID-19 Vaccine EUA Fact Sheet for Recipients and Caregivers
• On Dec. 18, 2020, the FDA issued EUA for the Moderna vaccine. See: 
  Moderna COVID-19 Vaccine EUA Fact Sheet for Recipients and Caregivers
• On Feb. 27, 2021, the FDA issued EUA for the Johnson & Johnson vaccine. See: 
  Johnson & Johnson COVID-19 Vaccine EUA Fact Sheet for Recipients and Caregivers

Studies from Pfizer and Moderna have shown their vaccines to be 95% and 94.5% effective against COVID-19, respectively. The Johnson & Johnson (Janssen) vaccine has been shown to be 63% effective.

• Learn more about how COVID-19 vaccines work from the Centers for Disease Control and Prevention.
• See Answers to common COVID-19 questions