3rd Doses and Booster Doses

Both 3rd dose and boosters COVID vaccines have different purposes and are intended for different groups of people.  A third dose of the Pfizer and Moderna COVID-19 vaccine can help protect people with weakened immune systems who did not have a strong enough response to the first two doses of the vaccines, and is available to get after 28 days of the last dose of vaccine.  A COVID booster shot is an additional dose of a vaccine given after the protection provided by the original shot(s) has begun to decrease over time, and is available to get 6 months after the last dose of vaccine.

3rd Doses

Third doses of Pfizer or Moderna vaccines are available at least four weeks (28 days) after completing the original two-dose vaccine series for individuals in the following categories:

• Recipients of organ or stem cell transplants
• People with advance or untreated HIV infection
• Active recipients of treatment for cancer
• People who are taking some medications that weaken the immune system

Booster Doses

Booster doses are available for the Pfizer vaccine at least 6 months after the second dose of Pfizer for the following individuals:

• People 65 years and older and residents in long-term care settings
• People aged 50–64 years with underlying medical conditions, which include but are not limited to: cancer, chronic heart, lung and kidney diseases, dementia, diabetes, down syndrome, HIV, overweight and obesity, pregnancy, organ transplants, and stroke
• People aged 18–49 years with underlying medical conditions (the same categories as mentioned above), based on their individual benefits and risk
• People aged 18–64 years who are at increased risk for COVID-19 exposure and transmission because of occupational or institutional setting, including first responders (health care workers, firefighters, police, congregate care staff); education staff (teachers, support staff, daycare workers); manufacturing workers; Corrections workers; U.S. Postal Service workers; public transit workers; grocery store workers; and those who reside in correctional facilities or homeless shelters