COVID-19 | Oct. 14, 2021

Post Vaccine and Boosters FAQs

Q: Who is eligible for a third (booster) dose?
A: People who received their second dose of Pfizer COVID-19 vaccine at least six months ago AND are in at least one of the following categories:

  • Persons 65 years and older
  • Persons 18-64 years old with underlying medical conditions
  • Persons 18-64 years who are at increased risk for COVID-19 exposure and transmission because of their occupation or institution


Q: What are some examples of occupations and institutions that might increase risk for COVID-19 exposure and transmission?
A: Occupations may include, but are not limited to, healthcare workers, first responders, education staff, food and agriculture workers, manufacturing workers, corrections workers, postal service workers, public transit workers, and grocery workers. Institutions might include congregate living or working facilities such as educational institutions, training centers, or ships. USCG personnel are considered first responders. Therefore, all USCG members who desire a third dose of Pfizer and received their second dose more than six months ago, may and are encouraged to discuss scheduling a third dose with their clinic/primary care manager.


Q: Does an individual have to prove their occupational/institutional risk or underlying condition?
A: No.


Q: Should individuals who received vaccines other than Pfizer receive booster doses?
A: Individuals who received the Moderna or J&J/Janssen vaccines or a mixed series of vaccines should not receive a booster at this time. These individuals should continue to monitor CDC and FDA websites; booster doses for other vaccines may be recommended at a future date.  


Q: If I think I am eligible for a booster, where can I get one?
A: Pfizer booster shots are available at USCG pharmacies, as well as other locations, including civilian healthcare providers and local pharmacies.


Q: How do I know if it’s been six months since my last dose?
Review your CDC shot card if you have one, check with your PCP or the site where you received your vaccine, or visit your state immunization registry.


Q: When can I get a COVID-19 vaccine booster if I am NOT in one of the recommended groups?
A: Additional people may be recommended to receive a booster shot as more data becomes available. The COVID-19 vaccines approved and authorized in the United States continue to be effective at reducing risk of severe disease, hospitalization, and death. Experts are looking at all available data to understand how well the vaccines are working for different populations. This includes looking at how new variants, like Delta, affect vaccine effectiveness.


Q: What should people who received Moderna or Johnson & Johnson’s Janssen (J&J/Janssen) vaccine do?
A: Currently, the Pfizer booster authorization only applies to people who received both doses of the Pfizer vaccine. People in the recommended groups who received the Moderna or J&J/Janssen vaccine may need a booster shot at some point in the future. More data on the effectiveness and safety of Moderna and J&J/Janssen booster shots are expected soon. CDC will keep the public informed with a timely plan for Moderna and J&J/Janssen booster shots.


Q: How long will protection last following vaccination?
A: We do not know how long protection will last following vaccination but it will be critically important to measure long-term protection in the phase 3 trials and in other groups prioritized for early vaccination. We are still learning about the duration of protection following infection with COVID-19 and it is too early to tell how long protection will last.


Q: Can I still get sick with the COVID-19 disease once I have been vaccinated?
A: Yes, even though the vaccine is highly effective (has a high efficacy), it’s still possible for a vaccinated person to become ill. The protection provided by the vaccine is not immediate after receiving the second dose. Current information indicates it takes time for a person’s immune system to fully respond to the vaccine and produce antibodies. According to the Centers for Disease Control and Prevention (CDC), evidence from clinical trials indicates that the Pfizer vaccine reaches full potential, 95% efficacy, at least 7 days after the second dose. At the 95% effective rate, approximately 5% of those who receive both doses of the vaccine may still get the COVID-19 disease. Clinical trial data for the Moderna vaccine indicate that it reaches full potential, approximately 94% efficacy, at least 14 days after the second dose.

You can read more from the CDC about the different COVID-19 vaccines, including Pfizer and Moderna, at