GS Medical Director, Dr. Brian Deloach, Answers Students’ COVID-19 vaccine questions

Booster Shots, Vaccine Approval and Immunocompromised Individuals


Samantha Farrington, Staff Writer

How would different vaccines interact with different bodies, specifically those that are immunocompromised?

— Fifth Year Senior, English

A: With regard to vaccines in immunocompromised persons, there are two primary things to consider.  First, persons with certain immunocompromising conditions have been observed to have less of an immune response to vaccines than a person with a fully competent immune system.  Because the purpose of a vaccine is to stimulate the immune system to respond when it detects the virus, if a person has a lower response to the vaccine then they may have a lower level of protection from the vaccine. This is why an additional dose of the Moderna and Pfizer vaccines has been recommended for persons with certain immunocompromising conditions.  The second thing to consider with regard to immunocompromised individuals is that in general they should not receive live vaccines, because severe complications have followed vaccination with certain live, attenuated viral and live, attenuated bacterial vaccines among persons with altered immunocompetence. It is important to note that the COVID-19 vaccines are not “live” vaccines. Persons who are immunocompromised should discuss their vaccine options with their physician.

Personally, I want to know about dates like when did the vaccine get approved?

— Junior, Biology

A: FDA granted an Emergency Use Authorization (EUA) for the Pfizer mRNA vaccine on December 11, 2020, for individuals 16 years of age and older, and the authorization was expanded to include those 12 through 15 years of age on May 10, 2021.  Then, on August 23, 2021 FDA granted full approval to the Pfizer COVID-19 two-dose vaccine for persons age 16 and up, and the EUA for ages 12-15 remains in effect.  FDA granted an EUA for the Moderna mRNA vaccine on December 18, 2020 for individuals 18 years of age and older, and that EUA is still in effect.  Then, on February 27, 2021 FDA granted an EUA for the Janssen/Johnson & Johnson COVID19 vaccine for individuals age 18 years and older, and that EUA is still in effect.  

How effective is it [the vaccine] and which one do you recommend?

— Freshman, Engineering

A: The short answer is that the COVID-19 vaccines currently in use in the United States are safe and highly effective at preventing severe  illness, hospitalizations, and death due to COVID-19.  For more in-depth information about efficacy of the vaccines, the CDC page at is a good resource.  Also, Yale Medicine provides an excellent review of each vaccine, including published efficacy data, at

I heard that there is a third booster shot coming out, so I just want to know how important that is and when we’ll be able to get it.

— Junior, History

A: Currently Pfizer is the only COVID19 vaccine approved for a “booster” dose.  On September 22, 2021 the U.S. Food and Drug Administration amended the emergency use authorization (EUA) for the Pfizer COVID-19 Vaccine to allow for use of a single booster dose, to be administered at least six months after completion of the primary series in:

 -individuals 65 years of age and older;

-individuals 18 through 64 years of age at high risk of severe COVID-19; and 

-individuals 18 through 64 years of age whose frequent institutional or occupational exposure to  SARS-CoV-2 puts them at high risk of serious complications of COVID-19 including severe COVID-19.

 As of right now, this authorization applies only to the Pfizer COVID-19 Vaccine. We expect more guidance regarding booster doses with the other authorized vaccines at a later date. 

 Also, an “additional” (or “3rd”) dose of Pfizer or Moderna is approved for persons who have a qualifying immunocompromising condition.  This dose is not considered a “booster.” For these individuals, the recommendation is that they get the additional dose when at least 28 days have passed since their second dose.  This additional dose should be with the same vaccine as their first and second doses.

Here is the CDC link for information about the “additional” dose that is currently available to persons with certain immunocompromising conditions. If you are an individual who qualifies for a Pfizer booster dose or a Moderna or Pfizer “additional” dose based on the requirements above, you can schedule that dose on campus through your mygeorgiasouthern portal.

Will travel vaccines become mandatory, and how will they be implemented?

— Senior, Health Administration

A: Governments around the world already have various vaccine requirements (not only for COVID-19 but also for other vaccine-preventable illnesses) for travelers entering their country.  To determine what vaccines are required by a specific country, go to and on that page under “Destinations” select the country you are interested in and then click “GO.”  Doing that will take you to a page that lists the required vaccines, as well as those vaccines that are recommended but not required, for that country.  Those pages also list whether the country requires COVID-19 vaccination as a condition of entry.