Dartmouth-Hitchcock answers questions about third COVID vaccine dose for immunocompromised people

LEBANON — On Thursday, Aug. 12, the U.S. Food and Drug Administration authorized the use of a third dose of the Pfizer and Moderna COVID-19 vaccines for immunocompromised people, with the third dose to be administered at least 28 days following the first two doses.

“This is different than a booster dose that is being discussed for the general population. Instead, this third dose is recommended as part of the primary series for people with medical conditions or receiving treatments associated with being moderate-to-severely immunocompromised,” said Michael S. Calderwood, MD, chief quality officer at Dartmouth-Hitchcock Medical Center. “We have data showing that people who are immunocompromised are more likely to develop breakthrough infections resulting in hospitalization, that the vaccine effectiveness and antibody response is lower in people who are immunocompromised after two doses of an mRNA vaccine, and that a third dose of an mRNA vaccine can boost the prevalence of protective antibodies in people who are immunocompromised. As for side effects, these have been reported as similar to prior doses and mostly mild or moderate.”