Clinical Research Supports Efficacy of COVID Booster for Immunocompromised Patients, Federal Authorization Expected to Follow

July 27, 2021

During an Advisory Committee on Immunization Practices (ACIP) meeting last week, CDC staff confirmed that a third dose booster may be on the horizon for those who are immunocompromised. This comes after promising data of a third dose eliciting a robust immune response in those who had previously received a full dose of the COVID-19 vaccine but were unable to produce detectable antibodies.

The meeting referenced a study of 99 solid-organ transplant patients who received a third dose. In the study, the prevalence of anti–SARS-CoV-2 antibodies was 4% after the first dose, 40% after the second dose, and 68% 4 weeks after the third dose. 

“Among the 59 patients who had been seronegative (no presence of virus in blood serum) before the third dose, 26 (44%) were seropositive at 4 weeks after the third dose.” Patients who did not elicit an antibody response were typically older, with a higher degree of immunosuppression, and a lower rate of kidney function.

No serious adverse events were reported by the cohort.

As of now, the use of a third dose would require a separate Emergency Use Authorization by the FDA. Once vaccines are FDA approved, doctors will be able to prescribe a booster to patients directly. Until then, patients may be able to access a third dose through investigational studies; some patients have also taken it upon themselves to obtain a third dose.