COVID-19 vaccine booster shots safe and beneficial for heart transplant patients

On Aug. 12, the FDA cleared the use of COVID-19 booster shots for certain patient populations with compromised immune systems. According to a new editorial published on the American College of Cardiology's website, these boosters appear to be safe—and quite beneficial—for heart transplant patients. 

The editorial was written by Biykem Bozkurt, MD, PhD, and Savitri Fedson, MD, MA, both from Baylor College of Medicine in Houston. Bozkurt and Fedson began their commentary by noting that the mRNA vaccinations currently available to the public offer "suboptimal protection" for immunocompromised patients. 

“Immune response to vaccination is significantly lower in these patients than the normal population," they explained. "Data show that mRNA vaccine efficacy against new variants such as Delta B.1.617.2 is around 79 to 88% in the normal population after the second dose, but even lower in the immunocompromised patients.

The two authors also wrote that almost half of the patients who undergo cardiac transplants do not generate IgG antibodies after they receive two doses of the SARS-CoV-2 mRNA vaccine.

Bozkurt and Fedson also examined early evidence that emphasizes the benefits of COVID-19 booster shots.

“Initial reports of case series are now followed by strong evidence from a randomized clinical trial demonstrating that a third dose of mRNA vaccine given to 120 solid organ transplant recipients (18 of which were heart transplant recipients) three months after the first two doses resulted in a substantially higher immunogenicity compared with placebo and was quite safe,” they wrote. 

In addition, among patients who received the booster dose of the mRNA vaccine, there were no incidents of hospitalizations or cases of organ rejection.

“These data support that a third dose of the mRNA vaccination is highly beneficial with low risk in solid-organ transplant patients and should be considered in cardiac transplant recipients,” the authors wrote. “It should be kept in mind that in the recently published randomized clinical trial, even after the third dose, only 55% of the transplant recipients had an antibody level above the protective threshold of 100 U per milliliter. Thus, barrier measures should continue to be maintained, and vaccination of the relatives and contacts of these patients should be strongly enforced in addition to the third booster consideration in cardiac transplant patients."

Read the full editorial here.

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