Study: third dose increases COVID-19 immunity in transplant patients

Posted at 5:57 PM, Jun 17, 2021
and last updated 2021-06-17 18:19:13-04

BALTIMORE — Even after getting fully vaccinated, there’s a worry, especially for immunocompromised people, that it won’t give them a high level of protection. Still, Marla Mulcahy, from Baltimore County, knew she wanted to try.

"I certainly wanted to try to be protected," said Mulcahy.

As a double lung transplant recipient on immunosuppression medications, she’s vulnerable, not only to viruses, but to protection.

After getting both doses of Moderna, she got antibody tested, only to find out she had absolutely none.

"But I wasn’t surprised," said Mulcahy.

That’s because the medications transplant patients take prevent rejection of their transplanted organs but can also interfere with the patients ability to make protective antibodies.

"We are only seeing about 20 perent of transplant patients with a high level of antibodies after vaccination," said Dr. Dorry Segev, a transplant surgeon and researcher at Johns Hopkins University.

But thanks to his study, now Mulcahy and many others have hope that there’s an answer.

"The work we are doing to try and improve this immune response ... is going to impact hundreds of thousands of people in the country," said Segev.

In a new study, Segev and other researchers found that getting third doses of a COVID-19 vaccine increased the immune response in many of the transplant patients involved.

“Our findings revealed that a third of the participants who had negative antibody levels and all who had low positive levels before the booster increased their immune response after a third vaccine dose," said Segev. "This is giving us hope that we will be able to figure out for most people, even people taking immunosuppression, some way of getting their immune system to respond to the vaccine and to give them protect."

This was an observational study. The 30 organ transplant patients involved got third doses in consultation with their doctors, not Johns Hopkins, but then researchers tracked the impact.

Segev said the results were encouraging but there needs to be more studies of the risks.

"There’s a risk that we might get a rejection in someone’s immune system we activated hoping to get a vaccine response but now we have activated the immune system against the organ as well," said

There was one case of mild organ rejection during the study.

While the observational study continues, Segev hopes to launch an interventional trial this summer, so they can continue to study the impacts while keeping a close eye on the transplants.

Mulcahy is hoping to participate.

"I am thrilled," said Mulcahy. "I would take as many shots as they told me to."

To learn more about the study and potential trial, click here.