BOSTON (CBS NEWS) — A Boston hospital says it won’t consider performing a heart transplant on a patient who refuses to get vaccinated against COVID-19, CBS Boston reports.

DJ Ferguson, 31, is fighting for his life at Brigham and Women’s Hospital and in desperate need of a heart transplant.

His father, David Ferguson, is speaking out passionately on behalf of his son who, he told CBS Boston, “has gone to the edge of death to stick to his guns and he’s been pushed to the limit.”

DJ’s family says he was at the front of the line to receive a transplant but hospital policy stipulates that he’s no longer eligible because he hasn’t received the vaccination.

And David Ferguson says his son simply won’t.

“It’s kind of against his basic principles — he doesn’t believe in it,” David Ferguson says. “It’s a policy they are enforcing and so, because he won’t get the shot, they took him off the list (for) a heart transplant.”

Brigham and Women’s released a statement saying, “Like many other transplant programs in the United States – the COVID-19 vaccine is one of several vaccines and lifestyle behaviors required for transplant candidates in the Mass General Brigham system in order to create both the best chance for a successful operation and also the patient’s survival after transplantation.”

Dr. Arthur Caplan, the head of Medical Ethics at NYU Grossman School of Medicine, explains that being vaccinated is necessary for this type of procedure.

“Post any transplant, kidney, heart whatever, your immune system is shut off,” Caplan said. “The flu could kill you, a cold could kill you, COVID could kill you. The organs are scarce, we are not going to distribute them to someone who has a poor chance of living when others who are vaccinated have a better chance post-surgery of surviving.”

DJ is a father of two children with a third child on the way. His family says they’re not sure what they plan to do. They’re thinking about transferring him, but he may be too weak to be moved.

“We are aggressively pursuing all options, but we are running out of time,” David Ferguson said.

And while the family says DJ has received great care from doctors and nurses at Brigham and Women’s, they just don’t agree with the heart transplant COVID vaccination policy.

“I think my boy is fighting pretty damn courageously and he has integrity and principles he really believes in and that makes me respect him all the more,” David Ferguson said.

Which is why the family is sticking by his side and hoping for the best. “It’s his body. It’s his choice,” Ferguson added.