DJ Ferguson, 31, has spent almost 50 days in hospital, and is now in end-stage heart failure and needs a transplant to survive.

Brigham and Women's Hospital policy states he is no longer eligible because he hasn't received a coronavirus vaccination - something his family said he refuses to do.

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"The transplant board will not actively list him due to his vaccination status," Mr Ferguson's family said on a GoFundMe charity fundraising page.

His family is concerned the vaccine could cause his heart to swell, and put him at "extremely high risk of sudden death".

"We're being pressured to choose a shot that could kill him. This is not just a political issue," they added.

"People need to have a choice! People need to realize that there ARE others out there that are at high risk while receiving this shot, and it COULD kill them."

The father-of-two, who has another child on the way, suffers from a hereditary heart issue and was first taken to hospital on Thanksgiving weekend in November with suspected pneumonia.

"Brigham told us he has to have the vaccine to accept a heart," his mother Tracey Ferguson said.

"He is not an anti-vaxx person. He has all of his vaccines, but there are some adverse reactions given his condition, and he is a man, he made his decision."

She added: "He said to the doctor, 'Are you really going to let me die over a shot?'

"All of my children, they are all vaccinated, he did his own homework, and made his own decision."

His family has looked at transporting him to another hospital but said he is currently too sick to be moved.

Brigham and Women's Hospital said it couldn't comment on individual patients due to US laws.

"Our Mass General Brigham healthcare system requires several CDC-recommended vaccines, including the COVID-19 vaccine, and lifestyle behaviours for transplant candidates to create both the best chance for a successful operation and to optimize the patient's survival after transplantation, given that their immune system is drastically suppressed," the hospital said in a statement.

Dr Arthur Caplan, the head of medical ethics at NYU Grossman School of Medicine, told CBS News the vaccine was necessary for this kind of procedure.

"Post any transplant, kidney, heart, whatever, your immune system is shut off," he 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."