A US hospital has rejected a patient for a heart transplant at least in part because he is not vaccinated against Covid-19.
DJ Ferguson, 31, is in dire need of a new heart, but Brigham and Women's Hospital in Boston took him off their list, said his father, David.
He said the Covid vaccine goes against his son's "basic principles, he doesn't believe in it".
The hospital said it was following policy.
Brigham and Women's Hospital told the BBC in a statement: "Given the shortage of available organs, we do everything we can to ensure that a patient who receives a transplanted organ has the greatest chance of survival."
A spokesman said the hospital requires "the Covid-19 vaccine, and lifestyle behaviours for transplant candidates to create both the best chance for a successful operation and to optimise the patient's survival after transplantation, given that their immune system is drastically suppressed".
The hospital's carefully worded statement may suggest other factors lie beyond the patient's unvaccinated status for his ineligibility, but it refused to discuss specifics, citing patient privacy.
The hospital added that most of the 100,000 people on waitlists for organ transplants will not receive an organ within five years because of the shortage of available organs.
Mr Ferguson has been in hospital since last Thanksgiving weekend, 26 November 2021, and he suffers from a hereditary heart issue that causes his lungs to fill with blood and fluid, according to a GoFundMe.
The organiser of the fundraiser said Mr Ferguson was concerned he could experience cardiac inflammation - a potential side effect from coronavirus vaccination that the US Centers for Disease Control and Prevention (CDC) emphasises is rare and temporary - and that it might prove dangerous given the weakness of his heart.
The CDC encourages transplant recipients and those in their immediate circles to get fully vaccinated and boosted.
Dr Arthur Caplan, head of medical ethics at NYU Grossman School of Medicine, told CBS News that after any organ transplant a patient's immune system is all but shut down and even a common cold can prove fatal.
"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," said Dr Caplan.
A father-of-two with a third child on the way, Mr Ferguson remains at the hospital, said his loved ones.
His family has suggested he is too weak to be transferred to a different hospital and is "running out of time".
"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," said David Ferguson.
"It's his body. It's his choice."
It is not the first time an unvaccinated American has faced healthcare obstacles in recent weeks.
Earlier this month, a Minnesota woman sued her local hospital after doctors tried to take her unvaccinated husband off the ventilator he had been on for two months.
Just over 63% of the US population is double-jabbed and about 40% of Americans have received a third booster dose.