A Boston hospital is defending itself after a man’s family claimed he was denied a new heart for refusing to be vaccinated against COVID-19, saying most transplant programs around the country set similar requirements to improve patients’ chances of survival.

The family of D.J. Ferguson said in a crowdfunding appeal this week that officials at Brigham and Women’s Hospital told the 31-year-old father of two that he was ineligible for the procedure because he hasn’t been vaccinated against the coronavirus.

“We are literally in a corner right now. This is extremely time sensitive,” the family said in its fundraising appeal, which has raised tens of thousands of dollars. “This is not just a political issue. People need to have a choice!”

D.J.’s mother, Tracey Ferguson, insists that her son isn’t against vaccinations, noting he’s had other immunizations in the past. But the trained nurse said Wednesday that he’s been diagnosed with atrial fibrillation — an irregular and often rapid heart rhythm — and that he has concerns about the side effects of the COVID-19 vaccine.