New research shows that immunocompromised people have a tough time developing antibodies to COVID-19, a reason why one Long Island man says he hasn't been anywhere or seen anyone in 15 months.

William Nelson, 81, is a retired NYU law professor who has been playing it safe since the pandemic hit because he is immunocompromised. Nelson was diagnosed eight years ago with chronic lymphocytic leukemia so he decided he would get the COVID-19 vaccine. He did but then later tests showed he had no antibodies from the vaccine.

According to doctors, some studies now show that the COVID-19 vaccines don't produce antibodies in some patients with illnesses that cause weakened immune systems or who take medications that suppress their immune system.

"We have not yet seen a single patient that got the vaccine even with a suppressed antibody response that has been infected with COVID," says Dr. Jeffrey Schneider, of Perlmutter Cancer Center Long Island. "So although we are concerned, and we've advised those patients to be cautious we also recognize that there may be other ways in which the immune system is protecting them without manifesting antibodies."

Nelson says, "I would like to see my daughter and her husband. I would like to see friends. I'd like to get back out into the world."

Nelson decided to get another round of the vaccine to see if that would produce antibodies. That is not recommended and could be dangerous, experts say. Nelson says he made the choice because he feels getting COVID is more of a risk for him.