Forty-two percent of people have blood type A, and Hilary said they are more likely to need a ventilator or oxygen.
But, he added, more research is needed and we would need a control group to prove that this is the case.
“It’s really interesting, I asked many of my medical colleagues about the genetic predisposition of some people to develop severe symptoms and die,” he said.
“We studied genetics to see what makes people more sensitive, why are BAME people more sensitive, is it more exposure, or are they genetically predisposed?”
“The idea that if you belong to blood group A, you are more likely to need oxygen and ventilation and to have more severe symptoms is interesting.
“And if you are of blood group O, you are more protected, that is 44% of the population.
“We don’t know if that’s true because we didn’t have a cohort of people to study who had less severe symptoms compared to the group who had more severe symptoms, so we have to do it.
“But we don’t know if it’s the biology of the blood itself that is the underlying factor, or if it’s the genes that determine your blood type that have other effects on the body.
“The scientists invested their money in chromosome six, where high immunity is linked, to suggest that it could be the link, but that did not turn out to be the case.
“They also looked at the AC2 receptors on the cells through which the virus enters the body, and that doesn’t seem to be a factor either.
“So we are not wiser, but a lot of work is underway,” he concluded.
* Good Morning Britain aired on weekdays on ITV at 6 a.m.