MEN produce higher levels of coronavirus antibodies than women, according to the latest figures.
Covid-19 survivors are being sought to donate blood plasma as part of a major trial assessing whether it could help some of the sickest patients.
Tests have been carried out in order to decipher which patients have the most rich blood plasma, so that it can be donated to other patients who might be struggling.
It appears that men in general produce more Covid-19 antibodies than women do, with 43% of male donors having plasma rich enough in antibodies for their plasma to be included in the trial, compared with 29% of women.
Professor David Roberts, associate director for blood donation at NHS Blood and Transplant, said: "We'd still like to hear from anybody who had coronavirus or the symptoms. More plasma donors are needed.
"But we'd especially want to hear from men. We test every plasma donation and men have higher antibody levels, which means we're more likely to be able to use their plasma to save lives.
"Initially your immune system will try and fight off a virus with white blood cells. If you become more ill, your immune system needs to produce more antibodies that neutralise or kill the virus.
"Our studies, and many others around the world, show men with Covid-19 are more likely to become seriously ill than women. This makes them better plasma donors once they have recovered."
Despite the test results showing that men produce more antibodies, coronavirus has - one the whole - affected men more than it has affected women.
Antibodies are produced by the immune system when fighting off a disease. White blood cells are initially used, but if a virus is particularly strong or aggressive, the immune system develops specific antibodies to help in the fight.
Last week it was announced that anyone who tests positive for Covid-19 through the national testing programme will be asked to join a blood plasma trial.