PARIS • Men infected with Covid-19 are three times more likely to require intensive care hospitalisation than women and are at significantly higher risk of dying from the virus, scientists said.

Researchers analysed more than three million confirmed coronavirus cases from 46 countries and 44 states in the US between Jan 1 and June 1.

They found that the risk of Sars-Cov-2 infection was the same for women and men, as "exactly half" of the confirmed cases were male patients.

But the men are almost three times more likely than the women to be hospitalised in an intensive care unit and are 39 per cent more likely to die from the virus, the study said on Wednesday.

The data "may help doctors to recognise that sex is a risk factor for severe disease when managing patients", Dr Kate Webb, co-author of the study, told Agence France-Presse.

"Sex is an under-reported variable in many studies and this is a reminder that it is an important factor to consider in research," the Cape Town University researcher added.

The trend is global - aside from a few exceptions - and can mostly be put down to biological differences, researchers said.

"Sex differences in both the innate and adaptive immune system have been previously reported and may account for the female advantage in Covid-19," the authors said.

Women naturally produce more type I interferon proteins that limit the abnormal immune response known as a cytokine storm, believed to play a role in provoking severe forms of Covid-19.

The "female" oestradiol hormone may also help women to fend off grave forms of the virus, as it boosts the response of T cells - which kill infected cells - and increases the production of antibodies, the study said.

"In contrast, the male sex hormone testosterone suppresses the immune system," the authors noted.

AGENCE FRANCE-PRESSE