The team of researchers observed that death figures in countries where men have shorter ring fingers were up to a third higher. The experts explained that the ring finger length is conditioned by the amount of testosterone the person comes in contact with as a foetus.
It is therefore believed that the longer the ring finger, the more testosterone the male has been exposed to at that stage, according to experts.
Testosterone is thought increment the number of ACE-2 receptors in the body, protecting it against the severeness of the disease.
Lead researcher Professor John Manning, said this may give Australia, New Zealand, Austria and East Asian countries, where male ring fingers are longer, “a biological advantage,” The Sun reports.
He added: “Our findings may be men with long ring fingers will experience mild symptoms and could return to work.”
The researchers said that finger length is an indicator of how much testosterone a foetus was exposed to while growing.
Professing Manning said: “The theory is that someone with high prenatal testosterone — and a long ring finger — has greater levels of ACE2.
“These concentrations are large enough to oppose the virus.”
Cell receptors called ACE-2, which cover the outer layer of cells, are what the virus latches onto in order to invade the cells.
It is believed that the larger the amount of receptors, the more access points there are for the coronavirus.
“The down-regulation of ACE-2 may therefore be associated with poor prognosis from Covid-19.
“Research suggests that testosterone in men (and estrogen in women) up-regulates ACE-2.”
The paper concludes: “A strong positive association between male 2D:4D (digit ratio) and mortality may provide a biomarker for male Covid-19 susceptibility and identify those for whom it would be advisable to exercise social distancing.”
A recent research revealed men with low testosterone levels that are infected with coronavirus face a far greater risk of dying from the disease, the study showed.
Samples from the 45 coronavirus patients in a German hospital were tested for 12 hormones such as testosterone and dihydrotestosterone.
Professor Gülsah Gabriel from the Leibniz Institute for Experimental Virology in Hamburg, who took part in the investigative efforts, told MailOnline: “The majority of male Covid-19 patients had low testosterone levels.
“Of those male Covid-19 patients who died, the majority also had low testosterone levels.
“Thus, low testosterone levels in men seem to be a risk factor for severe and even fatal disease outcome in men upon infection with so-called ‘cytokine inducing’ respiratory viruses.”