“Viruses may be evolving to be less dangerous to women, looking to preserve the female population,” Dr Francisco Úbeda, of the School of Biological Sciences at Royal Holloway, explained to The Telegraph.
“The reason why these illnesses are less virulent in women is that the virus wants to be passed from mother to child, either through breastfeeding, or just through giving birth.”
The scientists particularly looked at Human T-cell Lymphotropic Virus Type 1 (HTLV-1), which can cause leukaemia in infected individuals.
And what they found was that infected women tend to develop leukaemia less often than men when there is more mother-to-child transmission.
Death due to infectious diseases is often higher in men than in women, but it has previously been attributed to differences in the immune system of each sex.
But this new study now suggests it is the virus itself which prevents women becoming too ill.
“It has already been established that men and women react to illness differently, but evidence shows that viruses themselves have evolved to affect the sexes differently,” explains Professor Vincent Jansen, from the School of Biological Sciences at Royal Holloway, University of London.
So there you go, ladies. The next time your man moans about not feeling well, you might want to ease up on the eye-rolling a little…