by Marie-Claude Boisvert, Chief Editor

The idea for this article came to me during a visit to my colleagues in London. Sitting side by side with one of my male colleagues, I take a step back due to his many throat clearings and coughing.

– “A real man’s flu, there’s nothing worse”, he tells me with his British accent.

– “Nothing worse??”, I replied unconvincingly.

Evolving in a masculine environment, I see two of my colleagues turn around to confirm that there was NOTHING worse than a man’s flu.

– “You make me laugh. It’s only a flu. Women manage to survive childbirth, which is literally the equivalent of trying to pull a grapefruit out of a nostril. It’s not a little flu that will kill you.”

After a big collective laugh, my colleagues look at each other in an accomplice way to try to convince me that a man’s flu is so difficult to overcome, such a scourge that it could be even worse than giving birth. Of course, they exaggerated the whole thing, but is it true that there is a difference in how the flu virus attacked men and women? I  start getting interested in the subject. How many times in my life did I hear the expression “A man’s flu”, is it based on something real?

A recent study by Dr. Francisco Úbeda and Vincent A. A. Jansen, both from the University of London, suggests that there may well be a difference in how some viruses affect men and women.

Stronger than you think

Studies show that on average, women survive in greater numbers to deadly infections. For example, men infected with Tuberculosis are 1.5 times more likely to die of the disease than their female equivalent. With respect to the influenza virus, research from Stanford University indicates that women have stronger antibodies, which gives them better protection against the virus. WE ARE STRONGER THAN WE THINK.

But why is this so? Francisco Úbeda and Vincent A.A. Jansen developed a mathematical model (biology meets mathematics) to study the transmission and virulence of different viruses by gender.

“Viruses may be evolving to be less dangerous to women, looking to preserve the female population”

Researcher Francesco Ubeda

Francisco Úbeda and Vincent A.A. Jansen’s Model

First, let’s summarize/generalize virus transmission (don’t worry, it will be quick and light). Virus transmission can occur horizontally or vertically. The virus is transmitted from one individual to another of the same generation (horizontal transmission) or it is transmitted from the mother to the fetus (vertical transmission).

The female gender, by giving life and breastfeeding, transmits their antibodies and certain viruses to the child, pathogens adapt and evolve by being less virulent for her. The results of these two researchers suggest that the virus would benefit from being less aggressive towards women in order to reduce the risk of death and increase the chances of also infecting the child (even more so for viruses with a greater vertical transmission rate). So viruses are smart?

Breastfeeding longer could allow women to build a stronger humeral system. All the ingredients are here to create a social debate. Extending breastfeeding time in the long term in order to save the lives of some women (in order to strengthen their humanitarian system) may conflict with the risk of passing infections to the child with more chance to contract her infections by breastfeeding.

Most of the data collected on the effect of breastfeeding compare Japan with the Caribbean, where breastfeeding would be longer.

These two researchers would try to model the transmission of viruses using a transmission vector. Both sexes have the possibility of transmitting the virus through horizontal transmission, but women also have the possibility to transmit the virus through vertical transmission. This model uses these characteristics to understand the difference in the virulence evolution of pathogens by gender.

This subject of study, although more intriguing, is still at the stage of first research.  Sabra Klein, who has done immune system research at the Johns Hopkins Bloomberg School of Public Health in Baltimore, discussed other causes to explain these different results. She cites, among other things, the culture of the different region, ethnicity, and many others.  As my years of mathematics taught me, there is a difference between a correlation and a causal effect (it is not because there is a strong link between two variables that one is responsible for the second). The multiple statistics tools we have can be powerful and very useful, but they must sometimes be taken with care.Here the study in detail.

Men aspired to be strong as a women

A smart virus? Although imagining a virus with a small, Machiavellian brain analyzing the likelihood of affecting as many people as possible seems unrealistic, how can pathogens detect the gender of the infected individual?

For Vincent A. A. Jansen, this question remains unanswered, but there are several kinds of hormonal differences and other transmission parameters that are singular in men and women. Once the classification mechanism used by the viruses is identified (if this is possible), the door to the manipulation of these mechanisms will be open. Researchers will be able to focus on a way to “persuade” the virus that he is in contact with a female body rather than the male one.

While researchers agree on the possibility of drug rigging with medications, Dr. Ubeda emphasizes that we are not yet at this stage and that for the moment everything is falling into place. Fantasy or science fiction.    Will men accept to play the game and rig the viruses to persuade them they are as strong as a woman;)? The whole thing will also be part of an ethical debate (always and again).

What’s Next…

Although the studies have only scratched the surface of the subject, it will be interesting to follow the developments in the coming years as to whether it will be possible to deceive the viruses on the sex of the person it affects and see the consequences of it.

In the meantime, I must abdicate and give the benefit of the doubt to my colleagues about the abomination that is a ”man’s flu” – everything must be taken with a grain of salt!