MAINTENANCE. “The Covid-19 will become a seasonal disease” estimates Pierre Bessière, researcher in virology – LaDepeche.fr

La Dépêche du Midi: In the midst of the global Covid-19 pandemic, you are releasing a book on the flu virus … For what reasons?

Pierre Bessiere : It is a diagram that I appreciate because we see the species infected by influenza and how the influenza virus circulates. We have the ducks in the center and it shines everywhere. They transmit the disease to cats, dogs, whales, humans … To tell you, there are six diseases out of ten that are of animal origin and almost all viruses that appear as well. The flu is a good example to illustrate the progress of an animal virus which affects humans. With the flu, we have the perspective that we do not have on the Covid.

You say that six out of ten diseases come from animals: why are there so many?

There are a lot of animals on earth. They can accommodate a whole range of different viruses. For a disease to pass from animals to humans, there is still a luck factor. That is to say that there is such and such a virus in such an animal population which has points in common with us and which will succeed in passing. Another possibility is that the virus mutates to become adapted. Then there are human activities. When we pool different species on a live animal market, for example, it creates the opportunity for a virus to evolve. One example that I really like is the Nipah virus. This is exactly what should not be done. There has been deforestation in Asia, where oil palm crops have been established. So bats were deprived of their habitat and starved. To feed themselves, they therefore went to the level of these cultures. The problem is that there was a pig farm next door. They therefore transmitted a virus to the pigs, it evolved into the beast and transmitted it to us.

Why is the flu, unlike Covid-19, a seasonal virus?

It’s too early to tell but I think Covid is going to become a seasonal disease. We have the example of the Spanish flu: before it was a purely avian virus that has become adapted to humans. Suddenly, we had this H1N1 in 1918 which caused a pandemic because no one had antibodies. And this is what happened in 2019 with the Covid-19. And gradually, we have a collective immunity that develops. The virus then has more and more difficulty infecting people and then we go from a pandemic virus to a seasonal virus. Climatic factors also play a role.

What are the right actions to adopt to avoid a new pandemic?

From a more global perspective, live animal markets are not a good idea at all. Viruses are a bit of a parasite on our human activities. Of course, traveling and working when you’re sick is not a good idea. Stop deforestation, stop putting a chicken farm next to a pond where there are plenty of aquatic animals … But it is almost certain that we will have a new influenza pandemic in a few years. Besides that, science is evolving and many universal vaccines are in phase 3 trials which would allow less aggressive pandemics.