Tuesday, December 13, 2022
For a virology based on interdisciplinarity
Theme 1
For a virology based on interdisciplinarity
Christian Bréchot
Professor, University of South Florida, President of the Global Virus Network, United States Former Director General of Inserm and the Pasteur Institute and Vice-President of the Mérieux Institute
The importance of virology has recently become evident; epidemics and pandemics due to the Ebola, Zika, and Chikungunya viruses, then, of course, coronaviruses, SARS-CoV-1 followed by MERS-CoV and, finally, SARS-CoV-2, and, even more recently, the Monkey Pox virus, while waiting for the next ones… have simply reinforced a notion that the AIDS (acquired immunodeficiency syndrome) pandemic, due to HIV (human immunodeficiency virus), should have anchored much better in our minds and translated into scientific and political strategies. We know that these emergences and re-emergences are largely linked to profound changes in the human ecosystem and the planet. But we have not given ourselves the capacity to take care of them well enough, by recruiting the scientists, doctors, and specialist public health experts we need.
This is not just a French problem; it is a trend that we are seeing all over the world, including in the United States, a problem largely linked to the naive and simplistic view of many politicians, but also, unfortunately, of scientific and medical decision-makers, that the major challenge of the future is only that of "chronic" diseases, cancers, metabolic diseases, neurodegenerative diseases, for the most part.
This view and this way of "opposing" different disciplines is clearly erroneous and dangerous. In the case of virology and chronic diseases, chronic infections, such as those due to acquired immunodeficiency viruses or hepatitis B and C, have become chronic diseases; moreover, viral infections are implicated in diseases considered "non-communicable", such as cancer (between 15 and 20% of cancer cases worldwide); moreover, although these subjects remain highly debated, chronic infections by viruses of the Herpes group could be implicated in cases of neurodegenerative diseases, such as Alzheimer's disease.
Research into solutions to these problems is therefore obviously essential: diagnosis, prevention (including the search for new approaches to vaccination) and antiviral treatments. But we can only understand virology by analyzing all viruses, obviously in animals, since the impact of zoonoses (transmission from animals to humans) is now well recognized, but also by looking at bacteriophages, as well as viruses present in the oceans and soil. It is in this context that the Covid-19 crisis ( coronavirus disease 2019) has clearly shown our lack of skills in all these areas [ 1 ] ( → ).
(→) See the Editorial by C. Bréchot, m/s n° 12, December 2020, page 1107
So, how do we proceed? By increasing budgets and the number of researchers and doctors recruited? Certainly, but not only that; it's about training, among students and then researchers and doctors, a new generation of virologists who can contribute to an integrated vision of this discipline.
This is well illustrated in this issue of Medicine/Science . The various articles that can be read there provide this integrated vision, by analyzing viruses in the oceans as well as on land, their impact on animals as well as on humans, and by examining the major biological mechanisms that govern their evolution.
Let us take the example of the influence of the environment, climate change and pollution of our planet on nutrition, human health and viral pandemics, with the role played by microbiotas. It is indeed clear that the risk of future viral pandemics has been profoundly increased by changes in the animal and human ecosystem; it is also clear that nutrition plays a very important role in the susceptibility of individuals to viral infections (as well as bacterial and fungal); finally, it is increasingly evident that the disruptions of microbiotas induced in the oceans and soil by environmental changes have a significant impact on the quality of plants and therefore on that of nutrition; the circle is then finally closed by the impact of this nutrition on the human intestinal microbiota. This does not only concern bacteria and the "bacteriome", but also viruses and the virome. Many studies have indeed demonstrated the disruptions of the intestinal microbiota during viral infections. A very current example is that of Covid-19: the intestinal microbiota of infected patients is clearly modified, with an increase in populations of bacteria with a "pro-inflammatory" effect, and the importance of these disturbances is correlated with the severity of the disease and, possibly, with the occurrence of long Covid. Cause or consequence? This is the issue that needs to be addressed, in particular by intervening on the intestinal flora by transplanting intestinal microbiotas from healthy subjects, first in preclinical models, then, possibly, in humans, as well as by rigorously analyzing the real effects of these pre- and probiotics. This goes beyond the manipulation of the bacterial microbiota, and the human virome is certainly a very important element to analyze; it is indeed clear that it is a determining factor in all disturbances of the microbiota and must therefore be taken into account from now on. This is therefore a good example of future, interdisciplinary avenues in virology.
Each of these themes is already being addressed in research laboratories, but too separately, and an integrated view, which would truly enable us to identify real avenues for intervention and prevention in the future, remains to be developed. Will each researcher be able to contribute, individually, to this integrated vision? Probably not, and this underlines the fundamental importance of developing in virology, as in many other disciplines, multidisciplinary networks, combining biology, medicine, mathematics, epidemiology, health ecology, etc., which, complementary to the efforts of major national and international funding institutions, can and must contribute to this interdisciplinary "spirit" and to new, faster and more responsive modes of cooperation and training.