Viral Diseases: Mechanisms of Emergence and Immunity

An infectious disease is the result of the interaction and battle between two living organisms, the pathogen, and the host. Understanding these diseases necessitates a study of both defence mechanisms and virulence mechanisms, as well as the evolution of both. The mechanisms of emergence and immunity of viral diseases are therefore a very complex issue. It requires a multidisciplinary approach. The virulence causing the disease is biological and involves host-pathogen interactions. Beyond the first contact between a pathogen and a new host species (primary case), there is a permanent evolution of the pathogen and of the host defences. Deciphering this dual evolutionary process is an important key to understanding the epidemiological and pre-epidemiological steps. Epidemiology focuses on the dynamics of the dispersion of the disease, but the infection of the host and the host-pathogen interactions start long before the disease per se emerges and is described. However, the compatibility of the virus and the host is not enough to trigger an epidemic. Human factors are also involved. One of the qualities that defines today’s era is the speed and magnitude at which changes occur. Most of these changes have an anthropic origin and may have an impact on viral zoonoses and, consequently, on human health. One must consider that what causes the disease is biological (the pathogen), but what causes the disease to emerge is societal (anthropogenic). A virus adapting to humans becomes "humanized" but since a virus uses the host ecology as a way of being disseminated, a human virus also becomes "socialized" since its transmission depends on human societal rules. The mechanisms of disease emergence are complex and multidimensional.

This complexity translates into antagonistic host-pathogen interactions, displaying a delicate balance of actions and counteractions between the host immune system and virus escape and virulence mechanisms. This also has an ecological dimension; the virus sometimes manipulates the behaviour and ecology of the host for its own dispersion. This, for instance, indicates viral actions in the host brain. Specific organ tropisms are very frequent. These adaptations and counter adaptations play a central role in the evolution of host-parasite relationships in the microbial world. Tight genetic interactions between hosts and pathogens lead to host-parasite coevolution. All these dimensions must be addressed in order to have a comprehensive, and as least biased as possible, view of the system.

The objective of this article collection is to offer a dedicated space for transdisciplinary and integrative works aiming at understanding the mechanisms of emergence and immunity of viral diseases such as coronavirus, phlebovirus, lyssavirus and hepatitis E virus.

For this topic, all types of articles are welcome, i.e. research articles, notes, reviews, systematic reviews concept articles. Priority will be given to transdisciplinary studies linking the various disciplines in the analysis of virus virulence and emergence, immune response of the hosts, and societal elements affecting the process of infection and disease emergence.

The scope is broad as the collection is welcoming articles bridging different specialties, disciplines and dimensions in the understanding of the mechanisms of viral disease emergence. This interdisciplinarity and integrative nature of the articles is a key element.

• Virus evolution to infect human cells

• Emergence of epidemics (epidemiology, eco-epidemiology, health sciences)

• Societal aspects of emergences (sociology, law, economics, urbanism, demography)

• Crosscutting and integrative approaches (computing, modelling)

• Actions and counteractions between host immune system and virus escape mechanisms

• Virus-host coevolution

• Ecological dimension of virus transmission (host manipulation, behavioral changes)