Virus-Cell, Virus-Microbe, and Virus-Host Interactions

A virus is an infectious microorganism composed of a nucleic acid (DNA or RNA) covered by a protein coat. A virus cannot replicate on its own; rather, it must infect cells and utilise the components of the host cell to replicate. Viruses frequently result in the death of the host cell, causing harm to the host organism. Examples of well-known viruses that cause human disease are AIDS, COVID-19, measles, and smallpox.

Virulence is the degree of pathogenicity of a pathogen (bacteria, fungi, or viruses) and is determined by the pathogen's capacity to penetrate and proliferate within the host.

Viruses continue to be a major contributor to the global burden of illness via acute and chronic infections that have a significant economic impact in addition to causing an increase in mortality and morbidity. Despite the enormous progress in our understanding of the antiviral immune response and the accessibility of therapies, the prevalence of existing and novel viral infections, particularly in developing nations, is on the rise. Antiviral resistance of hepatitis C virus (HCV), influenza A virus (IAV), herpes simplex virus (HSV), human cytomegalovirus (HCMV), and human immunodeficiency virus (HIV) is a major problem. Multiple processes, including polymerase infidelity, contribute to the accumulation of mutations in the viral genome, which is one of the primary causes of rising resistances. In light of this, the World Health Organization (WHO) and the United Nations have advocated for a more effective control of viral illnesses.

Virus-host interaction is defined as the process by which viruses sustain themselves within their host species on a molecular, cellular, and population level.

Virus–host interaction is a complex phenomena that is frequently virus- and host cell-specific.

The study of virus–host cell interactions encompasses the entirety of virology and provides some of the most crucial insights into this discipline. As viruses are intracellular parasites, they rely on their host cells for the energy, macromolecular synthesis machinery, and workbenches necessary for genome replication and particle assembly. Consequently, viruses have evolved a vast array of ways for exploiting normal host cell activities. This exploitation is frequently accompanied with damage to the host cell, which may be one of the primary causes of the pathology and disease induced by viruses.

Our understanding of animal viruses has expanded dramatically during the past few decades. These advancements have led to a thorough understanding of the structure and makeup of the viral genome and the virus particle, as well as the replication mechanisms employed by viruses and the regulation of viral gene expression during infection. Understanding the virus's growth cycle has proven to be easier than understanding the virus's interaction with the host cell.