Virus latency

Virus latency (or viral latency) is the ability of a pathogenic virus to lie dormant (latent) within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection.

Overview

Latency is the phase in certain viruses' life cycles in which, after initial infection, proliferation of virus particles ceases. However, the virus genome is not eradicated. The result is that the virus can reactivate and begin producing large amounts of viral progeny without the host being infected by new outside virus, denoted as the lytic part of the viral life cycle, and stays within the host indefinitely.

Mechanism

Viral latency involves specific interactions between virus and host, where the virus modifies the host's behavior to facilitate the virus's survival. The mechanisms of latency allow the virus to evade the immune response in two ways. First, they allow the virus to avoid strong and rapid immune responses by expressing few viral proteins. Second, they allow the virus to persist in cells for long periods of time, thereby avoiding the immune response.

Examples

Examples of viruses that can exist in a latent state include Herpes simplex virus (which can cause herpes simplex), Varicella zoster virus (which can cause chickenpox and shingles), Epstein-Barr virus (which can cause mononucleosis), HIV (which can cause AIDS), and Hepatitis B virus (which can cause hepatitis).

See also

• Viral life cycle
• Viral replication
• Viral shedding
• Viral evolution