IMMUNE EVASION STRATEGIES IN VIRAL INFECTIONS: A FOCUS ON LATENCY AND ANTIGENIC VARIATION

Zainab Adenekan*

ABSTRACT

Viruses have evolved a wide array of immune evasion strategies to establish persistence and enhance transmission despite robust host defenses. This review focuses on two central and contrasting mechanisms of viral immune evasion: latency and antigenic variation. Latency allows viruses such as herpesviruses and HIV to remain dormant within host cells with minimal antigen expression, effectively hiding from immune surveillance and contributing to lifelong infections. In contrast, antigenic variation, prevalent in RNA viruses like influenza, HIV, and hepatitis C virus, involves rapid genetic changes in viral antigens that outpace host antibody and T cell responses. Together, these strategies represent sophisticated evolutionary adaptations that undermine both innate and adaptive immunity through mechanisms such as MHC downregulation, cytokine interference, and infection of immune cells. The review examines these processes across major human viruses, discusses their molecular and immunological underpinnings, and explores the implications for vaccine design and therapeutic interventions. By understanding how viruses exploit immune evasion to persist and disseminate, we can better develop countermeasures that anticipate and neutralize these tactics.

Keywords: Viral immune evasion, latency, antigenic variation, herpesviruses, HIV, influenza, hepatitis viruses, SARS-CoV-2, MHC downregulation, immune suppression, cytokine modulation, vaccine design, broadly neutralizing antibodies, T cell immunity, viral persiste