A: Antigenic drift

Sun, 03 May 2026 09:59:35 +0000

### Understanding Antigenic Drift: Implications for Viral Evolution and Vaccine Development A: Antigenic Drift is a critical concept in virology and public health, especially in the context of influenza viruses and vaccine design. Often responsible for seasonal outbreaks and vaccine mismatches, antigenic drift refers to the gradual accumulation of small genetic mutations in viral surface proteins, primarily hemagglutinin (HA) and neuraminidase (NA). These proteins are key targets of the human immune system, and changes in their structure enable viruses to evade pre-existing immunity. --- #### What Is Antigenic Drift?