system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
False about antigen drift?
assistant
The correct answer is  Ans. is 'a' i.e., Causes pandemic o Antigenic shift (not drift) is responsible for pandemic. o Antigenic drift occurs due to point mutation. o Antigenic drift occurs more frequently (2-3 years) than antigenic shift (10-15 years). o Antigenic drift is influenced by the presence of antibodies to the predecessor strains in the host population.