False about antigen drift ?: (A) Causes pandemic, (B) Occurs due to mutation, (C) Occurs more frequently, (D) Affected by previous antibodies
Answer is A. Ans. is 'a' i.e., Causes pandemic Antigenic shift (not drift) is responsible for pandemic. Antigenic drift occurs due to point mutation. Antigenic drift occurs more frequently (2-3 years) than antigenic shift (10-15 years). Antigenic drift is influenced by the presence of antibodies to the predecessor strains in the host population.