False about antigen drift ?
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.
Causes pandemic
Occurs due to mutation
Occurs more frequently
Affected by previous antibodies