All are true about Antigen drift except -: (A) It causes pandemic, (B) Occurs due to mutation, (C) Occurs frequently, (D) Minor antigenic changes
Answer is A. Antigenic drift the gradual sequential change in antigenic structure occuring regularly at frequent intervals. Antigenic drift is due to mutation and selection .It accounts for the periodic epidemics of influenza. REF:ANANTHANARAYAN AND PANIKER'S TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO-499