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What is Influenza pandemic is due to and explain in detail?
Ans. a (Antigenic shift). (Ref. Anantanarayan, Microbiology, 4th/pg.487)TermCommentsAntigenic drift- Gradual sequential change at frequent interval i.e. mutation of pathogen (e.g. Influenza A), such that the surface antigens differ from those of previously existing strains.- Accounts for small epidemics.Antigenic shift- Sudden drastic discontinuous change in antigenic structure i.e., by recombinant DNMA technology. - Accounts for major epidemic and pandemics.