23. In the evolution of influenza viruses, xtwo
key mechanisms contribute to viral diversity:
antigenic shift and antigenic drift. What
distinguishes these two processes in terms of
their impact on viral strains and the potential
for pandemics?
A. Antigenic shift results from minor genetic
changes and can lead to the emergence of new
strains, while antigenic drift involves major
genetic reassortment and can trigger
pandemics.
B. Antigenic drift involves the exchange of
genetic material between two different viral
strains, while antigenic shift results from
gradual genetic mutations within a single strain.
C. Antigenic shift results in minor changes in
viral surface proteins, while antigenic drift leads
to the abrupt replacement of hemagglutinin or
neuraminidase proteins.
D. Antigenic drift involves the replacement of
one viral strain with another in a single host,
while antigenic shift allows for the simultaneous
infection of multiple host species.
E. Antigenic shift is responsible for seasonal
variations in influenza strains, while antigenic
drift causes the emergence of entirely new
subtypes with the potential for global
pandemics.
