Changes

=Antigenic Shift and Drift=

=Antigenic Shift and Drift=

Flu continues to be a feared disease because of it's ability to evolve, both within a particular strain and into new and undefined strains.  The flu epidemics of history show that antigenic variation of influenza should not be taken lightly, hence the great concern over the recombination of the H5N1 virus in asia through infection of a pig with human and avian strains of flu.

*Flu continues to be a feared disease because of it's ability to evolve, both within a particular strain and into new and undefined strains

*'''Shift''' is the more serious of antigenic movements and is definied by:

*'''Shift''' is the more serious of antigenic movements and is definied by:

**Gene reassortment

**Gene reassortment