[Diversification of influenza viruses].

Abstract

The presence of flu in humankind history was cited by numerous sources (the oldest known source was written by Hyppocrates, in 412 BC), but the epidemic impact could be measured only starting with the XVIII-th century, after the pandemics from 1729 - 1733 (with estimates of about two million deaths). Nowadays, health scientists dispenses vaccines, containing the antigenes of the viruses responsible with the flu in the last winter mixed with other two major flu-types. The effect of the current flu vaccines extends over about six months from the moment of innoculation. The reason of that short effectiveness of the vaccines is given by ability of viruses to change themselves very quickly. There are two ways through which the virus can astonish the victim antibodies (humans or animals): the mutation (named antigenic drift) and the genetic recombination of the genomic segments from different strains (named antigenic shift).