What is the relevance of present seasonal flue vaccine (2009) in light of
the current swine flue pandemic? The present flue vaccine composition was
recommended by WHO in anticipation of the prevalent strain expected to
circulate in the flue season of this year. Because of the swine flue
pandemic, there is confusion regarding predominant prevalent strain at
A unique feature of influenza epidemiology was that
once an antigenic variant emerged, it displaced completely the
pre-existing strain. Thus, when H1N1 strains arose in 1946-47, they became
the only viruses causes human disease, and the previous H0N1 strains
disappeared completely. The H1N1 strains were displaced by H2N2 strains in
1957, and they, in turn by H3N2 strains in 1968. But this rule has not
been observed in recent years. H3N2 strains continued to be prevalent
inspite of pandemics of Hsw1N1 strains in 1976 and H1N1 strains in 1977.
So, at present is there any data/evidence which suggest
the co-existence of both the seasonal strain and the pandemic swine flu
strain?, or, is swine flu strain is the predominant strain?
If swine flue strain is the predominant circulating
strain then seasonal flu vaccine is useless and it should not be used.
What is the opinion of IAP COI in this regard?