Influenza vaccine strain selection and recent studies on the global migration of seasonal influenza viruses.
Annual influenza epidemics in humans affect 5-15% of the population, causing an estimated half million deaths worldwide per year [Stohr K. Influenza-WHO cares. Lancet Infectious Diseases 2002;2(9):517]. The virus can infect this proportion of people year after year because the virus has an extensive capacity to evolve and thus evade the immune response. For example, since the influenza A(H3N2) subtype entered the human population in 1968 the A(H3N2) component of the influenza vaccine has had to be updated almost 30 times to track the evolution of the viruses and remain effective. The World Health Organization Global Influenza Surveillance Network (WHO GISN) tracks and analyzes the evolution and epidemiology of influenza viruses for the primary purpose of vaccine strain selection and to improve the strain selection process through studies aimed at better understanding virus evolution and epidemiology. Here we give an overview of the strain selection process and outline recent investigations into the global migration of seasonal influenza viruses.
Russell
Colin A
CA
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom.
Jones
Terry C
TC
Barr
Ian G
IG
Cox
Nancy J
NJ
Garten
Rebecca J
RJ
Gregory
Vicky
V
Gust
Ian D
ID
Hampson
Alan W
AW
Hay
Alan J
AJ
Hurt
Aeron C
AC
de Jong
Jan C
JC
Kelso
Anne
A
Klimov
Alexander I
AI
Kageyama
Tsutomu
T
Komadina
Naomi
N
Lapedes
Alan S
AS
Lin
Yi P
YP
Mosterin
Ana
A
Obuchi
Masatsugu
M
Odagiri
Takato
T
Osterhaus
Albert D M E
AD
Rimmelzwaan
Guus F
GF
Shaw
Michael W
MW
Skepner
Eugene
E
Stohr
Klaus
K
Tashiro
Masato
M
Fouchier
Ron A M
RA
Smith
Derek J
DJ
D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control*
D007252:Influenza Vaccines