The WHO global influenza surveillance and response system (GISRS)—A future perspective

Hay, Alan J; McCauley, John W

Many of the advances in our understanding of influenza were made in close association with the network-the "free" sharing of viruses and information providing a vital resource for the research community. Thus, revelation of the protein composition of the virus, 4 the segmented nature of the virus genome and the structural (sequence) relationships between segments 5 in relation to genetic reassortment, and the antigenic relationships between animal and human influenza viruses, 6 as the basis of pandemics, 7, 8 were closely associated with the work of members of the WHO network and the WHO CCs in particular. Elucidation of the crystal structure of the haemagglutinin (HA) provided the first clear understanding at the molecular level of antigenic drift, 9 of different receptor specificities between human and animal viruses in relation to host range restriction 10 and the mechanism of virus entry into a cell, and more generally the mechanism of membrane fusion. 11 Other notable spin-offs from research on resistance and immunity to infection were the discovery of interferon 12 and the uncovering of the peptide basis of cell-mediated immunity. 13 It is this scientific excellence within GISRS that has provided the intellectual authority and credibility for confidence, not only in the veracity of the biannual WHO recommendations on vaccine composition, but also in the procedures/methods, guidance and interpretive tools developed to anticipate the risk from seasonal antigenic/ genetic variants and emergent zoonotic infections.