Availability of new H5N1 prototype strain for influenza pandemic vaccine development
The WHO Global Influenza Programme has been closely monitoring the antigenic and genetic evolution of circulating H5N1 viruses, especially human isolates. In October 2005, an observation was noted that H5 haemagglutinin (HA) genes of many newly isolated viruses from animals and humans were genetically distinguishable from the H5N1 pandemic vaccine prototype strains selected in 2004 and there was also evidence of antigenic variation among the HAs of recent viruses.
Since then, the WHO Collaborating Centres (WHOCCs) and Reference Laboratories have started developing several new recombinant H5N1 prototype vaccine strains representative of different genetic sub-groups of viruses. An H5N1 recombinant vaccine strain developed from A/Indonesia/5/2005, by the WHOCC in Centres for Disease Control and Prevention, Atlanta USA, is available for distribution, under a Material Transfer Agreement (MTA). As for all other WHO selected and developed influenza prototype vaccine strains, including seasonal and H5N1 influenza vaccines, the sequences of HA and neuraminidase (NA) of the new H5N1 recombinant stain can be found on the public Los Alamos National Laboratory database.
Institutions, companies and others interested in pandemic vaccine development, who wish to receive the prototype strain should contact either the WHO Global Influenza Programme at email@example.com or WHOCC CDC at the address below:
WHO Collaborating Center for Surveillance, Epidemiology and Control of Influenza, Centres for Disease Control and Prevention, 1600 Clifton Road, Mail stop G16, Atlanta, GA 30333, USA (fax: +1 404 639 23 34; e-mail: firstname.lastname@example.org).
The development of H5N1 prototype vaccine strains representative of viruses recently circulating in Europe and Africa is ongoing in other WHOCCs and Reference Laboratories.
At present, WHO does not recommend changing the selected H5N1 prototype strains for ongoing pandemic vaccine development. However, for vaccine research purposes, the WHO Global Influenza Programme will continue to select, verify and develop new prototype vaccine strains from genetically and/or antigenically different groups of circulating viruses, and will continue to depend on close collaboration with affected countries as regards the rapid sharing of A/H5N1 virus/specimens, both from humans and animals, and other relevant information.