Availability of new recombinant H5N1 vaccine viruses

March 2009

New H5N1 recombinant vaccine viruses have been developed by the WHO Collaborating Centre for Studies on the Ecology of Influenza in Animals, St Jude Children's Research Hospital, Department of Infectious Diseases, USA, from A/duck/Hunan/795/2002 (Clade 2.1) and A/goose/Guiyang/337/2006 (Clade 4) viruses. These recombinant vaccine viruses are available for distribution, under a Material Transfer Agreement (MTA). As with all seasonal and A(H5N1) influenza viruses WHO has selected and used for vaccine development, the sequences of haemagglutinin (HA) and neuraminidase (NA) of the A/duck/Hunan/795/2002 strain can be found on the public website of GenBank:

And for the A/goose/Guiyang/337/2006 strain:

Institutions, companies and others interested in pandemic vaccine development who wish to receive these candidate vaccine viruses should contact either the WHO Global Influenza Programme at or St Jude Children's Research Hospital, at the address below:

WHO Collaborating Centre for Studies on the Ecology of Influenza in Animals
St Jude Children's Research Hospital, Dpt Infectious Diseases
262 Danny Thomas Place
TN 38105 - Memphis, USA
Fax: + 1 901 595 8559

Studies on antigenic properties of A(H5N1) vaccine viruses and their relation to the emerging H5N1 viruses are ongoing in the WHO Global Influenza Surveillance Network.

The Global Influenza Programme has been closely monitoring the antigenic and genetic evolution of the circulating viruses, especially human virus isolates. Countries are encouraged to share with WHO their specimens/isolates, both from humans and animals, in order to be included in the WHO's H5N1 vaccine virus selection and development, in addition to other activities of public health significance.