17 November 2009 -- Preliminary tests reveal no significant changes in the pandemic (H1N1) 2009 virus based on investigations of samples taken from patients in Ukraine. Analyses are being performed by two WHO influenza collaborating centres as part of the global influenza surveillance network.

Preliminary genetic sequencing shows that the virus is similar to the virus used for production of the pandemic influenza vaccine, reconfirming the vaccine´s efficacy at this time.

Additional questions about the pandemic virus circulating in Ukraine will be answered as more data is available.

WHO commends the government of Ukraine for its open sharing of samples to inform global monitoring of the virus for signs of change.

A total of 34 samples were analysed independently by the WHO Collaborating Centre for Reference and Research on Influenza, Mill Hill in London, UK, and the WHO Collaborating Centre for the Surveillance, Epidemiology and Control of Influenza in Atlanta, Georgia, USA.