by Jon Cohen
With reporting by Martin Enserink.
Although the world’s attention is focused on the novel H1N1 virus causing the swine flu pandemic, H3N2, a seasonal strain of influenza, has popped up in many East Asian countries—and some variants in circulation may outfox the seasonal vaccine in use. “We have seen that H3N2 viruses have been in fairly broad circulation in some of the countries there,” Keiji Fukuda, special adviser on pandemic to the director-general of the World Health Organization, said at a press conference today.
The H3N2 strain is one of three in the seasonal influenza vaccines. But if the H3N2 strain in circulation differs substantially from the one used to make the vaccine, the vaccine may offer less protection, and more people will get sick than usual. “For the current H3N2, we don't have such studies, so I can't tell you right now the degree the current seasonal vaccine will protect against the H3N2 virus,” Fukuda says.


