A ProMED-mail post (August 2, 2009)

Hong Kong’s health authorities announced Wednesday [27 Jul 2009] that a new variant of the H3N2 seasonal influenza virus has been found in the city. The Brisbane strain has been the prevalent circulator of H3N2 in the past year, and the new variant is its direct descendent, said Thomas Tsang, controller of Hong Kong’s Center for Health Protection (CHP). “However, it has some genetic changes distinguishing it from the old Brisbane strain,” he said. He said it is normal for viruses to go through changes, adding that overseas health authorities, including those in Canada, Britain and Australia, had also found the new variant.

Tsang said although vaccines provided for the northern hemisphere may not be a direct match for this new variant, they will still provide some protection against it. Noting that vaccines will be widely available in Hong Kong in a month, Tsang appealed to high-risk groups, such as those with chronic diseases, the elderly and children, to get flu shots.

According to the CHP, H3N2 accounts for 43 percent of flu viruses circulating in Hong Kong, while A/H1N1 accounts for 49 percent.