Seasonal Flu Strain May Have Mutated

Canadian researchers say H3N2 virus mutated from vaccine strain
By Ambreen Ali,  Newser User
Posted May 6, 2009 2:48 PM CDT
A man has his temperature measured with an infrared thermometer at the entrance to Mexico's Supreme Court building in Mexico City, today.   (AP Photo/Marco Ugarte)
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(Newser) – A mutated version of the seasonal strain of flu targeted by this season's vaccine has surfaced in a traveler entering Canada from Mexico, Reuters reports. The development complicates the tracking of the virus in Mexico, which has suffered the majority of infections and deaths. The variant was previously found in Canadian long-term care facilities, where it may have caused an unusually late flu outbreak in March.

"We wonder to what extent the profile of influenza-like illness initially reported from mid-March in Mexico may in part be attributed to this H3N2 variant, in addition to emergence of the novel A/H1N1 virus," Canadian researchers said in a report.