Sep 10, 2012
White and black Canadians have lowest flu vaccine uptake in Canada
White and black Canadians have the lowest uptake of seasonal flu vaccine in Canada, according to a report today in the Canadian Medical Association Journal (CMAJ). Researchers studied nationally representative data from whites and 12 ethnic groups comprising 437,488 people during the 2003, 2005, 2007, 2008, and 2009 flu seasons. Ethnic minorities represented 18% of the total. They found flu vaccine uptake in Filipino (41%), Japanese (38%), and Chinese (35%) ethnic groups to be higher than in white (32%) or black Canadians (27%). "Variations in coverage levels persisted even after adjusting for other determinants of vaccine uptake, which suggests that there may be unique barriers and misconceptions influencing these groups differently," the authors wrote. They suggest designing appropriate interventions for different populations.
Sep 10 CMAJ abstract
Sep 10 CMAJ news release on the study
Ferrets also shown more susceptible to H1N1 after seasonal flu shot
Early in the fall of 2009, during the second wave of the H1N1 influenza pandemic, Canadian researchers found that people who received the 2008-09 seasonal flu vaccine seemed more likely to be sickened by the new virus. The finding puzzled many, had an impact on pandemic response in some parts of Canada, and was accompanied by reports from other groups suggesting contrary findings. The Canadian group who reported the initial findings shed new light on the topic yesterday at an infectious disease conference in San Francisco. They found the same vulnerability to the 2009 H1N1 virus in ferrets that received the seasonal flu vaccine. The group, from British Columbia and Quebec, detailed its findings at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). Researchers gave 16 ferrets the 2008-09 seasonal flu vaccine and 16 a placebo using blinded techniques, then infected the animals intranasally with 2009 H1N1. Illness symptoms were significantly greater in the animals that received seasonal flu vaccine. Lead author Danuta Skowronski, MD, an epidemiologist with the British Columbia Center for Disease Control, said the findings were consistent with human studies, but the reason is unclear and warrants further study, the Canadian Press (CP) reported. She said in the meantime people shouldn't avoid seasonal flu shots, because the findings might be unique to the pandemic setting.
Sep 9 ICAAC abstract
Sep 9 CP story
Study: Avian flu isolates from live-bird markets show antiviral resistance
Avian flu isolates collected from live-bird markets in the United States showed independent evolution toward resistance in the absence of antiviral drugs, according to a study in Influenza and Other Respiratory Viruses. US researchers conducted a phylogenic analysis of the M gene of 229 avian flu viruses from wild birds and live-bird markets to identify changes that may be associated with resistance to adamantanes, an older class of antiviral drugs. They found 27 different subtypes among the isolates, with H3N8 being the most dominant in wild birds and H7N2 in market birds. None of the isolates from wild birds showed resistance-associated mutations, but 17 collected at live-bird markets did. None of the birds had been exposed to antiviral drugs, which the authors say showcases the need for continued active surveillance.
Sep 8 Influenza Other Respi Viruses abstract