Native Alaskans and Australians tend to lack potent flu-fighting immune cells
Aboriginal Australians and Alaska Natives may be particularly vulnerable to a bird flu that emerged last year in China.
Since it appeared in February 2013, H7N9 avian influenza virus has infected 147 people, including six diagnosed last month. At least 46 people have died.
When viruses infect people, immune cells known as T cells can sometimes mount a defense, provided that they’ve fought off similar invaders in the past.
Some genetic variants increase T cells’ ability to combat H7N9, and those variants are more prevalent in certain ethnic groups, Katherine Kedzierska of Australia’s University of Melbourne and colleagues report January 6 in the Proceedings of the National Academy of Sciences. Only about 16 percent of Alaska Natives and Australian Aborigines carry the flu-fighting variants; more than a third of Asians and Africans and 57 percent of people of European descent do.
In addition, Alaska Natives and Aborigines were much more vulnerable to the 1918 Spanish flu and a 2009 pandemic flu than other groups. If the H7N9 virus, which shares some characteristics with those viruses, spreads and becomes a pandemic, these groups should be at the front of the line to get vaccines, the researchers suggest.
S. Quiñones-Parra et al. Preexisting CD8+ T-cell immunity to the novel H7N9 influenza A virus varies across ethnicities. Proceedings of the National Academy of Sciences. Published online January 6, 2014. doi: 10.1073/pnas/1322229111.
T.H. Saey. Year in Review: A double dose of virus scares. Science News. Vol. 184, December 28, 2013, p. 23.