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A Clever Little Bugger by Yael Li-Ron
A study funded by the National Institute of Allergy and Infectious Diseases (NIAID) has recently concluded that the reason this formerly benign (or nonpathogenic) strain of the flu became deadly was a tiny genetic change in one of that virus' 10 genes. The influenza virus, some say, is one of evolution's most successful stories. For one thing, it's a cross-species virus, meaning it can migrate from birds to pigs to humans. When flu season is over for us, it may just be getting interesting among the farm animals. And the interesting thing is that during these "migrations" the flu virus keeps mutating under the influence of its host's DNA, so by the time the cycle returns to humans, it's a new strain altogether. Which is why there's a new flu vaccine every year, and often several times a year. Scientists develop vaccines for different strains of influenza as they're discovered. But sometimes, from the time a vaccine is developed in a lab to the moment flu season hits, a new strain has developed, rendering the vaccine pretty useless. So unlike other vaccines (say, polio), which prevent the development of a disease in a person, flu doesn't have a permanent vaccine because it's never the same disease twice. Our bodies can't be immune to "The Flu," only to this season's variety. But help may be on the way. Several researchers are looking into a universal flu vaccine that will help our bodies resist any new variant that comes along. The technique is called live vaccine, and its weapon is the immune system's T cells. A live vaccine, which uses a harmless form of the flu virus (modified genetically), would get the T cells to fight virus-infected cells. Today's vaccines, which use dead influenza viruses, stimulate B cells to produce antibodies but don't go after the infected cells. A live vaccine for the flu has been tested successfully on mice. Which means, if all goes well, we're next. For more news on influenza and other infectious diseases, check out the very informative site www.niaid.nih.gov. Formerly a mainland hypochondriac, writer Yael Li-Ron (www.tipx.com) enjoys great health since she moved to Hawaii. Her interest in medical research, and genetic engineering in particular, started a few years ago when a close friend was diagnosed with multiple sclerosis.
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In 1997, 18 people in Hong Kong were infected by a type of flu virus that had previously affected only pigs, chickens, geese and ducks, as far as anyone knew. Six of them died of what became known as the Hong Kong Virus (or, in M.D.-speak, influenza virus subtype H5N1). A million chickens were butchered, and the disease was halted.