Word: strains
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Dates: during 1970-1979
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...virus is notorious for its frequent mutations. About every ten years, on the average, the transformation is so marked that the antibody system of a person who has been infected with the most recently prevalent strain, or vaccinated against it, does not recognize the new one. So he has no immunity...
...immune to the radically different "Asian A2" and Hong Kong strains that erupted in those years. The Pasteur scientists do not claim to have anticipated such a major mutation. But in between such large alterations, the virus undergoes a process called "antigenic drift," in which subtle changes occur in the virus' protein overcoat. The now prevalent London flu strain represents one of several such minor changes in the basic Hong Kong virus of 1968, and generally available vaccines are only 50% effective against...
Forced Evolution. Until now, a vaccine to combat a newly evolved strain could be prepared only after the event (TIME, Aug. 21). Ideally, as Professor Claude Hannoun explained it, scientists would like to anticipate all the antigenic changes that nature might make in the next few years in the virus' protein coat. But how to anticipate nature? That would require capturing all the Hong Kong derivative strains now available, growing them in the laboratory and attacking them with different types of antibody. Most would be neutralized, but in this artificial equivalent of the Darwinian process of natural selection...
...devised by Australian Immunologist Fazekas de Saint Groth, his research team had artificially caused such mutants to evolve. He was confident that they had anticipated all the minor changes that nature could produce in the next five years. Thus, he claims, they have produced a vaccine effective against all strains that may develop naturally from now until about 1978. Samples prepared before the London flu strain emerged, he said, had proved 84% effective in tests on human subjects...
Democratic and Republican speakers differed on the degree of strain between the White House and Capitol Hill. The G.O.P.'s Hugh Scott dismissed it as no more than "a degree of incivility." He added: "Nobody likes to be balanced, much less checked...