Word: antigenically
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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...
Though the American and the Englishman never collaborated directly, their research has, in effect, followed the same paths since 1959. Antibodies form complex, giant molecules. Porter concentrated on those parts of the molecule that give an antibody the capacity to react with a foreign or threatening substance (an antigen) and destroy it. Using a protein-splitting enzyme called papain, Porter broke the antibody molecule into three fragments. He found that the molecule is Y-shaped. The two smaller and similar parts of the structure are the ones that are capable of combining with the antigen; the larger one lacks this...
...heavy" ones that make up the trunk. After establishing that antibodies have some flexible amino-acid chains, Edelman was able to demonstrate how the body can form different antibodies to deal with specific diseases. He also demonstrated how parts of the antibody molecule adhere to the antigen molecule, while others attack...
...patients who contracted serum hepatitis from injections of an infected blood-clotting factor. The researchers took weekly blood samples but did not find the culprit; so they deep-froze the samples and stored them. In 1968 the 15-year-old samples were thawed out and tested for the Australia antigen. The viruslike particle was found in the blood of 46 (or 74%) of the patients...
Chronic Carriers. One nagging mystery remains: If the Australia antigen is indeed responsible for hepatitis, why is it found in so many apparently unrelated conditions? Hematologists, for example, found it in only one of 1,000 blood samples from healthy Americans, many of whom may have had a mild case of hepatitis without knowing it. The antigen was found in the blood of 30% of mongolism victims living in large institutions, which are often swept by viral epidemics. It is common among leukemia patients who presumably get it through transfusions. It was also discovered in 9% of patients with...