Word: siv
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Dates: during 1990-1999
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...colleagues, including Feng Gao, husband George Shaw and Paul Sharp, set about amplifying, sequencing and analyzing Marilyn's virus. Except in the rarest cases, chimps like the sooty mangabeys never show AIDS-like symptoms. Even so, when the researchers compared the viral DNA with the three known types of SIV (simian immunodeficiency virus), they found it had a substantially different genetic makeup. And when they compared Marilyn's genetic makeup with that of other chimps, they determined that she belonged to a different subspecies than the chimps that harbor the other SIV strains; those kindred chimps live farther east...
...study, scientists from Boston's Dana-Farber Cancer Institute and Tulane University tried to infect 15 sedated monkeys with SIV, the simian cousin of the AIDS virus. To simulate oral sex, researchers dribbled an SIV solution onto the tongues of seven animals. Then, for comparison, they carefully placed SIV in the rectums of eight other monkeys. Much to their surprise, they found that it took less of the viral solution to infect a monkey orally than rectally--6,000 times less...
...what do these findings have to say about people? Exact correlations are impossible to make. SIV and HIV, although similar in many respects, are different viruses. And the scientists did not try to create the tiny tears in the lining of the rectum like those that are produced during anal sex and that increase the chance of HIV infection in humans. But generally speaking, the results support the idea that the number of HIV particles found in an infected man's semen--though not in the saliva--is sufficient to be passed on through the mouth or throat. One likely...
...vaccine that can prevent infection altogether. And that's what makes the Sydney virus so promising--and so controversial. Could HIV itself, stripped of nef and adjacent sections of genetic material, provide the basis for such a vaccine, as Deacon and his colleagues cautiously suggest? Ongoing work on SIV, the simian immunodeficiency virus that causes an AIDS-like illness in monkeys, indicates that this might be less farfetched than it sounds. Ronald Desrosiers at the New England Regional Primate Research Center has demonstrated that when the nef gene is removed from SIV, the virus no longer has the power...
This makes vaccine development extremely risky. A weakened strain of SIV that protected adult monkeys, for example, looked safe until researchers at the Dana Farber Cancer Institute in Boston showed that newborn monkeys with immature immune systems did not respond as healthy adults do. All the young primates, in fact, developed the very disease the weakened virus was supposed to prevent. For this and a host of other reasons, most AIDS researchers argue that the only prudent strategy is to concoct a hybrid vaccine, putting the key features of a disabled AIDS virus into something more benign than a retrovirus...