Butantan InstituteRhesus monkeys: Butantan vaccine increased the primate’s immune response 5- to 10-foldButantan Institute
Preliminary tests of a possible Brazilian HIV vaccine conducted using rhesus monkeys at the Butantan Institute have had better-than-expected results. The immune response of the primates was 5-10 times more intense than that recorded in mice, according to physician Edecio Cunha Neto, a researcher at the University of São Paulo School of Medicine and coordinator of the study. The vaccine developed by Cunha Neto’s group contains 18 fragments of the AIDS virus. The researchers’ intention is to use these fragments to awaken the immune system against HIV. “It’s like we’re helping the immune system identify the virus as soon as it enters the body,” he explains. The researchers administered three doses of the vaccine to the monkeys—one every 15 days—and saw that the animals’ defense system, which is more human-like, responded strongly. “We did tests to calculate the number of cells activated in response to the vaccine,” he says. In the first experiment with the monkeys, 3,200 defense cells per million became active against HIV. In 40 tests with mice, the best result was the activation of 330 cells per million. The encouraging results rekindle the hope that after several unsuccessful international attempts involving billions of dollars, an effective and safe vaccine against HIV might be developed.
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