Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, May 28, 1993 TAG: 9305280022
SECTION: NATIONAL/INTERNATIONAL PAGE: A-12 EDITION: METRO
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
Dr. Preston A. Marx of the New Mexico Regional Primate Research Laboratory reports today in the journal Science that five of six female monkeys were protected against vaginal exposure to a simian AIDS after inoculations with slowly dissolving beads coated with the virus.
"The idea with this vaccine is to neutralize the virus at the point of contact," Marx said in an interview. "Our feeling is that once the virus enters the bloodstream that the vaccine will be far less effective."
The study with macaque monkeys used a virus called simian immunodeficiency virus, or SIV, that is closely akin to HIV, which causes AIDS in humans. SIV causes AIDS in monkeys.
Marx said the goal of the vaccine was to cause the female monkeys to develop SIV antibodies in the mucous membrane that lines the vagina.
Although the majority of AIDS cases in the U.S. are among homosexual men, the disease worldwide is most commonly spread through heterosexual intercourse. On a global basis, the majority of AIDS patients are heterosexual.
For this reason, researchers believe a successful AIDS vaccine will have to trigger formation of antibodies in the mucous membrane of the vagina, and no experimental vaccine has been shown to be protective against virus spread by heterosexual contact.
Marx said that often experimental vaccines given only by injection do not produce vaginal antibodies. For this reason, he used a vaccine that is introduced into the body by a slowly dissolving, microscopic bead developed at the University of Alabama at Birmingham.
An inactivated SIV virus was mixed with the beads. This created a powder that could then mixed with a liquid and used as a vaccine, Marx said.
The researcher said that monkeys were divided into groups. One group of four received no vaccine. In the second group of four, the vaccine was given orally. A group of three received vaccine injections in the thigh followed by a booster dose that was dripped into the lungs, a process that mimics an aerosol spray, Marx said.
The last group demonstrated the most protection against the virus.
Marx said that in the monkeys that were protected, tests showed that antibodies against the SIV virus developed in the vagina.
"We found the vaginal tissue is actually bathed in antibody, and hopefully this will kill the virus," he said.
by CNB