New Type Vaccine Elicits Desired Response
WASHINGTON (AP) _ Researchers at Johns Hopkins University have shown that a candidate vaccine produced by genetic engineering fights the virus that produces AIDS, according to a report published Thursday.
The vaccine uses gene-splicing techniques to produce a chain of proteins mimicking a portion of the surface of the the human immunodeficiency virus (HIV), the cause of AIDS.
Vaccines against viruses usually are made of the whole virus, crippled so that it cannot cause the disease in question, or killed virus.
Writing in Science, the journal of the American Association for the Advancement of Science, the Johns Hopkins team said, ″although the induction of virus-specific ... (virus-fighting) responses is traditionally associated with attenuated live-virus vaccines, our results demonstrate that envelope protein subunit vaccines, which have greater inherent simplicity and safety, may also induce″ the desired activity.
The candidate vaccine was injected into eight volunteers four times over 18 months - an initial injection followed by three boosters.
At the end of 18 months, three of the eight had developed a response in which the cells of their immune systems attacked the HIV virus and the cells it infected.
They did so without attacking the so-called ″innocent bystander″ uninfected cells of the immune system, a major problem in AIDS research.
The test vaccine is a long way from being shown to be a possible weapon against AIDS. Further clinical tests, which could take years to complete, must be conducted before the vaccine could be used.
Other vaccines also are being tested at other labs in which portions of the AIDS virus proteins are being used to try to trigger an immune response.
The Johns Hopkins team was led by Rimas J. Orentas of the Baltimore institution’s department of pharmacology and molecular sciences and included James E.K. Hildreth, Eugene Obah, Michael Polydefkis, Gale E. Smith, Mary Lou Clements and Robert F. Siliciano.