Vaccine Controlled AIDS in Monkeys

Friday, March 9th 2001, 12:00 am
By: News On 6

WASHINGTON – In a study giving new evidence that AIDS can be controlled by vaccine, inoculated monkeys stayed healthy despite exposure to high levels of virus, researchers say. The new vaccine is being fast-tracked toward human testing.

In a report appearing Friday in the journal Science, researchers said the vaccine uses a one-two-three punch, with two shots to prime the immune system to resist the AIDS virus, and a final shot with a modified pox virus to boost protection.

The first two shots use a vaccine containing DNA for three proteins like those found in the AIDS virus. These proteins create a memory that prompts the immune system to attack when the proteins are later detected, said Harriet L. Robinson, senior author of the study.

The booster shot uses a modified smallpox vaccine with the three HIV proteins added. This intensifies the immune system's response against the AIDS virus proteins, she said.

"Our results show that we can protect monkeys against an HIV-like virus using an immunization scheme that is practical for use in people," she said. Dr. Robinson noted, however, that the vaccine has not been tested for use in people already infected with HIV.

Dr. Anthony S. Fauci, head of the National Institute of Allergy and Infectious Diseases, said the study "provides some of the best evidence to date that a preventive HIV vaccine" may work.

Dr. Robinson, a professor at the Emory University Vaccine Center and the Yerkes Regional Primate Research Center, said human trials are expected in less than a year.

In the study, 24 monkeys were inoculated with varying doses of the new vaccine. Four other monkeys received only placebos. Seven months later, all the monkeys were exposed to lethal doses of a virus that mimics HIV, the virus that causes AIDS in humans.

Dr. Bernard Moss, a co-author and developer of the pox virus part of the vaccine system, said that the researchers waited seven months after the monkeys were vaccinated before exposing them to the virus.