A vaccine has been created which helps to extend survival in monkeys after they have been infected with the virus according to the journal Science on June 9. The vaccine does not cause immunity; however, researchers say it could become a treatment for humans that would let infected people live longer before becoming symptomatic.

Dr. Norman Letvin of Harvard Medical School and his research team vaccinated against simian immunodeficiency virus (SIV)—the closest possible to human infection. The monkeys which received the vaccine lived almost three times longer (900 days) with the virus then those who were not given the vaccine (300 days). Letvin said his team’s study will prove useful to researchers working with humans as it will give something for the researchers to watch for in their human subjects.

The HIV Vaccine Trail Network (HVTN) has organized several clinical studies using human volunteers in order make further progress developing DNA-based vaccines. Miriam Hospital in Providence, Rhode Island, along with health centers in Boston and New York City, are in the beginning stages of programs and are using HIV-negative human test subjects to research DNA-based vaccines. Letvin stated that there are two human vaccines that are similar to this that is now going forward into advanced efficacy trails: One by the U.S. National Institutes of Health and the other by pharmaceutical company Merck and Co.

Dr. Melissa Gaitanis, head of human research being conducted at Miriam Hospital, explained the basic concept behind the group’s work. She essentially explained that they have DNA technology where they create something similar to the genetic pieces of HIV, take the synthetic versions of proteins found inside the virus and the outer coating, and put these DNA particles in a viral vector like the Merck product, which uses adenovirus similar to the common cold. A viral vector is a method of insertion of genetic material into a person’s cells. The body sees the genetic material as a virus and reacts to the adenovirus as alien in a way which increases the reaction against those DNA particles.

Gaitanis says one of the most challenging aspects of carrying out these trials is people’s fear of getting AIDS from the tests or being stigmatized for participating. However, the trials are anonymous and she says the risk of the experimental vaccine as with other vaccines is insignificant.