Researchers anticipate being one step closer to the development of the HIV vaccine – using HIV. Researchers with the Maryland-based VirxSys Corporation declared their findings regarding the VRX1273 vaccine at the 6th International AIDS Society Conference on HIV Pathogens, Treatment, and Prevention held in Rome.
Non-human primates inhabit a version of HIV called SIV, and the VRX1273 vaccine is a genetically altered version of SIV. Ten infected monkeys were used for the study of which five were injected with the vaccine three times and the other five were injected with placebo over a period of 6 months. After 18 months, researchers found very low to untraceable amounts of virus in the bodies of 40% of the vaccinated monkeys.
Laurent Humeau the vice president of research and development at VirxSys said that “We are well on the path to a functional cure, at least in monkeys.”
Joep Lange, M.D., Ph.D., professor of medicine at the Academic Medical Center, University of Amsterdam, and head of the Amsterdam Institute of Global Health and Development noted that “Although this pre-clinical study is modest in terms of size, it is highly unusual to see near non-detectable levels of the virus not only circulating in the blood, but also in the reservoirs where HIV is known to replicate.” Following initial vaccination in the infected monkeys, the effect of the vaccine lasted for 2 years without requirement of any booster shots.
Similar types of therapeutic vaccines have been created by other researchers. For instance, in May, Dr. Louis Picker of the Vaccine and Gene Therapy Institute at the Oregon Health and Science University declared that a certain vaccine successfully prevented monkeys from acquiring SIV. Similar to the VirxSys vaccine, this was a genetically altered virus called CMV from the herpes family.
Although the vaccine has proved to be successful in monkeys, moving from monkeys to humans is a big leap. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, said that therapeutic vaccines “have looked really good in monkeys – but monkeys are not people and SIV is not HIV. Really good concepts in primates have been duds in people.”
A therapeutic vaccine like VRX1273 has the potential to be cost effective in dealing with HIV unlike many antiretroviral drugs in the market. VRX1273 may likely be administered several times, possibly only once during a patient’s lifetime unlike drugs those are administered for the entire duration of a patient’s life.
Humeau is of the opinion that he and his team are headed in the right direction and following approval from the U.S. Food and Drug Administration, they hope to start clinical trials in humans as early as 18 months.