AIDS Vaccine Candidate Appears to Completely Clear Virus From the Body
Promising animal data must be confirmed in humans (September 11)
An HIV/AIDS vaccine candidate developed by researchers at Oregon Health & Science University appears to have the ability to completely clear an AIDS-causing virus from the body. The promising vaccine candidate is being tested through the use of a non-human primate form of HIV, called simian immunodeficiency virus (SIV), which causes AIDS in monkeys. Following further development, it is hoped an HIV form of the vaccine candidate can soon be tested in humans. These research results were published in the Sept. 11 online edition of Nature.
“To date, HIV infection has only been cured in a very small number of highly publicized but unusual clinical cases in which HIV-infected individuals were treated with anti-viral medicines very early after the onset of infection or received a stem cell transplant to combat cancer,” said lead investigator Louis Picker, MD. “This latest research suggests that certain immune responses elicited by a new vaccine may also have the ability to completely remove HIV from the body.”
Picker’s laboratory used cytomegalovirus (CMV), a common virus already carried by a large percentage of the population. The researchers discovered that a modified version of CMV engineered to express SIV proteins generates and indefinitely maintains so-called “effector memory” T-cells that are capable of searching out and destroying SIV-infected cells.
About 50% of monkeys given highly pathogenic SIV after being vaccinated with the investigational vaccine became infected with SIV but over time eliminated all traces of SIV from the body.
“Through this method, we were able to teach the monkey’s body to better ‘prepare its defenses’ to combat the disease,” Picker explains. “Our vaccine mobilized a T-cell response that was able to overtake the SIV invaders in 50% of the cases treated. Moreover, in those cases with a positive response, our testing suggests SIV was banished from the host. We are hopeful that pairing our modified CMV vector with HIV will lead to a similar result in humans.”
Source: Oregon Health & Science University; September 11, 2013.