A novel combination vaccine designed to treat heroin addiction and target HIV was found to elicit immune responses in mice and dull their response to injected heroin in a recent preclinical trial. Findings from the study were published today in the online journal npj Vaccines.
A team of U.S. government researchers led by scientists from the Walter Reed Institute of Research (WRAIR) created a dual vaccine formulated with three main components: a segment of a protein expressed on the surface of HIV; a synthetic molecule that resembles heroin and its degradation products; and a potent adjuvant to stimulate the immune system. Mice immunized with this vaccine had high antibody titers against the HIV surface protein as well as heroin and its derivatives.
The heroin component induces antibodies that bind to the drug in the bloodstream, preventing the drug from crossing the blood-brain barrier. “This would block the euphoria and addictive effects,” said Dr. Gary Matyas, Chief of Adjuvants and Formulations for the U.S. Military Research Program (MHRP), WRAIR. “We hope to give people a window so they can overcome their addiction.”
Since the onset of the HIV epidemic, scientists and public health advocates have attempted to curb the high prevalence of HIV among intravenous drug users. Heroin addicts in particular have a higher rate of HIV infection. In 2012, the National Institute of Drug Abuse awarded a $5 million grant to MHRP and WRAIR scientists to support the research and development of a combination heroin/HIV vaccine.
“WRAIR fosters an environment of creativity and innovation that allows us to work on novel approaches like this dual vaccine,” said MHRP’s Dr. Carl Alving, corresponding author and Chief of MHRP’s Laboratory of Adjuvant and Antigen Research. He added, “While these are very early studies in mice, we think that a dual vaccine directed to heroin—and eventually HIV— is feasible.”
Further developmental work to optimize the heroin component of the vaccine for humans is underway.