Miller School Researchers Report Significant Advance in Developing Potential HIV Vaccine
A team of researchers at the University of Miami Miller School of Medicine has reported a significant advance in developing a potential vaccine for HIV using a preclinical model. In a recent study, they found that vaccinated rhesus monkeys were significantly protected against intravenous acquisition of a commonly used strain of AIDS virus.
“For the first time, we were able to see protection against a particular strain of monkey AIDS virus called SIVmac239,” said Ronald C. Desrosiers, Ph.D., professor of pathology and a renowned HIV researcher. “Much more research needs to be done before we can think about developing this for human use, but it’s a promising lead that we intend to pursue in the laboratory.”
Dr. Desrosiers was the lead author of a Miller School study, “Vaccine Protection Against SIVmac239 Acquisition,” published January 29 in the journal Proceedings of the National Academy of Sciences. Miller School co-authors were Mauricio Martins, Ph.D., assistant professor of pathology, David I. Watkins, Ph.D., professor of pathology, and Georg F. Bischof, Ph.D., Young C. Shin, William A. Lauer, and Lucas Gonzalez-Nieto, all researchers in Desrosiers’ laboratory. The study was conducted in collaboration with the Wisconsin National Primate Research Center, University of Wisconsin-Madison, and the Frederick National Laboratory for Cancer Research in Maryland.
“Vaccines have been society’s greatest weapons against viral diseases, but HIV poses a tremendous challenge for clinicians and researchers,” Dr. Desrosiers said. “When a person is infected with HIV, the virus continues to replicate in the absence of antiviral drug treatment, despite apparently strong immune responses of the host. There are also extensive variations in the strains of HIV, so a potential protection against one strain might not be effective against others.
In the new study, the Miller School research team developed a novel herpes virus that was engineered to carry an SIV genome into the monkeys, and elicit long-lasting cellular immune responses to all nine SIV gene products. Like HIV, the molecularly cloned SIVmac239 used in the study is difficult for antibodies to neutralize, according to Dr. Desrosiers. Prior vaccine approaches were not able to achieve protective immunity in these models, he added. In this case, the vaccinated monkeys were significantly protected against acquisition of SIVmac239 over a four-month period.
“Further work is needed to define the critical components necessary for eliciting this protective immunity,” Dr. Desrosiers said. “We also need to evaluate the breadth of the protection against a variety of strains, and explore how this approach may be extended to human use.”