Scripps Research Team Develops Promising HIV Vaccine

By DocWire News Editors - Last Updated: December 18, 2018

A team from Scripps Research has recently found that their experimental HIV vaccine lead to a successful immune response to the virus in primate studies. Their study involved rhesus macaque monkeys, and after vaccine administration, they produced neutralizing antibodies against an HIV strain that represents the most common form infecting humans.

Scripps Research has hosted extensive research into HIV vaccination for over 20 years, and with this new research published in Immunity, the scientists have shown an experimental vaccination to be effective in comparable animal models. This research is the first to show vaccine-induced antibody levels needed to protect one against HIV infection. The resilient viral strain observed in this study was a Tier 2 virus, resembling the virus that most commonly infects humans. This strain is referred to as such because it is clinically known to be challenging to neutralize, as are the forms of HIV present in the human population.

“We found that neutralizing antibodies that have been induced by vaccination can protect animals against viruses that look a lot like real-world HIV,” said Dr. Dennis Burton, chair of Scripps Research’s Department of Immunology and Microbiology, scientific director of the International AIDS Vaccine Initiative Neutralizing Antibody Center and of the National Institutes of Health’s Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery.

Previous research with this vaccine showed that some of the immunized monkeys naturally developed low neutralizing antibody levels, while others developed high antibody levels after vaccination. Building from this study, the researchers tested the vaccines efficacy in six of the low antibody monkeys and six of the high-level ones. 12 unvaccinated monkeys were also included in the study as a control group.

The subjects were then exposed to the SHIV form of the virus, which was engineered to contain the same envelope trimer as the virus infecting humans. This was done to ensure that the virus could still infect the primates but contain key aspects of the human virus that the vaccine was designed to target.

The team found that the vaccination worked well in the high-level antibody subjects, with these macaques creating ample levels of antibody to defend against the infection.

“Since HIV emerged, this is the first evidence we have of antibody-based protection from a Tier 2 virus following vaccination,” said Dr. Matthias Pauthner, research associate at Scripps Research and co-author of the study. “One question now is how can we get such high titers (antibody levels) into every animal?”

The focus on antibody levels is particularly significant to the researchers, as they saw protection against HIV fade as high titers dropped as time from vaccination increased. Continuous tracking of antibody levels allowed the researchers to determine the titers necessary to control HIV.

A key finding of this research was that neutralizing antibodies are central to stopping the virus, as opposed to other facets of one’s immune system. Being that other labs have largely focused on T cells and other immune defenses as key players in defending infection, Pauthner feels this is one of the studies most significant findings.

As for future implications, the researchers plan to improve their vaccine’s design and eventually conducting human trials that keep antibody titers high. “There are many immunological tricks that can be explored to make immunity last longer,” said Pauthner.

A new candidate HIV vaccine from Scripps Research surmounts technical hurdles that stymied previous vaccine efforts. https://t.co/cRqjzWF0pw submit your abstracts soon to reserve your slot #viraldiseases #virology #infectiousdiseases #tropicaldiseases #parasitology #pathology pic.twitter.com/LXS6si7V0j

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