THURSDAY, SEPTEMBER 29, 2016

Converging approaches hold promise for effective HIV vaccine

Two experts from the National Institutes of Health say different scientific approaches are uniting to advance the urgent, ongoing search for an effective vaccine against the global HIV pandemic.

Specifically, those in the scientific field who advocate for an empirical approach to quash the epidemic have argued that the best way to find an effective vaccine is to test humans. Those who advocate a theoretical approach, meanwhile, have worked to understand the immune response to natural infection and how to enhance those responses via vaccination.

“Today, these approaches are coalescing into concomitant paths toward a safe and effective HIV vaccine,” Anthony Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases (NIAID), and Hilary Marston, a policy adviser for global health at NIAID, wrote in the July issue of Science magazine.

Such unified approaches are “critically needed to end HIV transmission worldwide,” according to Fauci and Marston, who take a historical perspective to delve into the situation in their article published by the American Association for the Advancement of Science, an international nonprofit.

Historically, according to the doctors, there’s been ongoing tension for decades between the desires to move quickly to clinical trials to stop the epidemic’s spread versus pro-research views into HIV pathogenesis and host immunity to inform the design of a vaccine.

“Recent advances in HIV vaccine research provided the impetus for this look back at vaccine development efforts,” Fauci told Vaccine News Daily. “These advances include identification of markers predictive of vaccine efficacy among the participants of the RV144 trial, as well as discoveries related to broadly neutralizing antibodies,” or bNAbs.

Specifically, the RV144 trial in Thailand created controversy in the field by pitting empirical and theoretical approaches against one another, the doctors said. 

For instance, those pursuing the empirical approach found that the trial demonstrated a more than 30 percent reduction in infection among vaccine recipients. Today, “investigators now seek to improve on RV144, hoping to increase the durability, potency, and breadth of responses,” according to the doctors.

At the same time, those pursuing a theoretical approach made discoveries related to bNAbs that target many HIV strains and develop naturally over time in a minority of HIV-infected people. Such work provides “an intriguing model for vaccine development,” the doctors said, though their efficacy in preventing infection remains unproved in humans. Nevertheless, scientists hope to design vaccine regimens that stimulate the immune systems of uninfected people to produce bNAbs.

Together, both approaches have influenced promising approaches and provide insight for an effective HIV vaccine, Fauci said.

“Future work will need to pursue a parallel track of trying to optimize the empirical approach by building on work started with the RV144 trial, balanced against a theoretical approach focused on devising ways to induce production of bNAbs in uninfected individuals,” Fauci told Vaccine News Daily.

With HIV, as with other viral diseases, Fauci said that a vaccine is necessary to durably end the epidemic – not just slow it down. 

“We now have a golden opportunity to expand on the recent advances in HIV vaccine research,” he said last week. “I am cautiously optimistic that we will develop an effective vaccine within a reasonable amount of time.” 

To read the article in its entirety, go online to: http://www.sciencemag.org/content/349/6246/386.full.pdf.

Organizations in this story

National Institute of Allergy and Infectious Diseases (NIAID) 5601 Fishers Lane, MSC 9806 Bethesda, MD 20892-9806

National Institutes of Health 9000 Rockville Pike Bethesda, MD 20892

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