Could We Soon See a Vaccine for HIV?

By Chelsea Bailey | August 1, 2013

A T-cell infected with HIV. Researchers are getting closer to figuring out how people “naturally immune” to HIV can fend off the virus.

UC-Berkeley

Researchers may have overcome one of the biggest barriers to creating an HIV vaccine, according to new findings from scientists at the Scripps Research Institute

Scientists have uncovered a way to follow and replicate the development of an effective antibody response against HIV. By isolating and studying these proteins, scientists hope to reproduce the triggers for a strong and effective immune response to HIV – bringing us one step closer to creating the building blocks for an HIV vaccine.

“It’s not going to happen tomorrow, but something we haven’t understood about how HIV interacts with the immune system has been uncovered with this research,” said Jeff Safrit, Director of Clinical and Basic Research at the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF).

“The desire to work on finding a vaccine or discovering a cure is what drives many scientists.”

Roadblocks to creating a successful vaccine

For more than 30 years, scientists and researchers have worked tirelessly to discover a cure for HIV, but Safrit describes the process as “a huge Catch 22.”

“We’re trying to make a vaccine against something that is attacking the system that makes the vaccine work,” he said. “Immunology is incredibly complicated.”

Typically, as a disease spreads through a population, some people become infected, while others do not – their bodies are more adept at fighting off the disease and they are deemed “naturally immune.” Scientists are then able to study this section of the population and pinpoint the “correlate of immunity,” or what it is that triggers such a powerful and potent immune response in their bodies. They then replicate these triggers in labs, and distribute them in the form of vaccines.

But these patients – dubbed “long term non-progressors” or “elite controllers” by immunologists – are rare. Safrit estimates that about 1 percent of people infected with HIV are able to fight the disease without assistance from ARVs.

What’s more, it can take years for a patient to develop a strong immune response, making it difficult to predict or duplicate the intense and immediate reaction needed to create a successful vaccine. Because ARVs are so readily available, it’s become “harder to find people who might make the best immune response without taking drugs,” Safrit said.

And in the rare instance that scientists are able to find patients who are naturally able to resist HIV, they still don’t have a complete understanding of why their antibodies are different from the general population.

“We understand parts of it, but there’s not one specific thing you can point to and say, this is what causes them not to get sick from HIV. Because of that, there’s not correlate of immunity that you can use to design a vaccine,” Safrit said.

New discovery, new hope

Scripps scientists presented detailed blueprints of how HIV interacts with the immune system last week at the American Crystallographic Association Conference in Hawaii.

The hope is that the research will break down many of the existing roadblocks to creating a successful HIV vaccine.

“An effective HIV vaccine is like a holy grail for many scientists,” Safrit said. “Pursuing that cause is enough for a lot of individuals, even with all of the setbacks over the years. It’s one of those problems that no one has been able to solve, which makes it difficult, but it makes the scientific reward that much better.”

To learn more about Dr. Safrit and the EGPAF research team’s work to treat and prevent HIV, visit our research page.

 

Chelsea Bailey is EGPAF’s Communications Assistant, based in Washington, D.C.