To halt the spread of AIDS, an Arizona State University virologist argues that researchers must turn to the last virus that science eradicated: Smallpox.
Bertram Jacobs, who studies infectious diseases at ASU’s Biodesign Institute, will assist in developing an HIV vaccine using the virus that defeated smallpox. He is receiving a share of a $15 million grant from the Bill and Melinda Gates Foundation, which last month announced it will disperse $287 million to create an HIV vaccine.
The Gates Foundation on Wednesday announced a $500 million grant to an international fund that provides AIDS assistance in poor countries.
The Geneva-based Global Fund to Fight AIDS, Tuberculosis and Malaria will receive the grant over five years.
The gift dwarfs the $150 million the charity already has given since the Global Fund was created four years ago, and the additional $287 million the foundation announced last month.
Jacobs’ lab is charged with designing a virus that will carry HIV genes. The viruses used to vaccinate are called “vectors” and work by causing the body’s immune system to attack. In doing so, the body gains immunity to the virus the vector is carrying.
This tactic has, to date, fallen short against HIV. The problem was with the weapon, Jacobs said, not the tactic.
“Where we’ve failed in the past, we’ve tried to use vectors that are so safe that they weren’t effective,” he said.
While vectors are used to protect the body, they are still viruses that might cause sickness. So researchers have used vectors that carry an extremely low risk of disease, which the immune system essentially ignored.
Jacobs’ pox vector, however, is likely to get the body’s attention, he said.
“We’ve given up a little bit in safety,” Jacobs said, but quickly added, “not much.”
To test it, Jacobs injected the vector into a mouse with virtually no immune system. The mouse never grew ill.
The next step is to develop a strain to work for humans.
For 25 years, researchers have been unable to develop an HIV vaccine as the virus killed millions of people worldwide and continues to ravage Africa. UNAIDS, the United Nations HIV/AIDS program, estimates that 4.1 million people were infected last year.
Repeatedly, politicians and scientists have predicted that a vaccine would be in clinical tests within a few years, signaling that an end to the disease could come within a decade.
That end never materialized for many reasons, said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, the most significant being that HIV has outmaneuvered those trying to stamp it out.
“We can talk about financing, which has been an issue. We can talk about prioritization and political commitment. We can talk about community involvement in research — all of which are true and all of which have challenges,” Warren said. “But the single biggest challenges have been scientific.”
Once researchers have a vaccine that has worked on animals, testing on humans has proven long and laborious. Unlike a flu vaccine, scientists cannot determine its effectiveness in a single year, said Dr. Richard Koup, chief of the immunology lab at the National Institute of Allergy and Infectious Diseases in Maryland.
HIV infections happen infrequently — compared to airborne viruses — and must be tracked in a high-risk population over at least three years, Koup said. “It’s almost impossible, even if you have something that you’ve shown is safe and immunogenic, to then know very quickly if it’s (effective).”
- The Associated Press contributed to this report