A vaccine designed to fight or prevent HIV infections and spur further research in the fight against AIDS was pulled from testing in San Francisco and elsewhere Thursday after researchers found it didn’t prevent the spread of the virus.
Researchers had hoped the vaccine would prevent new HIV infections as well as reduce the viral load of patients who did end up contracting the disease. But it failed to do either.
“It didn’t work,” said Dr. Anthony Fauci with the National Institutes of Health, which led the study. “Does it or does it not prevent infection? If it doesn’t prevent infection does it have any impact on the level of virus? It didn’t.”
As a result, no further vaccines will be administered. The study was conducted in 21 cities, and included 215 San Francisco men and transgender individuals who have sex with men.
Slightly more patients who received the vaccine subsequently contracted HIV than did people who received the placebo. Fauci called that development disturbing, and said the next step of the research will be to see why that increase happened. But the difference wasn’t statistically significant, meaning it may be due to chance.
The study, which began in 2009, gave half of the 2,504 patients a series of three shots over the course of eight weeks and a fourth shot after six months. Overall, a total of 71 people tested positive for HIV during the course of the study.
After receiving the first three shots, at which point the vaccine was considered live, 27 vaccine recipients tested positive for HIV while 21 people who received the placebo tested positive, according to data analysis.
The drug was not intended to be licensed for use if it was successful. Instead, the NIH said it would “answer important scientific questions that could lead to the discovery and development of new and improved HIV vaccines in the future.”
It typically takes years to test and administer the clinical trial of a vaccine to be sure that it’s safe for use by the public.
Though this vaccine didn’t do what researchers hoped, it still provides vital information for the future of HIV prevention research, said Dr. Susan Buchbinder, director of Bridge HIV, a research, prevention and education organization operating clinical trials within the San Francisco Department of Public Health.
“As we learn more information we try to revise each vaccine,” she said. “And that way we inch closer toward a more effective vaccine.”
There are currently seven other HIV studies being conducted at Bridge HIV.