Promising HIV vaccine trials to begin
South African effort is first in nearly a decade
VERULAM, South Africa — After decades of shadowboxing with the human immunodeficiency virus, researchers were encouraged four years ago when a test of a vaccine on 16,000 people in Thailand turned up a previously unknown vulnerability in the resilient pathogen.
The vaccine was only 31 percent effective and wore off over time, so it could not be approved for use in a general population. But the study’s results allowed scientists to exploit the chink in HIV’s armor, reformulate the drug and bring it back for another clinical trial.
Now all eyes are on South Africa, where researchers will begin inoculating thousands of volunteers Monday in the latest — and, some say, most promising — effort to develop a vaccine that prevents the disease. It is only the seventh full-scale human trial for a virus that infects more than 2 million people and kills more than 1 million every year.
“If this study shows efficacy … this would be a tectonic, historic event for HIV,” said Nelson L. Michael, director of the U.S. Military HIV Research Program, which led the Thailand study.
Should the vaccine prove to be 50 percent to 60 percent effective, experts say, that would be sufficient for drugmakers Sanofi Pasteur and GSK to begin licensing negotiations with the South African government. While such a rate is well below the acceptable margin for other vaccines, it would still make this one worth producing here — given that nearly 1 in 5 people are infected.
And an agent that works in South Africa could be adjusted later for use against viral subtypes that circulate elsewhere, including in the United States.
“Given that right now we have nothing, we’d be happy if this vaccine were even 45 or 50 percent effective,” said Gita Ramjee, director of the HIV Prevention Research Unit at the Medical Research Council in Durban, which is running two of the 15 trial sites. “Even a modestly effective vaccine like that would have a huge impact here.”
Though HIV has faded from the headlines since the development of antiretroviral drugs made the disease manageable, it is still a pandemic. About 36.7 million people worldwide were living with HIV in 2015, including about 2.1 million who were newly infected, according to the Joint United Nations Program on HIV and AIDS. In the United States, the Centers for Disease Control and Prevention says 1.2 million people are infected.
There is no preventive drug and no cure. Yet this is the first new human HIV vaccine study in about a decade.
“We need to test more vaccines,” said Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston. “In over 35 years of the epidemic, we’ve only tested four different HIV vaccine concepts. We need more shots on goal.”