By Christopher Kane
The 2018 International AIDS Conference is underway from July 23 to 27, right on the heels of some exciting developments in the research world.
A pair of new studies with non-human primates and people found an experimental HIV vaccine could potentially offer lifelong protection against many of the different strains of the virus, CNN reported on July 7, 2018.
In a randomized, double-blind, placebo-controlled trial, the vaccine induced an anti-HIV immune response in 393 people and, in a parallel study, protected 67 percent of research monkeys against infection with a related virus, called SHIV (simian-human immunodeficiency virus).
Authors of the study, which was published in The Lancet, caution that additional research is necessary to determine whether the vaccine can safely and effectively immunize human patients against HIV. Still, the findings signal an important step forward in the decades-long search for a treatment that could save millions of lives.
In 1984, eleven months after HIV was first discovered, Secretary of Health and Human Services Margaret Heckler announced a vaccine would be made available within two years. “That turned out to be totally incorrect,” she later acknowledged in a 2006 interview with PBS.
From that time until 2016—the most recent year for which statistics have been compiled—AIDS has killed 35 million people. And despite significant progress in prevention, diagnosis, and treatment, the Centers for Disease Control and Prevention (CDC) estimates that about 1.8 million new cases of HIV were diagnosed in 2016, at which time nearly 37 million people were living with the disease.
Over the years, research with non-human primates has led to lifesaving therapies, beginning with the discovery of AZT, the first drug approved for treating HIV, which was introduced in 1987. Newer medications, many developed with rhesus macaque monkeys, have drastically improved health outcomes for patients—increasing life expectancies and decreasing transmissibility of the virus from pregnant women to their fetuses or newborns.
More recent breakthroughs include the introduction in July 2012 of pre-exposure prophylaxis (PReP). Studies with primates concluded a once-daily oral medication regimen, consisting of drugs used to treat HIV, substantially reduced the risk of infection with SHIV. With animal models, researchers gauged the optimal dosage ranges and found the most effective combinations of two antiretrovirals: tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC). Thanks to this work, and following the success of human clinical trials, the Food and Drug Administration (FDA) approved PReP as a preventative treatment for HIV-negative patients. If taken as directed, PReP can reduce the risk of HIV infection by as much as 99 percent.
Still, challenges with medication adherence, as well as the lack of availability and access, have persisted—especially in developing countries. The number of new HIV cases diagnosed each year around the world remains alarmingly high. Public health officials maintain that the best way to curb the rate of infection and reduce the number of deaths caused by complications of HIV/AIDS will be the discovery of a safe and effective vaccine.
On this front, research with non-human primates will continue to play a significant, lifesaving role.