After more than three decades and millions of deaths, researchers may be one step closer to creating an HIV vaccine.
This month, the Institute for Human Virology at the University of Maryland School of Medicine in Baltimore launched the first phase of clinical trials for a new treatment. The immunogen, known as the Full-Length Single Chain (FLSR), could potentially induce protective antibody responses to HIV-1 strains, going where previous trial vaccines have fallen short.
“Maryland is one of the top science, bio-health, and research regions in the country and is home to some of the most brilliant minds in the world,” Maryland Lt. Governor Rutherford said in a statement announcing the new trials. “I am especially proud to help announce this first phase of a potential HIV vaccine that is being developed by a talented team at UMD. The Hogan administration will continue to place a priority on supporting the Maryland universities, start-ups, and institutions that are making these groundbreaking discoveries.”
When HIV strikes, it attacks the immune system’s T-cells. No cure for HIV/AIDS currently exists and researchers have noted that, even with the ongoing trial, much more work needs to be done before the vaccine hits the market for widespread use. Though antiretroviral drugs can target active forms of the virus, it has yet to be confirmed how they fare against its inactive counterparts.
Scientists say the new FLSR immunogen could contain the HIV surface protein and stop it from joining another attachment that often makes infections undetectable. This new vaccine, if proven effective, would be taken once or twice a year, less often than what’s required of the traditional antiretroviral cocktail treatment. The human trial follows extensive studies conducted on monkeys and efforts to collect funding to develop the drug into a human-grade vaccine.
Previous trials involving monoclonal antibodies — made from immune cells — have shown that the body can defend itself against HIV, perhaps explaining why some people don’t show symptoms years after contracting the virus. Notable trials include one by the name of RV 144 that took place in the early 2000s. By the end of that decade, researchers announced positive results, concluding that the vaccine batch could reduce the risk of HIV infection among a largely heterosexual population. That discovery laid the foundation for additional research.
Even so, hurdles exist in pinning down the ideal HIV treatment. Shortly after the string of announcements about people cured of HIV in 2013, researchers found that dormant HIV lingered in the body after treatment. These viruses, named proviruses, proved more dangerous because they could get reactivated and act more potently against the immune system. Until that time, scientists didn’t know the size of the dormant pool. The discovery, reported in the journal Cell, showed that the virus could be treated, but not cured.
“The findings suggest that there are a lot more of these proviruses that we have to worry about than we thought,” study leader Dr. Robert Siliciano, from the Howard Hughes Medical Institute in Maryland, told the Daily Mail. “It doesn’t mean that it’s hopeless, but it does mean we need to focus on getting an even clearer idea of the scope of the problem.”
These situations call into question the certainty that researchers will ever find an effective HIV treatment, an effort that costs nearly $845 million annually.
In these clinical trials, patients often received powerful anti-HIV regimens that most people don’t start until years after infection. This often stems from the high cost of HIV treatment. With the cocktail of medications and doctors’ visits required, the more than 1.2 million HIV-positive adults in the U.S. have to navigate a system, oftentimes without adequate health care coverage.
Partly because of these barriers to care, French investigators recently predicted that only 15 percent of patients who receive early treatment will likely see the dramatically positive results delivered in the cases of the patients who were thought to be “cured.” For instance, after a Mississippi baby was later found to have HIV again after initial reports of a “cure,” the news incited some commentary about the lack of quality health care for the HIV-positive mother.
Though it has yet to be seen what will come out of the current HIV vaccine trial, there seems to be some agreement that swift application of treatment after infection could significantly reduce the size of HIV’s presence. However, accounting for dormant HIV proviruses that can persist in the depths of body tissue can prove to be difficult. With more than 60 versions to account for, researchers will have to ensure that they can eliminate them with this vaccine.
“While we still have more important basic research to do to crack the antibody protection challenge, this first step is an important one for us to learn how people (rather than test animals) respond,” Robert Gallo, leader of the research team, said in a statement.