The NIH’s National Institute of Allergy and Infectious Diseases (NIAID) announced Monday that its HVTN 702 study in South Africa would cease its experimental vaccine regimen for Human Immunodeficiency Virus (HIV), which involved 5,407 HIV-negative volunteers at 14 sites in South Africa.
According to the release, the study began in 2016 and recruited sexually active men and women between 18 and 35 years of age. While 2,694 volunteers received the “investigational vaccine regimen” that was adapted to fight HIV subtype Clade C - the subtype most common in southern Africa - the other 2,689 participants of the study received a placebo injection.
Nearly 50% of those infected with the virus worldwide have subtype Clade C, according to research published in the Journal of Infectious Diseases.
Volunteers were administered a total of six injections over 18 months and were given the “local standard of care for preventing HIV,” which included access to oral pre-exposure prophylaxis (PrEP). If left untreated, HIV can develop into Acquired Immunodeficiency Syndrome (AIDS), which destroys sufferers’ immune systems, leaving them vulnerable to otherwise harmless infections.
However, an interim analysis published by an independent data and safety monitoring board (DSMB) on January 23, 2020, found 129 participants given the vaccine were eventually infected with HIV, and 123 who were administered the placebo got the virus during the trial period.
The NIAID agreed with the DSMB’s determination that trials should cease, as the “investigational vaccines had not shown any efficacy,” according to the NIH group. At the same time, participants from the study will remain cared for in follow-up visits.
“The people of South Africa have made history by answering this important scientific question. Sadly, we wish the answer was different,” HVTN 702 Protocol Chair Glenda Gray asserted in the release.
“An HIV vaccine is essential to end the global pandemic, and we hoped this vaccine candidate would work. Regrettably, it does not,” added NIAID Director Dr. Anthony S. Fauci. “Research continues on other approaches to a safe and effective HIV vaccine, which I still believe can be achieved.”
While advance of the disease can be slowed by treatments such as PrEP and rendered undetectable, only two people have been cured of HIV since it was discovered in the late 20th century.