The hopes for a vaccine against HIV have been dashed as a clinical trial in South Africa has been stopped after it failed to prove effective in preventing the contraction of HIV.
As one of the biggest HIV vaccine trials in the world, the HVTN 702 study enrolled more than 5,400 people since 2016.
Last month, monitors checked how the study was going and found 129 HIV infections had occurred among the vaccine recipients compared with 123 among those given a dummy shot, according to the U.S. National Institutes of Health.
This proved the trial had failed.
“Whilst this is a significant setback for the field, we need to continue the quest for a preventive vaccine,” Linda-Gail Bekker from the International Aids Society told BBC.
The vaccine used in the trial was a modified version of the first candidate that proved to provide some protection against the virus, the RV144 clinical trial, which took place in Thailand.
The trial wasn’t stopped because the vaccine brought up safety concerns but rather the independent data and safety monitoring board found that the vaccine was ineffective in preventing HIV transmission.
Those who were participating were given the option of taking pre-exposure prophylaxis to prevent infection and instructed in the effective use of condoms. They were then checked on by those conducting the study. During the time in between they chose how to conduct each sexual encounter themselves.
“The vaccines used in this study are not made from live HIV, killed HIV, parts taken from HIV, or HIV-infected human cells. The HIV vaccines being tested are made from synthetic (man-made) copies of HIV pieces. Therefore, the vaccines cannot cause HIV infection or AIDS,” the Uhambo website explains.
There are two other major studies still underway, testing other approaches to a vaccine.
“An HIV vaccine is essential to end the global pandemic and we hoped this vaccine candidate would work. Regrettably, it does not,” NIH infectious diseases chief Dr. Anthony Fauci told Time.