Major HIV vaccine trials kick off in South Africa after 7-year break

HIV-positive members of a self-help group pray at the start of a meeting in the village of Michelo, south of the Chikuni Mission in the south of Zambia. © Darrin Zammit
Still in the midst of a global HIV pandemic, scientists have shifted their focus to a vaccine that didn’t work seven years ago, but proved HIV prevention is possible. South African trials have now raised hopes that a modified miracle vaccine will be found.

The trial is to be the first to test an HIV vaccine in seven years. It will be carried out on South African adults – 5,400 men and women – and be the largest and most advanced trial of its type in the country, where 1,000 people are infected daily.

The current vaccine, dubbed HVTN 702, is a modified version of a previous one, which was itself a combination of two older ones.

Seven years ago, 16,000 people in Thailand tested a vaccine with a mediocre 31 percent success rate.

However, it did prove one thing: HIV can be prevented with a vaccine, however modest the success rate.

Monday’s trial will be the seventh ever to be conducted on humans.

“If deployed alongside our current armory of proven HIV prevention tools, a safe and effective vaccine could be the final nail in the coffin for HIV,” said the director of the National Institute of Allergy and Infectious Diseases (NIAID), Anthony S. Fauci, M.D., who is the trial’s co-funder. “Even a moderately effective vaccine would significantly decrease the burden of HIV disease over time in countries and populations with high rates of HIV infection, such as South Africa,” he said.

The location of the trial, South Africa, is also important, because of the aggressive strains and prevalence of HIV there. Dr. Anthony Fauci told the Guardian, “we have always said that if a vaccine is going to be ultimately effective, it is going to have to prove itself in a relatively high-risk group. So we always had the intention of extending and extrapolating the principle of the [older] RV144 study to a setting such as southern Africa.”

The current target is to bring RV144’s success rate up to 50-60 percent. “Obviously we’d like it to be 90 percent, but that is probably asking too much, given the complexity of HIV and the body’s immune response to it,” he added.

The new vaccine has been engineered to target the C clade – the southern-African strain of the virus. Those taking part in the trial will receive five vaccine shots and three booster shots, as well as additional therapy. The doctors will look at reducing the number of injections if the trials are successful.

Although treatment has reduced the number of AIDS fatalities, the disease still kills one million people per year, while two million people are infected, according to UNAIDS numbers. 

If the trial is successful, the funders will receive a license to produce the vaccine.

“We are constantly aware of the desperate need and very excited that we are finally getting on and trying something again now,” Professor Linda-Gail Bekker of the University of Cape Town, who is president of the International AIDS Society, told the British paper. “We’ve never treated our way out of an epidemic. There’s no doubt we have to have primary prevention alongside treatment in order to get HIV control, but we are not going to get HIV eradication without a vaccine. That is very clear,” she said.

The trials and vaccines are both part of a larger HIV research initiative spearheaded by Pox-Protein Public-Private Partnership, or P5 – a group of influential private and government funders, among them Bill Gates and his wife, with their Bill & Melinda Gates Foundation.