Trial of vaccine for HIV called off in South Africa

US health authorities halt a trial in South Africa of an HIV vaccine after it proved ineffective at preventing the infection.

Pharmacist Mary Chindanyika looks at documents on a fridge containing a trial vaccine against HIV on the outskirts of Cape Town, South Africa. (AP Photo/Schalk van Zuydam, File)

US health authorities have halted a trial in South Africa of an HIV vaccine after it proved ineffective at preventing the infection.

The study, named HVTN 702, began in 2016 and involved the only vaccine candidate ever shown to provide some protection against the virus that causes AIDS, in an earlier trial in Thailand in 2009.

“An HIV vaccine is essential to end the global pandemic, and we hoped this vaccine candidate would work,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which sponsored the work. “Regrettably, it does not.”

The trial enrolled about 5400 HIV-negative volunteers at 14 sites across South Africa, consisting of sexually active men and women aged 18 to 35 years old. They were randomly ­assigned to receive either the vaccine or placebo injections, receiving six doses over 18 months.

Researchers examined the data from both groups after the participants had been involved in the study for more than 18 months — the minimum time required for the vaccine to stimulate an immune response. It found that 129 HIV infections occurred among the vaccine ­recipients, and 123 HIV infections occurred among the placebo recipients, and the trial was therefore called off.

Several other trials are underway. One is being carried out in sub-Saharan Africa and South Africa; another involves sites in North America, South America and Europe. Another cutting-edge trial is investigating whether neutralising antibodies can be effective in preventing infection.

AFP