A young woman curled up under a yellow blanket in a Cape Town hospital ward is calm as a drip pumps fluid into her body.
This 22-year-old and 1,499 other women might emerge as heroes who used their bodies to help protect the lives of millions around the world.
She is a volunteer in an international trial to test a revolutionary way to prevent HIV infection. The AMP (antibody mediated protection) study will test whether antibodies provide protection against HIV.
The antibodies - manufactured from people who have potent natural resistance to HIV - are expected to immediately boost the woman's immune system and reduce her risk of infection.
Dr Catherine Orrell, the AMP principal investigator at Groote Schuur Hospital, said: "Instead of asking the body to make antibodies, we are giving them antibodies. We do our best to prevent HIV through education, treating STIs [sexually-transmitted infections] and encouraging women to use condoms, but some women are exposed to risk despite all that. That's when we hope the antibodies will step in."
Women like 24-year-old Sihle Koba, the first volunteer to get an infusion in this ward, are flocking to join the study which is recruiting HIV-negative women aged 18 to 40. Koba received her first infusion in July 2016.
She said: "I'm excited and want to make a change in the world. Too many people in my family have got infections."The volunteers come to the clinical trial ward every eight weeks to get the antibody infusions, and every alternate month for check-ups. None has had negative side effects so far.
Orrell said giving healthy people an IV drip was not practical for mass prevention. Down the line a product could be developed allowing people to give themselves a shot under the skin a few times a year.
Professor Lynn Morris, head of HIV virology at the National Institute for Communicable Diseases, presented an overview of the AMP study at the conference of the South African Immunology Society in Gordon's Bay last week.
The lab Morris runs is testing blood from the AMP volunteers who become infected during the trial to see if their viruses are naturally resistant to the antibodies.Like the volunteers and doctors involved, no scientists in the lab know which bloods come from the women who receive a low dose of the antibody, a higher dose, or an infusion of placebo.
This VRC01 antibody is a first-generation product and provides protection against most types of virus, but even more potent and longer-lasting ones have since been found. An antibody called CAP256-VRC26, discovered in the blood of a South African woman, is roughly 100 times more powerful than VRC01. It is being manufactured in the US for volunteers in South Africa once it has passed initial safety and efficacy trials.
"The antibody is being made in big, steel vats and it looks like a brewery," said Morris, adding that therapeutic antibodies were a major growth industry.
Previously, antibodies were used mostly for cancer treatment but now they are being made against viruses like rabies, Ebola and flu - and could in future become a powerful weapon against HIV...