JOHANNESBURG (AP) — Scientists say a new vaccine against HIV, to be tested in a trial to be launched in South Africa this week, could be "the final nail in the coffin" for the disease if it is successful.

Anthony Fauci, director of the U.S. government's National Institute of Allergy and Infectious Diseases (NIAID), said Sunday, in a statement released ahead of the trial, said the new vaccine is promising.

The study, called HVTN 702, is to begin Wednesday and aims to enroll 5,400 sexually active men and women aged between 18 and 35 at 15 sites across South Africa.

It will be the largest and most advanced HIV vaccine clinical trial to take place in South Africa, where more than 1,000 people a day are infected with HIV.