A highly efficient vaccine would be a “game-changer”, but results of the new trials will take years, scientists say.

According to Aljazeera, South Africa has launched a major clinical trial of an experimental vaccine against the AIDS virus, which scientists hope could be the “final nail in the coffin” for the disease.

More than 30 years of efforts to develop an effective vaccine for HIV have not borne fruit, but for the first time since the virus was identified in 1983, scientists said on Wednesday they think they have found a promising candidate.

The new study, known as HVTN 702, will involve more than 5,400 sexually active men and women aged 18-35 in 15 areas around South Africa over four years.

It is one of the biggest clinical trials involving the disease ever undertaken and has revived hopes of a breakthrough in the battle against AIDS.

“If deployed alongside our current armoury of proven HIV prevention tools, a safe and effective vaccine could be the final nail in the coffin for HIV,” said Anthony Fauci, director of the US National institute for Allergies and Infectious Diseases (NIAID), which is taking part in the study.

“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.”

Condoms are at the frontline of efforts to prevent the spread of HIV, which is mainly transferred through the sexual fluids and blood of infected individuals.

A small number of people, mainly in developed countries, use virus-suppressing drugs as a preventive aid, although the exact level of protection this offers is not clear.

But relying on existing prevention methods was not working, said Mmapule Raborife, one of HIV Vaccine Trials Network’s community advisors in the large township of Soshanguve, north of the administrative capital Pretoria.