A new vaccine against HIV has been rolled out for testing in South Africa in what scientists say is the first large study of an HIV vaccine’s effectiveness since 2009.
The study will involve about 5,400 sexually active young men and women in the country.
The study is being conducted in South Africa because of its high population of people living with HIV: about seven million people in the country carry the virus.
Since the HIV virus was identified in 1983, efforts to develop an effective vaccine have proved futile.
Experts however now hope that the vaccine will help in eradicating the virus.
The vaccine regime being tested is based on one used in a trial in Thailand in 2009, which had a protection rate of about 30%. Results from South Africa are expected in four years.
According to the United Nations, more than 30 million people have died from Aids since the 1980s.
Recent breakthroughs in anti-retroviral treatments have improved the lifespan of Aids patients.
However, the only effective prevention remains abstinence or the use of barrier methods such as condoms during sexual intercourse.