This year, UNAIDS Executive Director who is in South Africa for the event stressed the need for people to know their statuses in his message.
World AIDS Day takes place on the 1st December each year and has been celebrated since 1988.
Lloyd Russell-Moyle, from the opposition Labour Party, said he wanted to "say to those living with HIV that your status does not define you".
Deputy President and chairperson of the South African National AIDS Council, David Mabuza, has encouraged South Africans to get tested for HIV. In the video, he said: "To show our support for the children of Lesotho [where Sentebale works] and help reduce the stigma for all those affected by HIV, we are turning this World AIDS Day into a day in which no one should feel any shame about their secrets". In 2017, 9.4 million people were simply unaware that they are living with a potentially deadly, but treatable, disease.