Gathering former heads of state, top experts on AIDS and gender health as well as Ethiopian super-model Liya Kebede, the "Champions for an HIV-free Generation" are pledging to nail HIV prevention to the political masthead.
"Thanks to the unprecedented effort of the global community, millions are now receiving life-saving AIDS treatment," Mogae told reporters at the International AIDS Conference.
"But for every two people we treat in Africa this year, five more are infected. We urgently need innovation and invigoration of HIV prevention in Africa."
Founding members of the group include Joaquim Chissano, former president of Mozambique; former Zambian president Kenneth Kaunda; South African Archbishop and Nobel peace laureate Desmond Tutu; Miriam Were, who heads the Kenyan National AIDS Control Council; and Edwin Cameron, a judge on South Africa's Supreme Court of Appeal.
Mogae, who stepped down this year, has won widespread praise for spearheading HIV testing and widening access to antiretroviral drugs in Botswana, one of the world's worst-hit countries for the human immunodeficiency virus (HIV).
Botswana lies in the epicentre of the world's HIV pandemic. Globally, 33 million people have HIV. Two-thirds of them live south of the Sahara.
But prevalence is highly concentrated in nine southern African countries -- Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe -- where rates range from 15 to 25 percent.
This sub-region accounted for 35 percent of HIV infections and 38 percent of AIDS deaths in the world. South Africa alone has 5.7 million people with the virus, the highest on the planet.
While placing the emphasis on southern Africa, Mogae said the "Champions" initiative would be open to prominent people from all over Africa and "from all walks of life."
As opinion leaders, they would seek to launch "a dialogue" with governments about changing behaviour and reforming practices that encourage the spread of HIV, such as unsafe sex, stigma and discrimination against women.
The hope would be to reach a consensus with current political leaders, "but even if it doesn't emerge, we will advocate things that we believe [in]," said Mogae.
Cameron set the 2000 International AIDS Conference in Durban ablaze with an speech detailing his own infection with HIV and his luck, as a wealthy man, in being able to buy antiretrovirals that in those days were hugely expensive.
He told Tuesday's press conference that South Africa's tragedy could be traced to the early years of this decade, when infection spread under what he called the "AIDS denialism" of South African President Thabo Mbeki.
"Stronger, more visionary and outspoken language must come from the continent most affected by this epidemic," Cameron said.
Kenya's Were said her stress was on discrimination, taboo and gender imbalance that, in many African countries, provided fertile ground for the lethal virus to spread.
"Not everyone might be comfortable with it, but we need to talk about HIV, about stigma, about our behavior, because silence and inaction are fatal," she said.
Stephen Lewis, a former UN special envoy for AIDS in Africa, praised the "Champions" initiative for its innovative bid to raise the visibility of HIV prevention.
"This will be interesting. Former presidents can wield a lot of influence," he told AFP.