It has been 16 years since a brave but fragile 11-year-old boy forced a president to flee the opening session of the 2000 International Aids Conference in Durban because he could not stand to hear the truth about HIV and Aids from the mouth of a babe. That boy was Nkosi Johnson and the president was Thabo Mbeki, who sparked international condemnation when he failed in his opening speech to acknowledge HIV as the cause of Aids.Then, South Africa's Aids response was characterised by the pseudoscience of beetroot, African potato and lemon remedies.It was Aids denialism coupled with a lack of both political will and vocal activism for access to antiretroviral drugs to treat and prevent mother-to-child HIV transmission.We were a pariah internationally - a country with one of the highest HIV infection rates in the world, but with a president and health minister who had to be forced through legal challenges to provide anti-Aids drugs to pregnant women to prevent babies being born with HIV.Thankfully, much has changed.Today South Africa has a model Aids response backed by a strong demonstration of political will and leadership. Collectively, we fund 85% of the national Aids response through public and private-sector funds. Now, around half of the country's seven million people living with HIV are on ARVs - the biggest such programme in the world.Expanded access to the drugs has seen life expectancy at birth jump from 53.4 years in 2004 to 62.5 in 2015. Mother-to-child transmission has fallen from a high of 30% in the early 2000s to just 1.5%.Health Minister Aaron Motsoaledi wants an HIV-free generation in 14 years. But challenges remain: the rate of new infections remains high, especially among young women, and the ARV programme is placing immense pressure on the stretched public-health system.But we should not be daunted. We have come so far already. Nkosi did not die in vain...