If ever there was a single moment of lost innocence in global medicine, it came with the triumph of disease over the best efforts of rich nations to transfer their knowledge and expertise to the rest of the world. Yet – as veterans of the campaign to eradicate smallpox will remember at commemorative events next spring – 30 years ago they believed that soon other major infectious diseases would be similarly defeated. Instead they persist to devastating effect, particularly in sub-Saharan Africa, where malaria remains the biggest killer of children under five and where polio, although much reduced, is back on the march even in countries like southern Sudan where it once was under control, while TB kills more than HIV/Aids. And the bigger the challenge, the hotter the politics.What is often forgotten is that the victory over smallpox between 1967 and the declaration of its eradication in 1980 was, like Waterloo, a close-run thing. The very idea of a global campaign was contentious, and donor countries were slow to fulfil their promises of cash. Its success – on the back of the development of a highly effective vaccine – was due less to generous funding than to a series of other factors: smallpox’s disfiguring blisters, carried by everyone who contracted the disease, made it easy to recognise and isolate; the simple technology required for immunisation (including a fork-like needle manufactured by a sewing machine company) made it possible to vaccinate contacts quickly and cheaply, while the disease’s high death rate meant health workers were eagerly welcomed. Polio, malaria, TB and HIV all pose more complex questions than smallpox – questions that have to be answered against a backdrop of disillusionment with the efficacy of aid.Academic observers of the progress against these killers fear that the cash that comes from the UN’s Global Fund, and from other organisations such as the Gates Foundation, although producing dramatic results in specific areas – nearly 5 million lives saved, the Global Fund claimed last month – do so at the expense of scarce resources in the local community, absorbing medical effort that is desperately needed for other killers such as childbirth or diarrhoea. Better, they say, to strengthen health infrastructure and ensure local buy-in to programmes through enabling choice. Rubbish, retort NGOs such as Christian Aid, pointing to the disastrous 1990s, when the World Bank adopted that strategy. These days most effort is channelled through local organisations and is as likely to support Aids orphans at school as it is antiretroviral drugs. Where they might agree, though, is that eradication is yesterday’s ambition.