A final push to overcome the few remaining pockets of polio infection in the world is being supported by grants totalling US$630 million from the Bill & Melinda Gates Foundation, the humanitarian group Rotary International, and the UK and German governments.

The funding, announced on 21 January, will support the World Health Organization's Global Polio Eradication Initiative, which involves vaccinating billions of children. Since its launch in 1988, the effort has cut the annual polio toll from 350,000 cases in 125 countries to just 1,600 cases last year. If the crippling disease could be eradicated, it would become the second disease, after smallpox, to be officially wiped out.

Reservoirs of polio now remain in four countries where the disease is endemic: Nigeria, where polio vaccines were opposed following false rumours that they carried HIV and caused female infertility; India, where vaccine effectiveness has been hampered by poor sanitation and high population density; and conflict zones in Afghanistan and Pakistan.