Nine people working on a UN-backed polio vaccination campaign in Pakistan are reportedly dead after gunmen, thought to be from the Taliban, attacked. Tom Clarke reports.

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By the year 2000 the World Health Organisation thought they had polio licked. Cases of this crippling, sometimes fatal disease had fallen by 99 per cent.

Experts began planning for the so-called polio "endgame" - the careful but gradual withdrawl of vaccine that would leave the world polio-free once and for all.

Twelve years on, polio is still nearly licked, only they're not talking about the endgame anymore. The virus has clung on doggedly in extreme Islamist strongholds of northern Nigeria, Pakistan and Afghanistan. This week's murders make the prospect of a polio-free world seen even more remote.

Progress was being made. Two years ago a new board overseeing global eradication efforts chaired by England's former chief medical officer Sir Liam Donaldson was brought in to shake things up.

Pressure on clerics

Local pressure on extremist clerics had improved access to many areas. Using women to administer the vaccine also helped gain access to mothers and babies that had often been inaccessible to male health workers in previous campaigns. And in one of the most difficult countries, real progress had been made. Last year in Pakistan there were more than 200 cases. That fell to just 56 this year.

Yet, just as they were doing so well, Pakistan's immunisation teams were targeted. Some observers say the WHO could have been better at predicting attacks. The mood towards vaccination teams had soured following revelations earlier this year that the CIA had used a fake polio eradication team to access Osama Bin Laden's hide-out.

And though the polio eradication effort has endured setbacks before - like a ban imposed by some clerics in northern Nigeria - this week's violence is of a different stripe. These were carefully planned executions with political motivation but we don't know who is involved.

But with eradication of the disease so close globally, there is also much to lose. If the disease continues to lurk in its last three strongholds, the WHO estimate that within a decade there could be 200,000 cases worldwide each year.

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