Indeed, refusal to vaccinate accounts for 2 of the children who are missed.

Yet there are things the Saudis can do to vaccinate themselves, and Yemen, from fanaticism.

These people, these 20 million people, vaccinate over 500 million children every single year, multiple times at the peak of our operation.

You could vaccinate everybody in India, but one year later there'll be 21 million new babies, which was then the population of Canada.

Last week, despite earlier breaches of the ceasefire, all parties declared that they would respect days of tranquillity to vaccinate all children in the

And they also have to dodge bullets, because we have got to operate during shaky cease fires and truces to try and vaccinate children, even in areas affected by conflict.

There have also been cases of refusal by parents to vaccinate their children, typically at the behest of clergy members, owing to the belief that such public health efforts are in fact a covert sterilization program.

I'd spoken in Somalia, Burundi, Gaza, the West Bank, India, Sri Lanka, Congo, wherever it was, and they'd all tell me, If you can create a window of opportunity, we can move aid, we can vaccinate children.

It is also why so many people are duped by exceedingly costly sugar pills sold to them by homeopathic doctors, and why we follow the advice of celebrities (rather than real doctors) about whether to vaccinate our kids.

Yet there are things the Saudis can do to vaccinate themselves, and Yemen, from fanaticism. The tentative moves toward liberalization that King Abdullah has made over the past two years need to be accelerated, made more daring, and become more effective in removing the Wahhabi ideology as an incubator for radicalism.