Via BBC News, a long, discouraging report: The parents refusing to vaccinate their children against polio. Excerpt:
There have been more than 200 cases of polio in Pakistan since January - the first time infections have reached this level in nearly 15 years. Despite this, not everyone wants their children to be vaccinated.
Abrar Khan, who is 26, makes his way into a poor neighbourhood of Karachi called Baldia.
On his crutches, he carefully avoids potholes and dirty cesspools in the narrow alleyways lined, on both sides, with small houses.
He contracted polio when he was three. Now he's part of a team trying to change the minds of families who refuse to have their children vaccinated.
Many people here think the polio vaccination campaign is a western conspiracy to sterilise their children - it's an idea the Taliban have been putting about for 10 years now.
In 2012 the militants ordered a complete ban on vaccinations in the tribal areas in western Pakistan as a response to US drone attacks.
Since then there's been no immunisation in that area.
As a result, says the children's charity Unicef, nearly 300,000 children have missed out on vaccination in that area in the last two years.
Most of the residents of Baldia came originally from Pakistan's tribal areas and most are reluctant to immunise their children.
Yet this is considered a high risk area for polio and I can see why. There's no sanitation to speak of.
As I walk through the narrow streets, I pass an open sewer running through a residential area.
Even before you see this canal full of sewage and rotten rubbish, you can smell it.
It's just the sort of environment in which polio thrives yet around us are about a dozen children, who all look under the age of five, playing in these squalid conditions.
Khan and the other health workers are being escorted by armed policemen. Without their protection the polio team can't do their job.