Polio could be eradicated in Pakistan within months, health officials say, as a mass vaccination drive is launched.
A World Health Organisation spokesman told the BBC only a handful of cases have been reported this year in Pakistan and neighbouring Afghanistan.
The two countries are the last places where polio remains endemic.
It is hoped millions of children will be vaccinated over three days. Police escorts will guard against Islamist militants who oppose immunisations.
“The challenges we have are both logistics and security,” the WHO’s representative for Pakistan, Dr Michel Thieren, told the BBC.
He said about 70,000 medical staff aimed to immunise almost 10 million children in the drive, which is taking place in Khyber Pakhtunkhwa and semi-autonomous tribal areas in the north-west, as well as in south-west Balochistan province.