ISLAMABAD: Pakistan has witnessed a sharp drop in the number of families refusing to get their children vaccinated against polio, officials said Monday, while lamenting that nearly half a million children were left unvaccinated.

“The number of refusing families has declined (44 per cent) from 80,330 during the first national polio round held in January to 45,122 in October,” the World Health Organization, the UN and the government said in a joint statement.

Around 32 million children were targeted during the three-day nationwide drive last week, backed by the government and WHO.

Prayer leaders from mosques' loudspeakers have been telling parents not to give polio vaccine to their children, dubbing the campaign a Western “conspiracy” to reduce the population of Muslims.

Earlier this year, a Pakistani doctor was jailed for helping the CIA track down al Qaeda chief Osama bin Laden in 2011 using a fake hepatitis vaccination programme, leading the Taliban to ban immunisation in some areas.

“The success achieved notwithstanding, every unvaccinated child constitutes a major challenge,” said Elias Durry, a senior coordinator for polio eradication at WHO.

“It is a cause of grave concern that polio teams across the country have still missed 484,344 children during the last polio round,” Durry said.

He expressed concern over polio teams “persistently missing the same children that have remained unvaccinated for the last many campaigns”.

Shahnaz Wazir Ali, a senior adviser to the prime minister, called for reaching out to the children who could not be given polio vaccine drops during the latest campaign.

“We need to take adequate steps to ensure that the number of children missed for reasons other than refusals is also brought down,” she said.

Pakistan is one of only three countries where the highly infectious crippling disease remains endemic, along with Afghanistan and Nigeria.

There have been 30 confirmed cases of polio in Pakistan this year according to the government, 22 of them in the tribal areas bordering Afghanistan.