Around 240,000 children in northwest Pakistan at risk if an inoculation campaign cannot start next week due to Taliban's polio vaccination ban, warn officials.
Local Taliban and Pakistani warlord Hafiz Gul Bahadur, whose followers are fighting Western troops in Afghanistan, have banned polio vaccinations in the northwestern tribal region of Waziristan to protest against US drone attacks.
They have condemned the immunization campaign, which is slated to begin on Monday, as a cover for espionage.
"There is possibility that we may have to skip the polio campaign in North and South Waziristan because we are not getting clearance from the army nor is the situation conducive," a government health official told AFP.
"We have threats from the Taliban. Going to these areas for a polio campaign would be tantamount to putting the lives of our staff in jeopardy," added the official, speaking on condition of anonymity.
Pakistani doctor Shakeel Afridi was jailed for 33 years in May after helping the CIA find Osama bin Laden using a hepatitis vaccination program as cover.
Fawad Khan, director of health services in the tribal belt, told AFP that at least 160,000 children in North Waziristan and 80,000 in South Waziristan would be affected if polio drops are not administered.
Talks are ongoing between administrators and the Taliban, but health workers had "not yet received the green light" for going ahead in Waziristan, he added.
But a senior security official said tribal elders would on Monday discuss how to launch the campaign.
In South Waziristan, where the army fought local Taliban in 2009, the official said "it should not be difficult" to vaccinate children "at least in areas where displaced persons have returned".
The Lancet medical journal has said vaccination problems led last year to Pakistan's highest number of polio cases in a decade, 198, compared to 144 in 2010.
Polio remains endemic only in Afghanistan, Pakistan and Nigeria.
The highly infectious disease affects mainly the under-fives and can cause paralysis in a matter of hours. Some cases can be fatal.