(CNN) -- A ban on polio vaccinations imposed by the Taliban could affect about 280,000 children living in tribal areas of northwest Pakistan, according to estimates from the World Health Organization.
Last month, local Taliban militants prohibited polio vaccines over the United States' use of drone strikes in the region.
When a three-day nationwide effort to administer polio vaccines began this week,health workers and volunteers weren't able to immunize children in North and South Waziristan.
Under this security situation, they "obviously cannot operate," said Mazhar Nisar, the health education adviser in the Pakistani prime minister's polio program. "We're hoping that the campaign will resume in the near future."
Throughout the rest of the country, vaccination efforts continued as 180,000 health workers and volunteers fanned throughout communities trying to immunize 34 million children, under the age of 5.
The vaccine ban began in June after a Taliban commander in northwest Pakistan declared in a statement that the vaccines "would be banned in North Waziristan until the drones strikes are stopped."
The commander, Hafiz Gul Bahadur said that the drone strikes "are worse than polio," and consulted with other Taliban leaders regarding the decision, according to the statement. Drone strikes are widely unpopular, as the Pakistani government has pressed the U.S. administration to stop the attacks. 20 dead in drone attack in Pakistan
Pakistan remains one of the three countries in the world grappling with polio. The country has had 22 reported cases this year. The other two countries are Afghanistan with 11 cases and Nigeria with 54.
Polio is highly contagious and can cause paralysis, breathing problems, deformities and death. There is no cure for polio, so the focus lies on vaccines to prevent the disease.
The vaccine is administered orally, and in multiple doses to achieve full immunity.
Pakistan's tribal regions are areas where polio is known to be active, according to disease data.
"In a situation like this, any child who has not been administered for polio vaccine remains at risk," Nisar said.
Vaccination points have been set up in the entry and exit points to the tribal areas, he added.
The WHO, Center for Disease Control and Prevention, UNICEF and Rotary International have a joint polio eradication campaign.
"Our concern is reaching every single child possible," said Michael Coleman, a communication specialist for UNICEF and polio. "Where there are limitations presented, it's a concern."
To date, Pakistan "has had real progresses," said Coleman. "People are being reached, we need to be keeping that momentum up."
This is not the first time that Pakistan's polio campaign has made headlines.
Last year, a Pakistani doctor was linked to a CIA operation to verify Osama bin Laden's whereabouts with a door-to-door vaccination campaign in the town of Abbottabad, where the al Qaeda leader was hiding before he was killed.
U.S. officials have said the plan did not work, but aid groups and Pakistani health officials have said the CIA's alleged meddling with a vaccination campaign undermined Pakistan's efforts to eradicate polio.
The ban on the polio vaccine has drawn criticism.
"Proscribing inoculation merely because some score is to be settled with the U.S. or the government is again an act of extremist proportions that would earn the Taliban more public anger," stated an editorial from The Nation, a Pakistani newspaper.
Nisar pointed out that both Western and Islamic countries have eradicated polio through vaccines.
"There is no reason why Pakistan cannot do it," he said. "This message needs to be disseminated, it needs to be reinforced. This is a campaign which saves the children from permanent disability. There cannot be a reason to deny one's children of this facility."