The BBC reported that rumors spread by local clerics via FM radio allege that the vaccines are an "American conspiracy" to reduce the population of Pakistan.
Immunization teams have been beaten up in some areas, and some parents refuse to allow their children to be immunized, the BBC said.
Last year, a lab tested samples of the vaccine after allegations were made in the Peshawar High Court that the vaccine contained the hormone estrogen. Health official Waheed Khan said the vaccine did not contain any estrogen, the BBC said.
The World Health Organization has undertaken a $196 million annual campaign to control polio in Pakistan. According to WHO, polio viruses that originated in Pakistan, Afghanistan, India and Nigeria spread to 1,902 people worldwide last year.