“This vaccine weakens the reproductive system of men and women,” said Haji Abdul Nadir, a 47-year-old businessman in Kandahar.

“The majority of the people think it’s a campaign from the infidels.

They’re trying to stop the Muslim generation.” Although some countries have eradicated polio, the crippling disease continues to haunt Afghanistan.

The country’s deserts, rocky mountains and landmine-studded roads make it difficult for medical aid workers to reach isolated settlements.

Distrust has also complicated the work.

Afghans have a long tradition resisting what they consider foreign interference or domination, most notably against the Soviets in the 1980s war.

Some aid workers say the suspicion of Westerners has risen because of botched U.S. military operations, including a July 1 airstrike in Uruzgan province, which have caused civilian casualties.

“We’re not armed, so often when we go to these remote villages we have to make them see that we’re from the United Nations,” said Douglas G.

Higgins, a program officer for UNICEF, which is coordinating the immunization campaign.

“Often, the only defense that we have are these,” he said, pointing to the circular UNICEF emblem on his beige vest.

As an effort to reach high-risk districts in southern Afghanistan, UNICEF coordinated a three-day “mop-up” immunization campaign, which concluded Thursday.

Workers were able to reach an estimated 85,000 children under 5.

Another campaign is set to begin in September.

“Doctors tell me it’s a good thing and I believe it,” said 25-year-old Rangeena of Kandahar, who only uses one name, as her children received two drops of the orange-colored vaccine on Thursday outside their adobe house.