GRAND FORKS (AP) - Anthrax vaccinations are being given to Grand Forks Air Force Base airmen who are destined for overseas duty.

Lt. Col. David Nelson, medical squadron commander at the base, said airmen have not resisted the mandatory vaccinations, which began on March 19.

"There is evidence that several countries have produced anthrax as a weapon," Nelson said. "Anthrax is out there, especially in the high-risk areas of the Middle East and on the Korean Peninsula."

In December, members of the military sued to prevent the Pentagon from requiring anthrax vaccinations, the latest legal challenge over the vaccine's possible health risks. The suit was filed by six military members and defense contractors on behalf of U.S. troops worldwide.

A federal judge suspended the program in 2004 after finding fault in the Food and Drug Administration's process for approving the drug. The FDA has since reaffirmed its finding that the vaccine was safe, which cleared the way for the Department of Defense to reinstate the program.

Health officials at the Grand Forks base say the program is prudent.

"The threat is real," said Maj. Chris Wynens, base public health officer. "Anthrax used as a biological weapon is one of the most available, easily produced and … relatively cheap to manufacture bio-weapons for any terrorist organization."

Information made available before the mandate has lessened the fear about the vaccination, Wynens said, and resistance to the vaccination has been nonexistent.

"I think the fear came from the unknown," Nelson said. "Now, plenty of people have received the vaccination with no ill effects. No one has refused, and that largely reflects our educational efforts."

The vaccination is given in a series of six shots over an 18-month period. For continued protection, an annual booster is required.

Both Nelson and Wynens have received the vaccination.

"There is a bit of a burning sensation at first," Nelson said. "But other than that, it was just like being vaccinated for the flu."