The Air Force will proceed with a court-martial against one of its doctors who disobeyed an order to take the anthrax vaccine.

The Air Force made the announcement Friday afternoon at Keesler Air Force Base, where Capt. John Buck serves as an emergency room physician.

A day earlier, a military judge ruled that Buck disobeyed a lawful order when he refused to take the germ warfare vaccine last year before deployment to the Middle East.

Buck, 32, claimed in a pretrial motion that the vaccine is an experimental and potentially hazardous drug unlawfully forced on soldiers.

After four days of proceedings, Lt. Col. Mark Allred ruled Thursday against Buck's motion. He said the order was lawful.

Buck submitted his resignation minutes after Allred's ruling and had hoped the Air Force would drop the court-martial or delay it until military brass could act on the resignation.

The Air Force said it would move forward with the court-martial while Buck's resignation made its way through the Air Force chain of command.

"Since Captain Buck declined nonjudicial punishment and demanded to have a court-martial hear his case, this trial remains the fairest method of dealing with this matter," the Air Force said in a written statement. "The considerable protections available under military law ... are all reasons why continuing this trial is in the best interests of the Air Force."

The statement said resignation requests usually are made "long before the start of trial."

"In this case, however, trial has already begun," the statement said.

Buck was scheduled to appear before Allred at 2 p.m. to enter a plea. The trial was expected to resume Monday -- the same day that Buck was to be promoted to the rank of major.

During the four-day pretrial hearing, a Maine doctor testifying for Buck said the anthrax vaccine used in government programs was thoroughly tested only on animals.

The military, on the other hand, insists the vaccine is the best weapon against biological attacks. Pressure mounted to immunize soldiers to biological agents in the wake of the Gulf War.

Anthrax is a disease that typically afflicts animals, especially sheep and cattle. Dry anthrax spores, which can be put into weapons, can cause death in humans if inhaled.

Buck has become a key figure in the resistance to the mandatory anthrax program. He and a former Air Force major filed suit May 2 against the Food and Drug Administration and the Defense Department in U.S. District Court in Washington seeking to end the program.

If the class action lawsuit is successful, more than 200 soldiers discharged or disciplined for refusing to take the vaccine could have their records expunged.