WASHINGTON (CNN) -- Eight members of the military who objected to getting a mandatory anthrax vaccination lost another round in federal court Friday.
Marine Corps Lance Cpl. David Stuart gets an anthrax vaccination last week at Camp Lejune, North Carolina.
A District of Columbia federal judge dismissed a lawsuit from service members who claim the federal government is forcing them to take an unproven and potentially ineffective drug to stop the deadly bacteria.
The ruling was the latest in a long-running legal fight over the vaccine.
In 2001 -- shortly after the September 11 terrorist attacks -- anthrax poisoning killed five people in the United States.
The material was sent through the mail, along with threats, to various media outlets and government officials, including members of Congress and the Supreme Court. No arrests have been made.
Several other scares have occurred since then, and anthrax was reported as one of the weapons of mass destruction that Iraq was alleged to be hiding before the 2003 U.S.-led invasion.
The military, concerned that anthrax or other biological agents could be used against troops by terrorists or insurgents in global conflicts, began a mandatory inoculation program in 1998.
The eight plaintiffs, fearing side effects, wanted to make the vaccine optional.
The Pentagon program was suspended four years ago after a federal court found the Food and Drug Administration's approval process to be improper.
The mandatory inoculations resumed after revised protocols found the vaccine to be safe.
On Friday, U.S. District Judge Rosemary Collyer ruled the FDA's revised approval process was appropriate.
"The FDA applied its expertise and found the vaccine is effective," Collyer wrote. "The FDA did not act arbitrarily or capriciously. ... The court will not substitute its own judgment when the FDA made no clear error in judgment."
The vaccine -- marketed by the trade name BioTrax -- is licensed to be given in a six-dose regimen over nearly 20 months.
"Force protection is the No. 1 priority for the Defense Department," Pentagon spokesman Bryan Whitman said in reaction to the judge's ruling.
"The safety and efficacy of the vaccine has been well documented and this nation owes its service members that are going into harm's way the best possible protection this country can afford them to be able to operate in any number of environments."
Anthrax, one of the most dangerous biological agents, is a bacterial disease whose spores can cause infection through inhalation, ingestion or skin contact.
Antibiotics are used when symptoms are detected, but inhalation anthrax has an estimated fatality rate of 45 percent to 90 percent, according to the federal Centers for Disease Control and Prevention. Collyer cited those figures in her ruling.
The eight plaintiffs were Thomas Rempfer, Joshua Cohen, Gareth Harris, Kevin Ferrara, Shameka Edwards, Eric Gearhart, Michael Palmer, and James Hailstone. There was no initial reaction from their attorney. E-mail to a friend