Updated

The Pentagon has completed its plan for vaccinating U.S. troops against smallpox, and is awaiting White House approval before giving the first shots, a senior defense official said Wednesday.

With the looming possibility of war in Iraq, the Pentagon is pushing to provide every available form of protection for troops who might be exposed to germ weapons. U.S. officials said this week that they believe Iraq is among four nations that have unauthorized samples of smallpox; tlation plan, according to the defense official who discussed it on condition of anonymity. Rumsfeld and other members of President Bush's national security team were to discuss it at a White House meeting Thursday, the official said.

The Department of Health and Human Services has set aside about 1 million doses of smallpox vaccine for the military. Those doses are expected to be provided from the 1.7 million that have been licensed by the Food and Drug Administration.

The federal government has tens of millions more doses on hand, but they have not yet been licensed and would have to be administered as an experimental drug.

Hundreds of thousands of U.S. troops have received vaccines to protect them against anthrax, and after a long pause in that inoculation program, the pace of vaccinations was accelerated in September, officials said. It is believed that Iraq has substantial amounts of anthrax that it could use against invading U.S. troops.

Smallpox vaccinations for troops could begin as early as this month, officials said, depending on the pace of coordination with the White House and other government agencies. There have been no early indications of whether some troops would object to the inoculations; hundreds have resisted anthrax vaccinations.

First to receive the smallpox vaccine would be those the Pentagon calls "first responders" — troops responsible for assisting in domestic disasters, such as a bioweapons attack. They include medical specialists. Next to get it probably would be troops in combat units designated to deploy first in a major military crisis abroad, such as an invasion of Iraq.

As many as 500,000 troops might eventually be inoculated, according to another senior defense official. Of the 1.4 million men and women in the active-duty military, fewer than half have ever received the smallpox vaccine, the official said.

For the civilian population, top federal health officials have recommended making the vaccine available in stages, beginning with people who work in hospital emergency rooms; then other health care workers and emergency responders; and finally the general public.

The White House is still considering how quickly to move — specifically, whether to wait until the vaccine is licensed or to offer it more quickly.

Smallpox was declared eradicated from earth in 1980, and routine vaccinations in the United States ended in 1972. All stocks of the virus, except those stored at official labs in Atlanta and Moscow, were supposed to have been destroyed.

It is a powerful weapon: It kills 30 percent of its victims, is highly contagious and has no known treatment.

But while the disease is frightening, so is the vaccine. It's made with a live virus called vaccinia that can cause serious damage to people vaccinated and those with whom they come into close contact. Health officials estimate that about 15 out of every million people being vaccinated will face life-threatening side effects, and one or two of those 15 will die.

The most common serious reaction comes when vaccinia escapes from the inoculation site, often because people touch the site and then touch their eyes or mouth or someone else. For instance, the virus transferred to the eye can cause blindness.

More deadly is encephalitis, which can cause paralysis or permanent neurologic damage. Also fatal: progressive vaccinia, where the virus spreads, eating away at flesh, bone and gut.