Since President Bush helped launch a massive smallpox preparedness program in 2002, local health officials say they have come a long way in developing plans to vaccinate the region's entire population in the event of an outbreak.

But three years after the Sept. 11 attacks and subsequent anthrax scare, medical experts are still struggling with how best to handle a widespread bioterrorism attack. Officials remain concerned about security, shortages of trained staff and the challenge of calming a populace likely to be terrified.

"We are better prepared, but are we prepared well enough? To an extent, that depends on the nature of the smallpox outbreak," said Daniel Lucey, director of the Center for Biologic Counterterrorism and Emerging Diseases at Washington Hospital Center.

A worst-case scenario, such as an airborne release of the virus, would be "an extremely difficult public health crisis," he said, and "an extreme challenge, to say the least."

Perhaps the greatest hurdle continues to be a lack of health care workers and first responders willing to become vaccinated. Nationwide, only about 40,000 of them have received the vaccine, way short of the initial target of 500,000, according to the Centers for Disease Control and Prevention.

In a January report derided by Republicans as unfairly partisan, Democratic members of the House Select Committee on Homeland Security concluded that the "civilian vaccination program is stalled and in disarray, threatening the security of millions of Americans."

In the District, only about 100 health professionals have received the vaccine. About 750 have gotten it in Maryland and slightly more than 900 in Virginia.

Officials said people are reluctant to volunteer to be vaccinated because of risks associated with the vaccine, which has been linked to several cases of a potentially fatal heart inflammation. And the risk of an actual outbreak has been seen as increasingly remote, health officials said, further limiting volunteers.

"There was really very little interest on the part of first-responder groups to receive the vaccine," said Lisa Kaplowitz, the Virginia Department of Health's deputy commissioner for emergency preparedness and response. "It wasn't zero, but really very little interest."

Volunteers have been so scarce that the state had to dispose of about 1,700 doses that expired after going unused, said Trina Lee, a department spokeswoman. Even so, the state still has more than 5,000 doses on hand, she said, and could request more from the CDC.

The lack of response from the medical community most likely means that vaccination of the general public would be delayed in the event of an outbreak. Those health officials and emergency workers who previously declined probably would be vaccinated first, costing precious time if panic began to set in, said Julie Casani, director of public health preparedness and response for the Maryland Department of Health and Mental Hygiene.

"We may choose to say it's important to vaccinate police and fire and EMS [emergency medical services] first," she said. "So if we have to say to a parent of four, 'You are going to have to come back tomorrow,' that's going to be hard for them to believe we are doing the right thing."

Casani and other health officials said the region has made significant strides. Counting the number of people who have received the vaccine is not the only way to measure preparedness, they said.

"We feel comfortable that all of the states have the ability to respond as quickly as possible in the event of outbreak or an emergency," said Linda Neff, director of the Office of Preparedness and Emergency Response in the CDC's National Immunization Program. "We are much better prepared than we were two years ago and much better than one year ago."

In the Washington region, interagency communication has improved, awareness of the potential for a bioterrorism attack has increased, and hospitals have built a growing number of "isolation rooms" to treat patients with highly contagious diseases, officials said. By preparing for a smallpox outbreak, they said, the region also has become more adept at responding to other medical crises, such as anthrax, SARS (severe acute respiratory syndrome) and pandemic influenza.

"Everybody is taking this more seriously," Casani said. "And if you look at a lot of the things we have in place now, they are better because we went through this exercise of smallpox planning."

The region's hospitals would not be able to handle the worst case, a situation in which everyone in the region had to be vaccinated. Because of this, officials have identified other buildings, such as schools and community centers, that could be transformed into vaccination clinics.

In the District, for example, those sites would be staffed by D.C. Health Department personnel and about 350 volunteer physicians and nurses who have been trained to help vaccinate residents. Officials would also take to the airwaves, and even go door-to-door, telling residents where to go.

Meanwhile, the CDC, which manages the national stockpile of smallpox vaccine -- supposedly enough to vaccinate every U.S. citizen -- would begin distributing thousands of doses to local health departments.

The CDC also recently launched a "Cities Readiness Initiative" in selected metropolitan areas, including the Washington region. Armed with nearly $1 million in grant money, area health officials are devising ways to distribute medicines and supplies in the event of a bioterrorism attack, a nuclear accident or a widespread medical emergency.

Less populous areas, such as Carroll County, Md., also have been preparing. In April, the county's Health Department staged a vaccination drill, using a high school as a clinic. For the most part, the exercise went smoothly. Volunteers acted as if they were sick with smallpox while health care workers practiced setting up the clinic, processing residents and delivering a mock vaccine.

Then, one of the volunteers gave them a scare. He pretended to pull out a gun, took one of the nurses hostage and demanded that he be vaccinated ahead of the others in line.

Sheriffs deputies on hand for the drill played along and diffused the situation, said Debbie Saylor, the emergency response coordinator for the county Health Department. But she said the staff learned a lesson: They may have to deal not only with a dangerous virus but with a terrified population as well.

"I think it's something that we need to expect," Saylor said.

Daniel Lucey of Washington Hospital Center said that whether the region is sufficiently prepared "depends on the nature of the smallpox outbreak."