In interviews, health officials from New York to Seattle said much of the $940 million Congress allocated to the Department of Health and Human Services in May for bioterrorism preparedness had been spent for steps to respond to the anthrax threats of 2001.

Without extra money, they said, they will have to divert time and staff members from traditional programs to smallpox.

"We understand the need to be prepared, but the load for doing this is falling principally on local health departments, and we're not getting additional funding," said Dr. Lloyd Novick, president of the New York State Association of County Health Officials.

"We have to transfer staff from other functions to do this. It just cannot be absorbed as business as usual. We need more resources."

But the likelihood of getting extra federal money is unclear.

In Colorado, Jane Anne Hollandsworth, an official of the Pueblo City and County Health Department, said her agency would continue tuberculosis clinics but might temporarily curtail standard immunization clinics for children.

State health officials said they were unaware of any planned cutbacks in state services.

There is great uncertainty about how much money will be available for federal health programs in the fiscal year that began three months ago.

The Department of Health and Human Services, like much of the federal government, is operating under a stopgap spending bill that expires Saturday.

Aides said Congress might eventually provide money to help local officials cover some of the new costs, but it appears unlikely that lawmakers will take any swift action.

The Bush administration has requested that health departments administer smallpox vaccine to health-care workers on a voluntary basis. Local health departments are responsible for giving smallpox vaccinations in two stages.

In the first, which is expected to begin this month and last about 60 days, up to 500,000 civilian health- care and emergency workers will be vaccinated. In the second, up to 10 million health-care workers, police officers, firefighters and emergency medical technicians will be offered the vaccine.

But Patrick Libbey, director of the National Association of County and City Health Officials, said many local health departments are already expecting to have trouble carrying out the first phase.

"And that is only the first step," Libbey added. "There are no plans in place yet for phase two. We don't know what kind of costs or impact phase two will have."

The Centers for Disease Control and Prevention, the federal agency responsible for tracking infectious diseases, said the vaccination program will drain resources at some local health departments.

"This is the price of preparedness," said Dr. Ed Thompson, who recently became the agency's deputy director for public health programs and services after serving as Mississippi's health director.

"It's going to cause some delays and slow the progress of other public health programs, but it's something we're just going to have to realize - that there's going to be sacrifices."

Thompson said his agency hopes to ease the problem by providing guidelines on clinic management and, in some areas, extra personnel.

In recent years, many expert panels have warned that budget cuts were causing the nation's public health system to crumble.

On top of traditional services for mothers and children, health departments have had to apply more sophisticated laboratory techniques and newer methods to counter the resurgence of tuberculosis and to keep other infectious diseases in check.

The latest demands involve a vaccine that few practicing doctors have ever given because the United States abandoned it as a routine measure in 1972, eight years before smallpox was eradicated from the world.