ATLANTA, June 18 — Government officials said today that both the civilian and military smallpox vaccination programs had virtually come to a halt, the military program because it has vaccinated everyone it can and the civilian program because few people volunteered for it.

Officials also said that of the 493,000 people who had been vaccinated, the rate of dangerous side effects was lower than predicted.

"I take that as proof that our screening succeeded marvelously," said Col. John D. Grabenstein of the United States Army surgeon general's office, who was in charge of the military's inoculation.

Although eight people had heart attacks after immunizations and three died, it is unclear whether the deaths were coincidental, said officials at a conference here today on immunization policy. The conference was convened by the Centers for Disease Control and Prevention.

The heart attack victims were middle-aged, and several had clogged arteries, diabetes or other risk factors like smoking. There were no deaths from encephalitis, eczema vaccinatum, progressive vaccinia or the other side effects predicted last year based on studies from smallpox vaccination drives in the 1960's.

The military has inoculated 454,856 personnel, nearly 90 percent of them before the invasion of Iraq and is now vaccinating about 1,000 a week, which Colonel Grabenstein called "maintenance." State health departments have inoculated only 37,608 civilian emergency health workers and are adding about 100 more each week.

President Bush announced last December that the country would vaccinate up to 500,000 civilian health workers as a first line of defense against a terrorist smallpox attack. White House officials said there was evidence that President Saddam Hussein of Iraq either planned to use smallpox as a weapon or could have given it to terrorists.

But the program got off to a slow start and Dr. Raymond A. Strikas, director of smallpox preparedness in the centers' immunization division, said volunteers dropped off sharply after late March.

Dr. Strikas cited several reasons:

¶With a quick victory in Iraq, Americans felt the threat had faded.

¶The heart attacks and cases of inflamed heart muscle led the centers to ban immunization for anyone with heart disease on March 25.

¶Nurses and others resisted immunization until a law to compensate them if they were hurt was passed; it was not signed until April 30.

¶SARS and monkeypox competed for state health resources and public attention.

"What we are in now is what we call the natural pause between Stage 1 and Stage 2," Dr. Strikas said, with Stage 2 being the 500,000 goal.

Phase 3 would have extended vaccination to the general public, he said, "but there's been relatively little clamoring for that."

Asked if the centers were disappointed that so few had volunteered, he said: "We accept where we are, given the circumstances. We can make this work."

The smallpox vaccine, Vaccinia, is the most dangerous vaccine, and health experts predicted it would cause serious adverse reactions in one in 19,000 to one in 71,000 people and would kill one or two in a million. But they predicted brain inflammations or the uncontrolled spread of vaccinia pox, not heart attacks.

The government ordered large supplies of vaccinia immune globulin, an antidote for bad reactions. It was needed only three times, instead of the roughly 50 times that the 1960's studies would have predicted.

About 125 women who were pregnant or became pregnant were inadvertently vaccinated, despite screening, Colonel Grabenstein said. Thus far, there has been no vaccinia in fetuses, and miscarriage rates have been normal, though they are still being followed.

In the past, there were reports of myocarditis and pericarditis inflammation of the heart and the sac surrounding it from Australia and Finland, but they used more virulent vaccinia strains, doctors said.

Heart inflammations were not identified in the 1963 and 1968 American studies that experts consulted last year when planning the immunization drive, said Dr. Juliette Morgan of the National Immunization Program at the centers.

Vaccination did seem to increase the risk of myocarditis in the military vaccines, Dr. Morgan and Colonel Grabenstein said. Of the 18 cases that have been most studied among 53 possible ones, all were young healthy men who developed chest pains and abnormal enzyme levels; all seem to have recovered. That was 3.6 times the number that might have been expected to develop myocarditis anyway.