A federal program to inoculate health care workers against smallpox is near a standstill, as fear of a potential terrorist attack has subsided -- and fear of the vaccine's side effects has increased.

The situation in Santa Clara County reflects what is happening nationwide. The county received 500 doses, but just 119 health care workers have been immunized since the voluntary program began in March.

``Smallpox is not a highly contagious disease, contrary to public opinion,'' said Liz Jacobs, a registered nurse and spokeswoman for the California Nurses Association. ``You have to have pretty direct contact with someone who's infected. It didn't add up to anything that made sense for the greater good of the public.''

The association, which represents 50,000 nurses across 150 hospitals statewide, had urged its members not to receive the vaccine because of its health risk. Most individuals who are immunized will experience mild reactions, such as soreness at the point of vaccination, fever or body aches. However, more serious side effects include heart attacks, chest pain or severe allergic reactions.

In March, state health officials temporarily stopped the vaccination program after three vaccinated workers died from heart attacks. The program was restarted shortly after, but participation has lagged.

Malinda Markowitz, a registered nurse at Good Samaritan Hospital in San Jose and a secretary of the union, decided not to be vaccinated. She said she was concerned about exposing patients to the vaccine, which contains a live virus called vaccinia that helps the body develop immunity to the disease. If a patient were exposed, he or she could be susceptible to the vaccine's side effects, particularly if they have a weakened immune system.

``Many of them are fragile, and I wasn't assured that there wouldn't be negative things happening to the patients,'' Markowitz said.

Laura Levin, a nurse for the Santa Clara County Health Department, volunteered for the vaccine. While she does not deal directly with patients, she would be part of first response teams to assess possible cases of smallpox.

``We are always weighing risk of potential exposure to communicable diseases,'' Levin said. ``I'm willing to accept a certain level of risk. I also believe that my risk was very, very small.''

Valentine Reyes, a registered nurse at Santa Clara Valley Medical Center, is among the two dozen health care workers at the hospital who were immunized, he said.

``We needed to be ready and prepared,'' Reyes said. ``If it ever happened, this facility would be able to function.''

Smallpox, a contagious, infectious disease distinguished by a rash of red sores, was deemed eradicated after a worldwide vaccination campaign. The last known naturally occurring case was reported in Somalia in 1977. Fears that the disease could be used in an attack grew as U.S. officials prepared for a war in Iraq.

Officials launched plans for a smallpox vaccination program geared toward military and emergency health care workers in December 2002. The Centers for Disease Control and Prevention began distributing the vaccine in January. About 37,800 health care workers have received the vaccine nationwide, including 1,847 in California.

The unused 381 doses in Santa Clara County will expire Aug. 30. Volunteers for the vaccine were screened because individuals with conditions that could weaken their immune system, such as AIDS, cancer or eczema, are at higher risk for side effects and should not receive the vaccine.

While requests for vaccinations have declined, individuals are still receiving the vaccine, said Ken August, spokesman for the California Department of Health and Human Services.

Earlier this month, the group that is overseeing the federal immunization recommended against expanding the program to include emergency-response workers, such as police, firefighters and hazardous-materials crews.

Nonetheless, several local agencies have expressed interest in allowing emergency workers to be vaccinated. August said the state will work with those agencies to help develop immunization plans.