The Health Department yesterday indicated that between 500 and 700 health workers are expected to be vaccinated over the next several months as part of smallpox preparation efforts tied to the possibility of the disease being used as a weapon by terrorists.

This round of vaccinations would be given to workers who would be called on to investigate suspected cases of smallpox and treat them.

Those who will be offered the vaccine will be told what conditions may indicate they are at higher risk to suffer complications. People at higher risk include pregnant women, people with skin conditions such as eczema and those with weakened immune systems.

No decision has been made to launch widespread public vaccinations such as those required by the Kingdom of Hawai'i in 1854 and again by territorial and state laws first passed in 1896.

Those catastrophic outbreaks of the 19th century led to the founding of the Board of Health, which has evolved into the state Department of Health.

Dr. Paul Effler, Health Department communicable disease division chief, said the 1853 outbreak was "one of the worst" in Hawai'i history.

As for a outbreak now, Effler said the probability of an intentional release of smallpox remains low but that the serious consequences of such a disease justify the preparation of emergency response teams.

As a physician working in this field, he said he plans to get the vaccine himself.

The state's health director, Dr. Chiyome Fukino, said 200 to 300 of the Health Department's employees initially volunteered and 300 to 400 more from hospitals have volunteered to be inoculated as part of the emergency response teams.

Smallpox is usually spread by face-to-face contact, through droplets of saliva passing from one person to another.

Some of the concern about the vaccination is its use of a related live virus — not smallpox itself — called vaccinia. Someone who receives the vaccine could spread vaccinia to family and friends.

If wider vaccination is needed, Effler said officials believe it would be possible to vaccinate the entire population in less than two weeks.

Only three local hospitals are not participating in the effort: the Hawai'i State Hospital, Castle Medical Center and Shriners Hospital for Children.

Effler said the Health Department is discussing the voluntary effort with the union that represents some of the targeted workers. Randy Perreira, Hawai'i Government Employees Association deputy executive director, said: "They assured us that it's purely voluntary. They are taking as many precautions as they can."

Perreira said extensive pre-screening should help reduce the number of people who may be at risk getting the shot. He said they are still working on concerns about needle-stick injuries from the long needles traditionally used for the vaccination and "looking at the possibility of using safety needles."

Author O.A. Bushnell wrote about the devastating disease in "The Gifts of Civilization: Germs and Genocide in Hawai'i." He said official estimates of the time indicated that smallpox killed nearly 6,000 people — at a time when the population of all the Islands stood at 84,000. Other census information placed the loss of life at between 10,000 and 15,000, most of them Hawaiians with no immunity to the foreign ailment.

The limited information available about outbreaks in Hawai'i showed that native Hawaiians "were very severely affected compared to other groups that were here," Effler said.

Historian Gavan Daws painted a portrait of devastation in Honolulu caused by smallpox with teams of wagon drivers patrolling the town picking up the sick and the dead. In "Shoal of Time," Daws wrote that "wagoners became so hardened to death that they were able to stop at a tavern for a drink, leaving their load of corpses outside."

Effler said the officials of the day used some of the same tools that would be used now: "Trying to isolate people and quarantine individuals and also vaccinate people that had been exposed."

In 1974, Hawai'i became the last state in the nation to repeal mandatory vaccination for residents who were 1 year old and older.