Posted: January 24, 2003 at 1:25 p.m.

SACRAMENTO (AP) -- California's largest nursing union is discouraging its members from participating in the nation's voluntary smallpox vaccination programs.

The California Nurses Association, which represents 50,000 registered nurses, joined a growing number of critics Thursday. The national plan calls for the inoculation of a half-million medical personnel as a precaution against a bioterrorist attack.

However, the nurses union wants the state to delay the plan amid worries there aren't enough safeguards in place to ensure people at high risk of injury aren't vaccinated.

Health officials have said the smallpox inoculation is the most dangerous vaccine available, historically killing one to two people per 1 million vaccinated. It can cause serious side effects, including runaway infection and brain inflammation.

The nurses union also worries that someone who has just received the vaccine could be contagious.

"In terms of being a patient advocate, that's a concern," said union spokeswoman Lisebeth Jacobs. "Anyone who's provided health care knows that patient care can involve very physical, intimate contact with people. These are immunocompromised people in the hospital."

Jacobs said the union opposes the plan for political reasons.

"We feel that this program is fanning the flames of fear among the public and contributing to efforts to generate support for what we feel is an ill-conceived war (against Iraq)," she said.