Provincial health officer Dr. Perry Kendall said the measure is being implemented this season for staff at publicly funded facilities including long-term care homes because less than half of health-care workers get vaccinated.
Kendall said the flu causes more deaths every year than all other vaccine-preventable diseases combined and hospitalized patients and seniors are more at risk of complications from it than the rest of the population.
"Influenza is not a trivial illness, particularly for vulnerable people," said Kendall.
"We know that a surprising number of health care workers will go on working even when they have symptoms of influenza and there are case studies showing how vulnerable patients in hospitals do get influenza and get serious complications."
The B.C. Nurses Union said it won't formally respond to the policy immediately. Union officials will be meeting in the coming days with the Health Employers Association, a spokesman said.
However, the union pointed to a release it sent last year in response to the issue.
"Flu vaccines should be promoted through education, rather than through a punitive approach by the employer," read the sub-head on the Oct. 2011 news release, which went on to promote the vaccination.
"BCNU encourages members to get a flu shot to reduce the risk of developing serious illness."
Kendall said health authorities in B.C. have been trying to get immunization numbers to go up "for years," but said despite the encouragement, levels have decreased since 2010.
Flu season typically runs from late November or early December to the end of March, and if health-care workers do not want to take a jab, they will have to wear surgical masks anywhere in the hospital at all times, except in cafeterias.
The flu shot is provided for free in B.C. to high-risk populations including seniors, aboriginals, people with chronic health conditions and those with compromised immune systems.
The B.C. Centre for Disease Control issued a release in support of the new policy, pointing out vaccination protects the workers and their families.
"However, health care workers currently have very low coverage rates," the release said.
"Last year, only about 40 per cent of health-care workers at acute-care facilities and 57 per cent at residential care facilities got the flu vaccine."
Kendall said there are myriad reasons for workers not getting vaccinated, ranging from misconceptions about the shot to a simple matter of convenience.
He said places in the United States that have introduced mandatory immunization or mask policies have seen vaccination rates climb to more than 95 per cent.