EVERETT — The union that represents The Boeing Company’s machinists began negotiations Friday, after the company announced it would terminate workers who don’t comply with a new vaccine mandate.

“We are not against vaccinations and believe the vaccine is good for public health and safety,” wrote the IAM District 751 union in a letter to its members. “However, we must advocate for all our members; those that will not become vaccinated along with members who will get vaccinated. No matter a member’s opinion on this issue, we must stand and protect our members’ jobs as best we can. We are looking at all options as we move through effects bargaining.”

More than 100 people protested the mandate Friday, near the IAM District 751 union hall. People lined both sides of Airport Road with signs that had messages supporting “medical freedom.”

“We began hearing this week about potential walkouts or wildcat strikes,” the union wrote. “We want to be clear. The Union cannot encourage a wildcat strike, withholding our labor, a sick out or walk out in any form, due to the no strike/no lockout clause in our contract.”

The union’s letter to its members said it does not plan to pursue legal action against Boeing at this time. The bargaining and rally came after Boeing announced earlier this week it will require its employees to get vaccinated. Workers must be vaccinated by Dec. 8 or have an approved reasonable accommodation, based on medical or religious beliefs. The forthcoming federal vaccine mandate is expected to apply to roughly half of the county’s workforce.