The vaccination requirement was issued in August by executive order and went into effect last week. According to the lawsuit, thousands of county employees have not complied.
The Los Angeles Superior Court lawsuit also alleges the directive exceeds the county's power under the Emergency Services Act and was implemented during proceedings that violated the state's open-meeting law.
Los Angeles County Board of Supervisors Chair Hilda Solis issued an executive order on Aug. 4 requiring the county's 110,000 employees to provide proof of vaccination against COVID-19 by Friday, with exemptions for medical and religious reasons.
"They will risk their jobs rather than violate their conscience and follow a plainly unlawful order," the suit states.
None of the plaintiffs has complied with the vaccine order, the suit states.
"The county must consider and offer reasonable accommodations as a middle ground between individual freedoms and collective rights," the suit states.
LAPD officers sue city over COVID-19 vaccination requirement
"It did not do that. Instead, it viewed this sensitive personal issue through the lens of partisan politics."
A representative for the county issued a statement Monday night regarding the suit brought Friday.
"While we cannot comment on pending litigation ... Los Angeles County is the largest municipal workforce in the nation and we are encouraged that more than 80% of our employees have already registered their vaccination status," the statement read.
The plaintiffs are Sheriff's Department employees Vincent Tsai and Oscar Rodriguez; Probation Department worker Enrique Iribe; Sanitation Department employee Mohamed Bina; Department of Public Health worker Shayne Lamont; and the nonprofit group Protection for the Educational Rights of Kids, which advocates for civil rights, bodily autonomy, medical freedom and other rights, with a particular focus on children and parental rights, according to the suit.
"County residents cannot afford to lose thousands of public employees on a whim. They would be unable to obtain critical public services, including social services that kids and families depend on."
The county "cannot just get rid of the unvaccinated employees who Ms. Solis chastised for not doing their part to end the pandemic," the suit states.
City News Service contributed to this report.