Thousands of Los Angeles County employees are being put on notice in the weeks after a COVID-19 vaccine mandate deadline passed.

County employees had by Oct. 1 to submit proof of their vaccination status. The order, announced by the Los Angeles County Board of Supervisors in early August, encompasses sheriff’s deputies, firefighters, hospital staff, social workers and others.

As of Tuesday, 77.7% of the county’s 101,575 current employees are fully vaccinated, county data shows. A dozen departments are reporting vaccination rates of at least 90%, while nearly half of the departments are reporting vaccination rates between 80% and 89%. Seven departments are below 80%.

Nearly 10% of all county employees have yet to register to submit their vaccination status.

Those who fail to get vaccinated or submit a request for a medical or religious exemption could face disciplinary action, including termination.

In the weeks since the vaccine mandate deadline passed, the county has been sending notices in waves to non-compliant employees, advising them that they have 45 days to register as fully vaccinated or request an accommodation. After that point, the employees will be put on a five-day suspension and have 30 days upon return to comply.

Failure to comply within that time period “may result in disciplinary action and continued noncompliance may result in further disciplinary action, up to and including discharge from County service,” the notice states.

As of Oct. 12, unvaccinated employees are also required to undergo weekly COVID-19 testing until submitting proof of vaccination and could face disciplinary action for failing to get tested.

The sheriff’s department has the lowest rate of compliance, with 52% of members fully vaccinated, the county data shows. Over 20% of the 16,070-person department has yet to register to submit a vaccination status.

Los Angeles County Sheriff Alex Villanueva, who has been a vocal critic of the vaccine mandate, warned in a letter to the Los Angeles County Board of Supervisors last week that the department stands to lose a “substantial” number of employees over the policy.

“People are not happy with the vaccine mandate,” Villanueva told reporters during a press briefing Tuesday, attributing hesitancy among sworn staff to a lack of “faith in a vaccine.”

“Some of it is driven by a political ideology. Some of it might be irrational, some people have legitimate reasons why they don’t trust the vaccine,” he said.

As notices are rolling out, the county has continued to address vaccine hesitancy.

“We’re encouraging vaccination through an extensive internal communications campaign, including town hall meetings with experts, weekly fliers, messages from County leaders, meetings with our labor partners and other messaging that we are continuing to expand,” Jesus Ruiz, a spokesperson for the Los Angeles County Chief Executive Office, told ABC News in a statement.

County employees are not the only ones subject to a vaccine mandate. Workers in adult and senior care facilities and in-home direct care settings must be fully vaccinated by Nov. 30 under a state order. In the city of Los Angeles, city employees, including police officers, as well as public school staff and students, have vaccine requirements.

Proof of vaccination is also required to enter or work in indoor portions of bars, lounges, nightclubs, breweries, wineries and distilleries in Los Angeles County.

County health officials stressed the importance of vaccination Tuesday, as COVID-19 transmission remains “substantial” heading into the holiday season.

“While transmission is substantial, we need to continue layering on protections, understanding that significant spread of the virus affects unvaccinated individuals and increasingly results in post-vaccination infections among those vaccinated,” Barbara Ferrer, director of the Los Angeles County Department of Public Health, said in a statement. “Substantial spread also creates a fertile breeding ground for new variants that can threaten our progress to date.”