National Guard Medic, Ross Davison, speaks to Greg Bryson, 63, after Davison administered a Johnson & Johnson COVID-19 vaccine to him at the drive-through vaccination site at Six Flags Hurricane Harbor (Waterworld) in Concord, Calif., on Wednesday March 31, 2021. (Ray Saint Germain/Bay City News)

Contra Costa County rescinded its order Tuesday requiring first responders and other emergency personnel to be vaccinated against COVID-19 or test regularly for the virus.

The county first issued the health order Aug. 13, 2021, amid a surge in cases tied to the then-novel delta variant. Contra Costa Health Services removed the requirement Tuesday, effective immediately.

The health order applied to law enforcement officers, firefighters and emergency medical personnel who respond to emergencies at facilities that have a high risk of developing a COVID outbreak like hospitals, jails and nursing homes.

Workers like ambulance drivers who provide medical transport to and from the relevant facilities even in non-emergency situations were also subject to the vaccination or testing requirement.

Tuesday’s order also rescinds a related requirement, which the county issued in December, that relevant workers get a booster vaccine dose if eligible to do so.

In rescinding the order, county health officer Dr. Ori Tzvieli argued that it was issued at a different time in the pandemic and mutations of the virus are now the dominant strains both countywide and across the Bay Area.

“While the COVID-19 vaccines and boosters remain excellent tools for substantially reducing the risk of severe disease and death, as a result of the mutations, the protection against infection and transmission offered by the current COVID-19 vaccines has diminished,” Tzvieli said. “As a result, both vaccinated and unvaccinated people are becoming infected with current circulating strains of the virus.”

Tzvieli also pointed to the county’s declining COVID hospitalization rate and the wider availability of medical treatments for COVID as reasons why screening for vaccination status and testing is no longer necessary.

As of Wednesday, 83.7 percent of county residents have completed their initial vaccination series. In addition, 54.2 percent have received at least one booster vaccine dose to fortify their immune response.