Vials of the Pfizer coronavirus vaccine, which were used to vaccinate Alameda County law enforcement officials at the Alameda County Sheriff's Department's Regional Training Center in Dublin, Calif. on February 18, 2021. (Eli Walsh/Bay City News)

Some Bay Area counties temporarily paused COVID-19 booster vaccinations Thursday in anticipation of the arrival of new vaccines targeting strains of the virus’ omicron variant.

Alameda, Marin, San Mateo, Santa Clara and Sonoma counties all paused their booster vaccination efforts, electing to resume them later this month when shipments of the omicron-specific vaccines begin to arrive.

The decision comes one day after the U.S. Food and Drug Administration updated its emergency authorizations of the Moderna and Pfizer vaccines to allow for the omicron-specific booster, which targets the BA.4 and BA.5 subvariants while still protecting against the original COVID virus strain as well.

The new vaccines, which are only approved as boosters, are likely to become available as soon as next week, pending the expected approval of the U.S. Centers for Disease Control.

However, under the FDA’s authorization, the new vaccines will be used for all future booster vaccinations of people ages 12 and up while the original mRNA vaccines targeting only the original COVID strain will be authorized for initial vaccine series as well as boosters for children between 6 months and 11 years old.

Sonoma County Health Officer Dr. Sundari Mase said the pause of booster vaccinations will ensure that county residents get the most up-to-date vaccine formula available.

“I urge anyone who is eligible to get the new boosters once they are available,” Mase said. “This is our best tool to keep the community safe through the fall and winter.”

The new Moderna booster will be available to adults while the new Pfizer booster will be available to people ages 12 and older.

Booster vaccinations are expected to proceed in Contra Costa County, according to a county spokesman, while San Mateo County plans to resume administering boosters the week of Sept. 12. Alameda County expects to begin administering the new boosters as soon as the end of next week.

“We are working to make sure residents have access to the new booster shots when they become available and to reopen clinics as soon as possible,” said Lizelle Lirio de Luna, the director of San Mateo County Health’s Family Health Services Division.

People will be eligible for one dose of the omicron-specific boosters if it has been at least two months since completing their initial vaccination series.

Vaccination appointments can be scheduled statewide at https://myturn.ca.gov.