Sonoma County is making COVID-19 booster shots available for eligible seniors, health care workers, public safety personnel and others who are at increased risk for COVID-19 exposure and transmission, county officials announced Friday.

The booster shots will be available to those who received the second dose of the two-shot Pfizer-BioNTech vaccine at least six months ago.

County officials said the county is following the Centers for Disease Control and Prevention recommendation that people 65 years and older and people aged 50 to 64 with certain underlying medical conditions should receive a booster shot.

People 18 to 49 who are at high risk of severe COVID-19 due to underlying medical conditions and people aged 18 to 64 who are at increased risk of exposure and transmission due to their occupational and institutional setting also may receive a booster shot.

Those who qualify for a booster shot under the federal guidelines are encouraged to contact their primary care doctor, local pharmacy or visit to schedule a shot.

County officials reported that as of Friday, 331,957 county residents aged 12 and older were fully vaccinated against COVID-19. That equates to 77 percent of the county’s eligible population. The county reported 30,854 residents have been partially vaccinated.