CDC has recommended third doses of COVID-19 vaccine for those who are moderately to severely immunocompromised due to certain specific conditions:
  • Been receiving active cancer treatment for tumors or cancers of the blood
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
  • Moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Advanced or untreated HIV infection
  • Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response

Third doses of COVID-19 vaccine are now available by appointment at Public Health Department clinics for SLO County residents who meet these criteria. Residents who schedule an appointment will self-attest to their specific condition. To schedule an appointment, visit or call (833) 422-4255 to choose your location, time, and vaccine type.

Please note: third doses are not available as walk-ins or at mobile/pop-up clinics.

You may also contact your local pharmacy or health care provider to learn about their process for providing third doses of vaccine.

Third Dose FAQs