A third dose of certain COVID-19 vaccines is now being given to qualifying patients in the Mayo Clinic health system.
The doses currently are intended for patients 12 and older who have compromised immune systems, as a result of HIV infection or other causes.
Anyone getting the third shot has to wait at least 28 days after a vaccination with the Moderna or Pfizer vaccine.
Mayo says anyone who got the one-dose Johnson and Johnson vaccine does not need another shot at this time.
Patients of Mayo who qualify for the third dose are being contacted on-line and by mail.