The first week of a tri-weekly pop-up coronavirus vaccine clinic will be held at the Healdsburg Farmers’ Market today. The clinic will run from 9 a.m. until 12:30 p.m., and it will be set up behind the information booth facing the plaza. Today will be the first session, but the clinic will continue to give doses of the Pfizer vaccine at the Farmer’s Market every three weeks. Alliance Medical Center will be administering the vaccines.