Starting on Wednesday, April 28, the Portland Expo vaccination clinic will begin offering walk-in vaccinations. Operated by Northern Light Mercy Hospital, the clinic is open each week from Tuesday through Friday from 9 a.m. to 3 p.m. The number of vaccines available on a walk-in basis will be dependent on weekly vaccine shipments. Vaccination appointments can still be scheduled ahead of time at covid.northernlighthealth.org or by calling (207) 204-8551. As a reminder, those with appointments should arrive no more than 10 minutes prior to their scheduled time to reduce the potential for lines outside the facility.