COVID-19 vaccination clinic for the public opened up at the Centre on Barton Thursday and is set to be another important piece of the city’s plan to administer an anticipated influx of vaccine doses over the next few months.In a release, public health said demand is expected to be fueled by the impending approval of a shot for children ages five to 11, likely on Friday, and the possibility that third doses will be around in January for anyone in the eligible 12-plus population who wants it.The new fixed clinic at 1211 Barton St.