You can go online or on your Boston Children's patient portal or call 617-919-7102 to schedule an appointment. The phone lines are open 7 a.m. to 8 p.m. Tufts Medical Center's Pediatric (5-11 year olds) COVID-19 Vaccine Clinic. Location: 800 Washington St., Tye Pavilion 1st floor. Hours: Monday - Friday, 8 a.m. to 5 p.m..