instruction: when did patient 19627 last receive prescriptions for vancomycin since 01/2101?
response: SELECT prescriptions.startdate FROM prescriptions WHERE prescriptions.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 19627) AND prescriptions.drug = 'vancomycin' AND STRFTIME('%y-%m', prescriptions.startdate) >= '2101-01' ORDER BY prescriptions.startdate DESC LIMIT 1