Query: When was my last flu shot?, FHIR Resource: {'resourceType': 'Immunization', 'status': 'completed', 'vaccineCode': {'coding': [{'system': 'http://hl7.org/fhir/sid/cvx', 'code': '140', 'display': 'Influenza, seasonal, injectable, preservative free'}], 'text': 'Influenza, seasonal, injectable, preservative free'}, 'patient': {'reference': 'urn:uuid:fa9ef1cf-f8c8-64b8-c88a-db2e07f39a28'}, 'occurrenceDateTime': '1988-12-21T18:28:02+05:30', 'primarySource': True}