Question: when was the first hepatitis b vaccine given
[{'answer': '1981', 'provenance': [{'wikipedia_id': '12947073', 'title': 'Hepatitis B vaccine', 'start_paragraph_id': 4, 'start_character': 67, 'end_paragraph_id': 4, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '12947073', 'title': 'Hepatitis B vaccine', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 368, 'bleu_score': 0.891621105621859, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3697146872941665844}, 'section': 'Section::::Abstract.'}]}]