Question: when did the first meningitis vaccine come out
[{'answer': '1970s', 'provenance': [{'wikipedia_id': '21053494', 'title': 'Meningococcal vaccine', 'start_paragraph_id': 4, 'start_character': 56, 'end_paragraph_id': 4, 'end_character': 61, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '21053494', 'title': 'Meningococcal vaccine', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 344, 'bleu_score': 0.815982801024512, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18391449619032312635}, 'section': 'Section::::Abstract.'}]}]