This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'One advantage of a live attenuated vaccine is? \nSelect and explain. \nA. It does not produce persistent infections, B. The viral strain does not reve to virulent forms, C. It has an unlimited shelf life, D. It induces a wide spectrum of antibodies', 'role': 'user'}, {'content': 'Answer: D \nExplanation: An advantage of live attenuated vaccines is that they induce a wide spectrum of antibodies. Disadvantages include the possible production of persistent infections, reversion to highly virulent strains and a limited shelf life.', 'role': 'assistant'}]