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: Social & Preventive Medicine
[{'content': 'Which one of the following vaccines is contraindicated in pregnancy? \nSelect and explain. \nA. MMR, B. Rabies, C. Hep B, D. None', 'role': 'user'}, {'content': "Answer: A \nExplanation: MMR is a live vaccine prepared from live and generally attenuated organisms by passing repeatedly in the laboratory in tissue culture and thus it has lost their capacity to cause a full blown disease but retain their propeies of immunogenicity. Live vaccines are contraindicated in pregnancy considering the risk of teratogenic harm to the fetus. Rabies and Hepatitis B vaccines are killed or inactivated vaccines and no such contraindication exists to their use in pregnancy. Ref: Park's Textbook of Preventive and Social Medicine By K. Park, 19th Edition, Pages 97-8; Side Effects of Drugs Annual By Jeffrey K. Aronson, Pages 581-582; Immunology for The Health Sciences By Nicholas J. Vardaxis, Pages 101-4", 'role': 'assistant'}]