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: Pediatrics
[{'content': 'Peusis affects which age - \nSelect and explain. \nA. 3-Feb, B. <5, C. 7-May, D. > 10 years', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., < 5 o In prevaccine era, and in countries where immunization is limited the peak incidence of peussis is in children 1-5 years of age, infant accounts for < 15% of cases. o In recent years, where vaccination is employed, approximately one half of cases have occuured in infants younger than 1 year of age and one fouh in adolescent and adults.", 'role': 'assistant'}]