This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Epidemiology, Subject name: Social & Preventive Medicine
Post exposure, Measles vaccine must be given within 
Select and explain. 
A. 3-4 days, B. 10-Jul, C. 10-14 days, D. 1-6 months
A: 3-4 days
Answer: A: 3-4 days 
Explanation: - IP of measles - 10 days - IP of vaccine induced measles - 7 days - For providing protection vaccine requires only 6-7 days. - So, vaccine should be used within 3-4 days of exposure.