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
You are the MO in charge in a PHC and there has been a plague epidemic in your area. Which of the following measure is the LEAST appropriate for controlling epidemic? 
Select and explain. 
A. Rapid treatment of cases with streptomycin, B. Vaccination of all susceptible individuals, C. Isolation of contacts, D. Early diagnosis and notification
B: Vaccination of all susceptible individuals
Answer: B: Vaccination of all susceptible individuals 
Explanation: After vaccination it takes about 5-7 days for the immunity to develop. So it should be carried out at least a week before the expected outbreak. This vaccination is only used for prevention and not control of outbreak. Also know: Tetracycline is the drug of choice for chemoprophylaxis against plague. Ref: Park, Edition 21, Page - 271.