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
Vaccine with highest efficacy - 
Select and explain. 
A. Measles, B. DPT, C. Oral typhoid, D. Tetanus
A: Measles
Answer: A: Measles 
Explanation: Ans. is 'a' i.e., Measles Amongst the given options only measles vaccine induce effective immunity after a single dose. o Efficacy of measles vaccine is 95% after a single dose. o All others require multiple doses. o Efficacy of DPT vaccine is around 70%. o 3 years efficacy of three doses of oral typhoid vaccine is 50-60%. o In most clinical trials efficacy of tetanus has ranged from 80-100% - www.whom.tht.