This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2019, Subject name: Social & Preventive Medicine
Which vaccine is effective for Mass vaccination post-disaster? 
Select and explain. 
A. Cholera, B. Typhoid, C. Measles, D. Scrub typhus
C: Measles
Answer: C: Measles 
Explanation: Measles vaccine is effective post-disaster. Incubation period - 10-14 days IP of Vaccine Induced Measles(VIM) - 7 days, hence immunity is provided before the natural infection. The highest risk of transmission post-disaster is of diarrhoeal and respiratory diseases, which have an incubation period of a few days. ABSOLUTELY contraindicated in post-disaster phase for mass vaccination Typhoid Cholera Tetanus .