This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
In which of these condition is Post exposure prophylaxis not useful 
Select and explain. 
A. Measles, B. Rabies, C. Peussis, D. Hepatitis B
C: Peussis
Answer: C: Peussis 
Explanation: The merit of Hyperimmune globulin in peussis prohylaxis has yet to be established. So far there is no evidence of its efficacy in well-controlled trials. Post exposure prophylaxis of: H.influenza B: Rifampicin * 4 days Hepatitis A: Human normal Immunoglobulin Hepatitis B: Human specific Immunoglobulin Meningococcal meningitis: Rifampicin 600 mg BD * 2 days OR Meningococcal vaccine Rabies: Human normal Immunoglobulin + Vaccine Tetanus: Human normal Immunoglobulin + Vaccine Measles: Vaccine within 3 days. Ref: Park 25th edition Pgno: 174