This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraindications, AEFIs, Subject name: Social & Preventive Medicine
Which of the following regarding oral polio vaccine (OPV) is not true? 
Select and explain. 
A. Useful in epidemics, B. Excretion of virus in stools may cause disease to the unimmunized, C. Rapid antibody response, D. Protective even in the presence of maternal antibodies
B: Excretion of virus in stools may cause disease to the unimmunized
Answer: B: Excretion of virus in stools may cause disease to the unimmunized 
Explanation: Excretion of virus in stools provides immunity to unimmunized (Herd Immunity) OPV or Sabin type vaccine: Live attenuated Given orally Immunity is both humoral and intestinal Induces antibodies quickly Prevents not only paralysis, but also intestinal reinfection Can be effectively used in controlling epidemics (herd immunity); Even a single dose elicits substantial immunity. Easy to manufacture Cheaper Required to be stored & transpoed at sub zero temperatures, unless stabilized