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: Microbiology
One virus paicles prevents multiplication of 2nd virus. This phenomena is: 
Select and explain. 
A. Viral interference, B. Mutation, C. Supervision, D. Permutation
A: Viral interference
Answer: A: Viral interference 
Explanation: Ans. (a) Viral interference Ref. Ananthanarayan 8/e, p 438, 9/e, p 439 Viral interference "Interference in which infection of a cell by one virus inhibits simultaneous or subsequent infection by another virus." Most impoant mediator of interference is interferon. Interference produced by destruction of cell receptors is seen with myxoviruses and enterovirus. It is applied in the field in controlling poliomyelitis outbreaks by introducing into the population, the live attenuated poliovirus vaccine. Remember: Interference is Nongenetic interaction.