One virus particles prevents multiplication of 2nd virus. This phenomena is:

Viral interference Interference in which infectionof a cell by one virus inhibits simultaneous or subsequent infection by another virus. Most important 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 in controlling poliomyelitis outbreaks by introducing into the population, the live attenuated poliovirus vaccine.