Defective interfering particle

Defective interfering particles (DIPs) are virus particles that are missing part or all of their genome. Because of these deletions in their genome, DIPs cannot sustain an infection by themselves. Instead, they depend on coinfection with a suitable helper virus. The helper virus provides the gene functions that are absent from the DIPs. The DIP interferes with the helper virus by competing for enzymes that the helper virus requires to multiply. Unfortunately, the interference is not sufficient to eliminate the viral infection, and DIPs are not used clinically.