So once the cell starts to break down the idea is that the virus, bacteria or any germ can now get in the cell and start hijacking cell machinery to start a replication process...
This is not fact though, as there is an abundance of evidence that the process of cellular breakdown is a signal for bacteria and polymorphic exosomes to come to the sight of cell breakdown and are used by the body to clean up the debris.
For some strange reason people who are taught virology methods don't understand this and are retarded to the acceptance of this knowledge.