Question

In what two ways van a virus manage to maintain a persistent infection

Answer 1

Though the exact mechanism of the virus doing persistent infection isn't clear but the two ways it can do persistent infection are.
1. Reducing the defence (immunity) of the host
2. The killing power of the virus. The increased killing of cells of the host by the virus.

Explanation.
1. When host is attacked by any virus ,the host body produces antibodies against the infection. If the host's body is unable to produce enough immunity cells then the viral infection re attacks the host and cause persistent infection.
2. The increased power of killing of the viruses depecits the capacity of the virus to produce viral proteins and toxins for the host and hence killing it's cells and tissues.