Challenges in Developing Effective Antiviral Drugs with Minimal Side Effects

Challenges in developing effective antiviral drugs with minimal side effects to the patient include

A) drugs can be easily delivered to reach viruses within host cells.
B) viruses have many more chemically distinct targets than living pathogens.
C) only the attachment stage of the viral life cycle is a suitable target for antiviral drug action.
D) the immune system is rarely successful in ending viral infections so there is no natural model to work from.
E) viruses use the cell's own machinery and metabolism for replication.