What do you mean by "cure"? And in what sense is sofosbuvir (assuming that is what you mean) a cure for hepatitis C, but acyclovir is not a cure for varicella zoster?
Acyclovir definitely seemed to help when i had chickenpox!
It treats the symptoms but the virus is still active:
"It can treat herpes virus infections, including shingles and genital herpes. It can also treat chickenpox. This medication does not cure herpes, but may prevent herpes sores or blisters."
"It can treat herpes virus infections, including shingles and genital herpes. It can also treat chickenpox. This medication does not cure herpes, but may prevent herpes sores or blisters."