Why do viruses show different susceptibilities to antivirals?

Why do viruses show different susceptibilities to antivirals?

• A. Differences in host factors determine susceptibility.
• B. All viruses share identical replication steps.
• C. Antivirals target broad host pathways affecting all viruses equally.
• D. Differences in replication steps targeted by antivirals and potential for resistance; not all viruses rely on the same processes.

Answer: (D)

Viruses show different susceptibilities to antivirals because antivirals work by blocking specific steps in a virus’s replication, and different viruses rely on different enzymes and pathways to replicate. If a drug targets a particular viral enzyme or process, only viruses that use that same step will be affected. Others that don’t depend on that enzyme or use a different replication strategy won’t be as susceptible. Additionally, viruses can mutate the targeted site or bypass the blocked step, leading to resistance; this makes some viruses less affected by a drug over time. Some antivirals also target host cell factors, but those effects can vary across viruses, further contributing to differing susceptibilities.

Viruses show different susceptibilities to antivirals because antivirals work by blocking specific steps in a virus’s replication, and different viruses rely on different enzymes and pathways to replicate. If a drug targets a particular viral enzyme or process, only viruses that use that same step will be affected. Others that don’t depend on that enzyme or use a different replication strategy won’t be as susceptible. Additionally, viruses can mutate the targeted site or bypass the blocked step, leading to resistance; this makes some viruses less affected by a drug over time. Some antivirals also target host cell factors, but those effects can vary across viruses, further contributing to differing susceptibilities.