Why is it challenging to selectively target viruses with antiviral drugs?

• A. Viruses possess their own ribosomes, which are resistant to most drugs.
• B. Viruses rely on host cell machinery for replication, making it difficult to target them without harming host cells.
• C. Viruses have a thick peptidoglycan cell wall that prevents drug entry.
• D. Viruses can survive independently outside host cells, making them inaccessible to drugs.

Answer: (B)

Verified step by step guidance

1. Understand that antiviral drugs aim to inhibit viral replication without damaging the host's cells.
2. Recognize that viruses lack many of their own metabolic processes and instead use the host cell's machinery, such as ribosomes, to replicate.
3. Since viruses depend on host cell components, targeting viral replication often risks harming the host cells, leading to toxicity.
4. Note that unlike bacteria, viruses do not have structures like peptidoglycan cell walls, so drugs targeting such structures are ineffective against viruses.
5. Conclude that the main challenge in selectively targeting viruses is their reliance on host cell machinery, which limits the availability of unique viral targets for drugs.