Final answer:
An antiviral is a class of medication used for treating viral infections. They are most effective when used early in the course of the infection. Antivirals avoid damaging the host by targeting viral proteins that are not present in healthy cells.
Step-by-step explanation:
An antiviral is a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do not destroy their target pathogen; instead, they inhibit its development.
Antiviral drugs are most effective when used early in the course of the viral infection, ideally before the virus has had a chance to replicate extensively in the body. By targeting specific viral proteins, antivirals can interfere with the virus's ability to replicate and spread within the host.
Antivirals avoid harming the host by specifically targeting viral proteins that are not present in healthy host cells. These targeted proteins are encoded by viral genes, and by blocking their actions, antiviral drugs can inhibit viral growth without damaging the host.