What is the primary mechanism employed by antiviral drugs?

Antiviral drugs primarily work by inhibiting the replication of viruses, which is essential for controlling viral infections. When a virus infects a host cell, it uses the host's cellular machinery to replicate itself, leading to more viral particles being produced. This replication process is crucial for the spread and persistence of the infection within the host.

Antiviral medications target various stages of the viral life cycle, such as preventing the virus from entering the host cell, blocking the viral enzymes necessary for replication, or interfering with the assembly of new viral particles. By effectively halting the replication process, these drugs reduce the viral load within the body, thereby alleviating the severity of the infection and allowing the host's immune system a better opportunity to combat the virus.

The other options do not encapsulate the primary action of antiviral drugs. While boosting the immune response can be a beneficial strategy in some treatment scenarios, it is not the primary mechanism of action for antiviral drugs themselves. Destroying infected cells relates more to certain treatments like chemotherapy or treatments for cancer, and neutralizing toxins refers more to the action of some antibiotics and antitoxins rather than antiviral medications. Thus, focusing on the inhibition of viral replication is key to understanding how antiviral drugs function.