The virus binds to a receptor on the cell surface. This is done at a specific site, present on the virus. This viral site binds with the host receptor site. So, antiviral medication can be designed in such a way that it binds to the viral site or to the host cell receptor. As the result, viral-host cell binding will be disrupted; the virus will not be able to enter the host cell.
So, you can say that the viral process targeted for inhibition is host binding, that is the very first step after viral infection in the body.
Such medications also come under the category of ‘entry inhibiting/blocking’ drugs.
It is important to note that the second type of antiviral medication is also there; that blocks the uncoating of the virus inside the host cell. This medication can also be applied in the above case.
But the first medication is the first line of defense and it would be better to use it. This is because all RNA viruses are not coated.