I am no expert on viruses but I believe that most relief treatments will target the symptoms like a fever (unlike antibiotics for bacterial infections which fight the bacteria directly). Our immune system is the best defense against viruses.
Some viruses can be targeted by vaccines. Viruses normally have lots of things that stick out on their outer surface. These usually help them stick to and hold onto the cells in our bodies so that they can infect us. But they are also the parts that we can design vaccines against, which means that when your body spots them floating around they can tell call on antibodies to come along, bind to those molecules on the surface of the virus and break it down.
Antibiotics don’t work against viral infections, so we shouldn’t be taking them for things like the flu