Medical researchers have long wanted a generic anti-viral agent that works on most viruses, much like antibacterials (such as penicillin) work on bacterial infections. The main way we protect against viruses is to inject a vaccine consisting of a harmless or dead version of the virus. This causes the body to generate antibodies and allows it to react more quickly when exposed to the real virus. The problem is that this doesn’t work on new or mutated viruses (think SARS or the ever-changing flu virus).
Now researchers have developed a promising anti-viral drug that should work on most existing viruses as well as any new ones. Rather than prepping the body’s immune system, it works directly on the virus and prevents it from replicating. And as an added bonus, it will be quite difficult for a virus to develop an immunity to the drug. The linked article has more details.