Antiviral Agents: Why Not a “Penicillin” for Viral Infections?

Abstract

The question asked most frequently by the lay person of someone involved in research on antiviral agents is “When are you going to do something about the common cold?”; the lay press contributes “Why isn’t there something like penicillin for the treatment of viral infections?” The answer usually given is a simple explanation of virus replication and the difficulty of disrupting viral replication without affecting normal cellular functions. For many years it was believed that virus production depended exclusively on cellular metabolic processes. However, this pat answer is only a partial response; it certainly is no longer adequate for the virologist. We have seen from the preceding presentations that many viruses have specific targets which can be identified and characterized, and for which specific blocking agents can be synthesized. Why, then, have we not been more effective in developing new antiviral agents? Again, there is a simple answer — clinicians and virologists have been skeptical about the potential of antivirals, believing effective antivirals would also be toxic; further, we are only now learning sufficient details of the molecular biology of viruses to identify specific blocks. Thus, the effort to date to develop new agents has been minimal. To be successful, greater effort must be expended. All the compounds identified thus far are largely a result of serendipity. None are truly the result of a concentrated effort to develop targeted antiviral agents against a specific virus. Most have come through large screening programs with the production analogs of those substances which show some promise.