Antiviral drugs

An essential component of the pandemic preparedness toolbox

While vaccination can effectively control viral diseases, there will always be a time gap before a vaccine can be produced and distributed after the emergence of a new pathogen. It is also possible that vaccines cannot be developed against some of the future emerging viruses. In this context, directly-acting antiviral drugs (i.e., drugs targeting conserved and essential functions in virus replication) offer an important but underappreciated possibility for prophylactic and therapeutic intervention, particularly during the time frame needed for vaccine development. They will allow the treatment of infected patients and may save the lives of those falling critically ill. As they will reduce virus shedding by these early patients, the R0 may be pushed below 1, which would be an essential contribution to efforts to curb an epidemic and avoid worldwide spread.

The conserved nature of many of the targets of directly-acting antiviral drugs (including the active sites of viral proteases and polymerases) enhances the chance of broad(er)-spectrum activity because these targets are much less subjected to direct immune selection and tend to evolve more slowly due to structure-function constraints. Thus, directly-acting antiviral drugs can be a critical tool to reduce the impact of virus outbreaks in their earliest phase or even to contain them before becoming a more widespread problem.

Drug binding to the SARS-CoV-2 RNA polymerase. Shannon et al. Nat Commun 13, 621 (2022). https://www.nature.com/articles/s41467-022-28113-1