Alan Perelson Publishes on Success of Prophylactic Antiviral Therapy for SARS-CoV-2
Alan Perelson Publishes on Success of Prophylactic Antiviral Therapy for SARS-CoV-2
Alan Perelson, a LANL scientist and New Mexico Consortium affiliated scientist, recently published his paper titled, Success of prophylactic antiviral therapy for SARS-CoV-2: Predicted critical efficacies and impact of different drug-specific mechanisms of action in PLoS Computational Biology.
As the COVID-19 pandemic continues to drive the search for effective prevention and treatment strategies, researchers have investigated a variety of antiviral drugs that could either treat SARS-CoV-2 infections or prevent infection from occurring altogether. Many of these efforts have focused on repurposing existing antiviral medications that are already approved for other diseases.
In this study, Perelson and his colleagues explored how effective antiviral drugs must be to prevent SARS-CoV-2 infection from becoming established within the body. Rather than relying on clinical trials alone, the team used a mathematical and computational approach to model the earliest stages of viral infection. Using a stochastic model of within-host viral dynamics, they evaluated how different classes of antiviral drugs influence the likelihood of successful infection prevention.
The researchers found that antiviral therapies must achieve a critical level of effectiveness in order to completely block the establishment of infection. The exact threshold depends on the mechanism of action of the drug. Importantly, the study showed that combining multiple antiviral drugs can significantly improve prevention. The most effective combination involved one drug that blocks viral entry into cells and another that enhances the body’s ability to clear viral particles.
Even when antiviral therapies do not reach the critical level needed to completely prevent infection, they can still substantially reduce the risk of infection. The study found that drugs that prevent viruses from entering cells or increase viral clearance are generally more effective at reducing infection risk than drugs that primarily reduce viral production within already infected cells.
Another factor influencing treatment success is the size of the initial viral exposure. The researchers found that larger viral inoculums are more difficult to prevent, while smaller exposures are more susceptible to antiviral intervention. Their model predicted that when the initial exposure is fewer than 10 infectious viral particles, antiviral drugs with an efficacy of 90% or greater can almost certainly prevent infection from becoming established.
The study also highlights the value of antiviral drugs even after infection has occurred. By slowing viral replication and delaying the time required for the virus to reach detectable levels, antiviral treatments may reduce the severity of disease and potentially decrease transmission to others. This delay can provide the immune system with additional time to respond and may lessen the overall impact of the infection.
The findings suggest that prophylactic antiviral therapies could play an important role in protecting individuals who face a high risk of exposure to SARS-CoV-2. Healthcare workers, first responders, and others in high-exposure environments may particularly benefit from preventive antiviral strategies, especially during periods of widespread community transmission.
By combining mathematical modeling with biological insights, this research provides a valuable framework for evaluating antiviral prevention strategies and offers guidance for the development and deployment of future therapies aimed at controlling COVID-19 and other emerging viral diseases.
See the entire paper at: