ABSTRACT: Despite the development of safe and effective vaccines, effective treatments for COVID-19 disease are still desperately needed. Recently, two antiviral drugs have shown to be effective in reducing hospitalizations in clinical trials. In the present work, we use an agent-based mathematical model to assess the potential population impact of the use of antiviral treatments in four countries, corresponding to four current levels of vaccination coverage: Kenya, Mexico, United States (US) and Belgium, with 1.5, 38, 57 and 74% of their populations vaccinated. For each location, we varied antiviral coverage and antiviral effect in reducing viral load (25, 50, 75 or 100% reduction). Irrespective of location, widespread antiviral treatment of symptomatic infections (≥ 50% coverage) is expected to prevent the majority of COVID-19 deaths. Furthermore, even treating 20% of adult symptomatic infections, is expected to reduce mortality by a third in all countries, irrespective of the assumed treatment efficacy in reducing viral load. Our results suggest that early antiviral treatment is needed to mitigate transmission, with early treatment (within two days of symptoms) preventing 50% more infections compared to late treatment (started on days 3 to 5 after developing symptoms). Our results highlight the synergistic effect of vaccination and antiviral treatment: as vaccination rate increased, antiviral treatment had a bigger impact on overall transmission. These results suggest that antiviral treatments can become a strategic tool that, in combination with vaccination, can significantly control SASRS-CoV-2 transmission and reduce COVID-19 hospitalizations and deaths.Significance
Several antiviral drugs have shown to be highly effective in reducing hospitalizations in clinical trials. We used a mathematical model to assess the potential impact of antiviral treatments in four different countries with vastly different proportions of vaccinated individuals (Kenya, Mexico, United States and Belgium). Irrespective of location, widespread antiviral use in adult symptomatic infections can prevent most deaths. Furthermore, a third of deaths could be averted by treating only 20% of adult symptomatic infections. We identified a synergistic effect of antiviral treatment and vaccination by which countries with larger proportion of their population vaccinated benefited more from antiviral treatments. Our results show that antiviral treatments can be an extremely useful tool to reduce COVID-19 deaths and curtail SARS-CoV-2 transmission.
