Could widespread use of antiviral treatment curb the COVID-19 pandemic? A modeling study

Abstract

Background: Despite the development of safe and effective vaccines, effective treatments for COVID-19 disease are still urgently needed. Several antiviral drugs have shown to be effective in reducing progression of COVID-19 disease.

Methods: 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 with different demographic structure and current levels of vaccination coverage: Kenya, Mexico, United States (US) and Belgium. We analyzed antiviral effects on reducing hospitalization and death, and potential antiviral effects on reducing transmission. For each country, we varied daily treatment initiation rate (DTIR) and antiviral effect in reducing transmission (AVT).

Results: Irrespective of location and AVT, widespread antiviral treatment of symptomatic adult infections (20% DTIR) prevented the majority of COVID-19 deaths, and recruiting 6% of all adult symptomatic infections daily reduced mortality by over 20% in all countries. Furthermore, our model projected that targeting antiviral treatment to the oldest age group (65 years old and older, DTIR of 20%) can prevent over 30% of deaths. Our results suggest that early antiviral treatment (as soon as possible after inception of infection) is needed to mitigate transmission, preventing 50% more infections compared to late treatment (started 3 to 5 days after symptoms onset). Our results highlight the synergistic effect of vaccination and antiviral treatment: as the vaccination rate increases, antivirals have a larger relative impact on population transmission. Finally, our model projects that even in highly vaccinated populations, adding antiviral treatment can be extremely helpful to mitigate COVID-19 deaths.

Conclusions: These results suggest that antiviral treatments can become a strategic tool that, in combination with vaccination, can significantly reduce COVID-19 hospitalizations and deaths and can help control SARS-CoV-2 transmission.

Keywords: Agent-based model; Antiviral treatment; COVID-19; Mathematical model; SARS-CoV-2.

Fig. 1

Percentage of deaths averted for A Kenya, B Mexico, C United States and D Belgium. Percentage of deaths averted assuming an epidemic wave with parameters similar to those of the Omicron epidemic wave (transmissibility, vaccine effectiveness, and vaccination coverage) when compared to a baseline of no antiviral treatment. For each country, the colors represent four possible values of AVT (25, 50, 75 or 100% reduction in viral transmission in treated symptomatic individuals) and a daily treatment initiation rate (DTIR) of 2–100% of adult symptomatic individuals within the first 5 days of symptoms

Fig. 2

Percentage of deaths averted for targeted interventions for A Kenya, B Mexico, C United States and D Belgium. Percentage of deaths averted assuming an epidemic wave with parameters similar to those of the Omicron epidemic wave (transmissibility, vaccine effectiveness, and vaccination coverage) when compared to a baseline of no antiviral treatment using antiviral treatment in targeted age groups. For each country, the colors represent four possible values of AVT (25, 50, 75 or 100% reduction in viral transmission in treated symptomatic individuals) and targeting the antiviral treatment to symptomatic adults older than 18, 30, 50 or 65 years of age with a daily treatment initiation rate of 20%

Fig. 3

Percentage of infections averted for A Kenya, B Mexico, C United States and D Belgium. Percentage of infections averted (compared to a baseline of no antiviral treatment) assuming an epidemic wave with parameters similar to those of the Omicron epidemic wave (transmissibility, vaccine effectiveness, and vaccination coverage). For each country, the colors represent four possible values of AVT (25, 50, 75 or 100% reduction in viral transmission in treated symptomatic individuals) and a daily treatment initiation rate (DTIR) of 2–100% of adult symptomatic individuals within the first 5 days of symptoms

Fig. 4

Epidemic curves assuming antiviral treatment coverage of 10–100% of eligible symptomatic individuals. Daily new infections assuming no antiviral treatment (Baseline) or assuming coverage of 10–100% of eligible symptomatic individuals in A Kenya, B Mexico, C United States and D Belgium. Here, we assumed an epidemic wave with parameters similar to those of the Omicron epidemic wave (transmissibility, vaccine effectiveness, and vaccination coverage). For each location, each column represents a different value of AVT (25, 50, 75 or 100% reduction in viral load)

Fig. 5

Percentage of deaths averted assuming early or late treatment initiation. Percentage of deaths averted (compared to a baseline of no antiviral treatment) for A Kenya, B Mexico, C United States and D Belgium for early (within the first two days of symptoms, left column) or late (between days 2 and 5 of symptoms, right column) treatment. Here, we assumed an epidemic wave with parameters similar to those of the Omicron epidemic wave (transmissibility, vaccine effectiveness, and vaccination coverage). For each country, the colors represent four possible values of AVT (25, 50, 75 or 100% reduction in viral transmission in treated symptomatic individuals) and covering 10–100% of eligible symptomatic individuals