Maintaining face mask use before and after achieving different COVID-19 vaccination coverage levels: a modelling...

Area of Science:

• Epidemiology
• Public Health Policy
• Health Economics

Background:

• Face mask mandates were crucial during the COVID-19 pandemic.
• Relaxing mask policies is increasing as vaccination rates rise.
• Subsequent COVID-19 surges necessitate evaluating continued mask use.

Purpose of the Study:

• To assess the economic value of maintaining indoor face mask use in the USA.
• To analyze mask efficacy at different COVID-19 vaccination coverage levels.
• To determine optimal durations for face mask policies post-vaccination.

Main Methods:

• A Monte Carlo simulation model of the US population and SARS-CoV-2 spread was developed.
• Simulation experiments compared outcomes with and without face masks until target vaccination coverage.
• Scenarios varied vaccination coverage (70-90%), achievement dates, and mask discontinuation timing.

Main Results:

• Maintaining face mask use until target vaccination coverage was cost-effective and often cost-saving.
• Masks were cost-effective at ≤$1.25 per person per day.
• Continuing mask use for 2-10 weeks post-vaccination was cost-effective, especially during winter.

Conclusions:

• Maintaining face mask use until and shortly after achieving vaccination targets is strongly supported.
• Mask policies can be cost-effective and cost-saving, particularly with emerging variants.
• The value of face masks is amplified by factors like new variants and waning vaccine effectiveness.