Date of Award

January 2021

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Saad B. Omer

Second Advisor

Sameul M. Jenness


Background: Widespread use of cloth or medical masks by the public contributed to decreased transmission of SARS-CoV-2 in the United States throughout the COVID-19 pandemic in 2020 and 2021. Vaccinations granted Emergency Use Authorization in late 2020 and early 2021 offered another measure for preventing morbidity and mortality from COVID-19. Combining pharmaceutical and nonpharmaceutical interventions was estimated to further decrease transmission. However, pressure to repeal mask mandates is growing as more and more people are vaccinated. Therefore, it is vital to understand how changing masking behaviors and increasing proportion of individuals vaccinated impact the transmission dynamics of SARS-CoV-2.

Methods: I evaluated how changes in masking and vaccinated proportions over time impacted cases, hospitalizations, and deaths. Outcomes were measured under different constant masking levels for the duration of the epidemic. Outcomes were also measured as masking rate decreased continuously in the vaccinated and unvaccinated subpopulations as vaccinated proportion increased in the full population. These scenarios were both tested in the presence of variants of concern with a 50% higher R0 value.

Results: Higher masking proportions were consistent with lower cases, hospitalizations, and deaths. Decreasing masking continuously over time led to significantly higher cases than maintaining high masking throughout. This was seen more strongly when making decreased in the unvaccinated subpopulation, as compared to the vaccinated subpopulation. Presence of variants of concern exacerbated these trends, leading to high cases, hospitalizations, and deaths when masking was relaxed.

Conclusion: Reducing masking in any group leads to an increase in cases, hospitalizations, and deaths, particularly in the presence of highly transmissible variants.


This is an Open Access Thesis.

Open Access

This Article is Open Access