AUTHOR=Kinyili Musyoka , Munyakazi Justin B. , Mukhtar Abdulaziz Y. A. 

TITLE=To Use Face Masks or Not After COVID-19 Vaccination? An Impact Analysis Using Mathematical Modeling

JOURNAL=Frontiers in Applied Mathematics and Statistics

VOLUME=Volume 8 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2022.872284

DOI=10.3389/fams.2022.872284

ISSN=2297-4687

ABSTRACT=The question of whether to drop or to continue wearing face masks especially after being vaccinated
among the public is controversial. This is sourced by the efficacy levels of COVID-19 vaccines developed,
approved, and in use. We develop a deterministic mathematical model that factors in combination
of COVID-19 vaccination program and wearing of face masks as intervention strategies to curb the spread
of COVID-19 epidemic. We use the model specifically to assess the potential impact of wearing of face
masks especially by the vaccinated individuals in combating further contraction of COVID-19 infections.
Validation of the model is achieved by performing its goodness of fit to the Republic of South Africa’s
reported COVID-19 positive cases data using the Maximum Likelihood Estimation algorithm implemented
in fitR package. We firstly consider a scenario where the uptake of the vaccines and wearing of the face
masks especially by the vaccinated individuals is extremely low. Secondly, we consider a scenario where
the uptake of the vaccines and wearing of the face masks by people who are vaccinated is relatively high.
Thirdly, we consider a scenario where the uptake of the vaccines and wearing of the face masks by the
vaccinated individuals is on the upward trajectory. Findings from the scenario one and the scenario two
respectively indicate highly surging number of infections and low recorded number of infections. For the
scenario three, it shows that increased extent of wearing of the face masks by the vaccinated individuals
at increasing levels of vaccine and face mask average protection results to highly accelerated decrease in
the COVID-19 infections. However, wearing of face masks alone also results in the reduction of the peak
number of the infections at increasing levels of face masks efficacy though the infections delay to clear.