  The COVID-19 pandemic has influenced the lives of people globally. In the
past year many researchers have proposed different models and approaches to
explore in what ways the spread of the disease could be mitigated. One of the
models that have been used a great deal is the
Susceptible-Exposed-Infectious-Recovered (SEIR) model. Some researchers have
modified the traditional SEIR model, and proposed new versions of it. However,
to the best of our knowledge, the state-of-the-art papers have not considered
the effect of different vaccine types, meaning single shot and double shot
vaccines, in their SEIR model. In this paper, we propose a modified version of
the SEIR model which takes into account the effect of different vaccine types.
We compare how different policies for the administration of the vaccine can
influence the rate at which people are exposed to the disease, get infected,
recover, and pass away. Our results suggest that taking the double shot vaccine
such as Pfizer-BioNTech and Moderna does a better job at mitigating the spread
and fatality rate of the disease compared to the single shot vaccine, due to
its higher efficacy.
