Effectiveness of vaccination and quarantine policies to curb the spread of COVID-19

A pandemic, the worldwide spread of a disease, can threaten human beings from both social and biological perspectives and paralyze existing living habits. To stave off the more devastating disaster and return to normal life, people make tremendous efforts at multiscale levels, from individuals to the global population: paying attention to hand hygiene, developing social policies such as wearing masks, practicing social distancing, quarantine, and inventing vaccines and remedies. Regarding the current severe pandemic, namely the coronavirus disease 2019, we explore the spreading-suppression effect when adopting the aforementioned efforts. In this numerical study, we especially consider quarantine and vaccination since they are representative primary treatments for blocking the spread and preventing the disease at the government level. We establish a compartment model consisting of susceptible (S), vaccinated (V), exposed (E), infected (I), quarantined (Q), and recovered (R) compartments, called the SVEIQR model. We examine the number of infected cases in Seoul and consider three kinds of vaccines: Pfizer, Moderna, and AstraZeneca. The values of the relevant parameters are obtained from empirical data from Seoul and clinical data for the vaccines and estimated through Bayesian inference. After confirming the plausibility of our SVEIQR model, we test various scenarios by adjusting the associated parameters with the quarantine and vaccination policies around the current values. The quantitative results obtained from our model could suggest guidelines for policy making on effective vaccination and social policies.