Abstract
Using the recently proposed Susceptible-Asymptomatic-Infected-Vaccinated-Removed (SAIVR) model, we study the impact of key factors affecting COVID-19 vaccine rollout effectiveness and the susceptibility to resurgent epidemics. The SAIVR model expands the widely used Susceptible-Infectious-Removed (SIR) model for describing epidemics by adding compartments to include the asymptomatic infected (A) and the vaccinated (V) populations. We solve the model numerically to make predictions on the susceptibility to resurgent COVID-19 epidemics depending on initial vaccination coverage, importation loads, continuing vaccination, and more contagious SARS-CoV-2 variants, under persistent immunity and immunity waning conditions. The parameters of the model represent reported epidemiological characteristics of the SARS-CoV-2 virus such as the disease spread in countries with high levels of vaccination coverage. Our findings help explain how the combined effects of different vaccination coverage levels and waning immunity lead to distinct patterns of resurgent COVID-19 epidemics (either surges or endemic), which are observed in countries that implemented different COVID-19 health policies and achieved different vaccinated population plateaus after the vaccine rollouts in the first half of 2021.
Keywords: COVID-19 vaccines; SARS-CoV-2; compartmental model; resurgent epidemics; vaccination coverage; waning immunity.
【저자키워드】 SARS-CoV-2, COVID-19 vaccines, compartmental model, Waning Immunity., vaccination coverage, resurgent epidemics, 【초록키워드】 COVID-19, COVID-19 vaccine, vaccination, Immunity, susceptibility, Epidemics, Spread, Coverage, Health, Characteristics, Asymptomatic, SARS-CoV-2 variants, Effectiveness, epidemiological, Endemic, waning immunity, help, key factor, contagious, parameter, Effect, populations, country, initial, include, reported, the disease, the vaccine, conditions, explain, affecting, expand, the SARS-CoV-2 virus, 【제목키워드】 COVID-19, modeling,