Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are currently administered in South Korea; however, vaccine supply is limited. Considering constraints in vaccine supply and the emergence of variant strains, we evaluated the impact of coronavirus disease (COVID-19) vaccination program in reducing incidence, ICU hospitalization, and deaths in South Korea. We developed an age-structured model of SARS-CoV-2 transmission parameterized with Korean demographics and age-specific COVID-19 outcomes. Using our model, we analyzed the impact of the COVID-19 vaccination program during the fourth wave of the pandemic in South Korea in reducing disease burden. We projected that the vaccination program can reduce the overall attack rate to 3.9% from 6.9% without vaccination, over 150 days, starting from 5 July 2021. The highest relative reduction (50%) was observed among individuals aged 50–59 years. Vaccination markedly reduced adverse outcomes, such as ICU hospitalizations and deaths, decreasing them by 45% and 43%, respectively. In the presence of the Delta variant, vaccination is expected to reduce the overall attack rate to 11.9% from 26.9%. Our results indicate that the impact of vaccination can be substantially affected by the emergence of SARS-CoV-2 variants. Furthermore, herd immunity is unlikely to be achieved with the potential emergence of the Delta variant, inconsistent with the blueprint of the South Korean government.
【저자키워드】 COVID-19, SARS-CoV-2, Vaccine, Korea, mathematical model, herd immunity, vaccine allocation strategy, 【초록키워드】 coronavirus disease, coronavirus, vaccination, pandemic, Immunity, Hospitalization, variant, severe acute respiratory syndrome Coronavirus, delta variant, adverse outcomes, ICU, outcomes, SARS-CoV-2 transmission, COVID-19 vaccination, SARS-CoV-2 variants, attack rate, herd immunity, death, incidence, respiratory, South Korea, disease, Strains, Korean, deaths, demographics, Government, reduction, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, blueprint, individual, South, Administered, highest, analyzed, affected, evaluated, unlikely, reduced, reducing, reduce, expected, 【제목키워드】 Impact, Program, Wave,