Impact of the first booster vaccine against SARS-CoV-2 in Chile

The present paper proposes a novel methodology for evaluating the impact of a vaccination plan against a transmissible disease. The methodology has two distinct stages. The initial stage comprises a compartmental model that describes the transmission of the disease within the population. This model is composed of fundamental parts representing the vaccination status and is used in this initial stage to estimate the number of cases and deaths averted by the vaccination plan. The case dynamics generated by the compartmental model serve as the input for a data-driven model in the second part of the methodology. The second model is statistical in nature and provides additional information regarding the number of hospitalizations and ICU admissions averted. This methodology is applied to assess the impact of booster SARS-CoV-2 vaccines in Chile, resulting in an estimation of 84 % (95 % confidence interval (CI): 74 %-92 %) of cases, 73 % (95 % CI: 57 %, 80 %) of hospital admissions, 77 % (95 % CI: 61 %, 84 %) of intensive care unit admissions, and 78 % (95 % CI: 62 %-85 %) of deaths averted between August 16 and December 31, 2021.