Modeling the Potential Public Health Impact of Updated COVID-19 Vaccination Strategies in Singapore: Epidemiological...

This study estimated the potential public health impact of alternative COVID-19 vaccination strategies in Singapore.

The outcomes of alternative vaccination strategies using a Pfizer-BioNTech COVID-19 vaccine updated to the latest circulating strain were estimated using a combined decision tree-Markov cohort model. The model was previously used to estimate the impact of vaccination based on epidemiological data from 2021/22 and vaccine coverage data from 2022/23. It has now been updated with epidemiology data from 2023/24 and an assumed vaccine coverage of 20%. Age-specific inputs were derived from local epidemiological data and published sources. The model projected health outcomes (cases, hospitalizations, and deaths) and economic outcomes (direct medical costs and productivity losses) across different age and risk subgroups.

Vaccinating individuals aged 60 and above, as well as individuals aged 6 months to 59 years with comorbidities, making them at high risk for severe COVID-19 outcomes, with a vaccine coverage of 20%, is projected to result in 14,099 fewer infections, 2668 fewer hospitalizations, and 21 fewer deaths in 1 year. This leads to a total estimated savings of SGD 21.3 million in direct medical costs and SGD 24.8 million in indirect costs. Increasing coverage to 50% has the potential to further increase deaths, hospitalizations, infections, and costs averted by 150%.

Although vaccination has a smaller impact on public health compared to the previous evaluation because of the updated epidemiology and lower estimated coverage, an updated vaccine can still have a public health and economic impact in Singapore.