Cost-effectiveness of the second COVID-19 booster vaccination in the United States

BackgroundThe United States (US) authorized the second COVID-19 booster for individuals aged 50+ years on March 29, 2022. To date, the cost-effectiveness of the second booster strategy remains unassessed. MethodsWe developed a decision-analytic SEIR-Markov model by five age groups (0-4yrs, 5-11yrs 12-17yrs, 18-49yrs, and 50+yrs) and calibrated the model by actual mortality in each age group in the US. We conducted fives scenarios to evaluate the cost-effectiveness of the second booster strategy and incremental benefits if the strategy would expand to 18-49yrs and 12-17yrs, from a healthcare system perspective. FindingsImplementing the second booster strategy for those aged 50+yrs would cost $807 million but reduce direct medical costs by $1,128 million, corresponding to a benefit-cost ratio of 1.40. Moreover, the strategy would also result in a gain of 1,048 quality-adjusted life-years (QALYs) during the 180 days, indicating it was cost-saving. Further, vaccinating individuals aged 18-49yrs with the second booster would result in an additional gain of $1,566 million and 2,276 QALYs. Similarly, expanding vaccination to individuals aged 12-17yrs would result in an additional gain of $15 million and 89 QALYs. However, if social interaction between all age groups was severed, vaccination expansion to 18-49yrs and 12-17yrs would no longer be cost-effective. InterpretationThe second booster strategy was likely to be cost-effective in reducing the disease burden of the COVID-19 pandemic. Expanding the second booster strategy to 18-49yrs and 12-17yrs would remain cost-effective due to their social contacts with the older age group. FundingWorld Health Organization