OBJECTIVES: Evidence suggests that COVID-19 vaccines lose their effectiveness over time because of new variants and/or waning of vaccine-elicited immunity. Therefore, several countries have authorized the administration of booster doses to maintain vaccine effectiveness and prevent a rise in COVID-19 cases. In this study, we quantified the public health impact of an annual booster campaign with the mRNA-1273 bivalent vaccine in the Netherlands.

METHODS: A decision tree–based budget impact model was developed to estimate the impact of an mRNA-1273 booster vaccination programme compared with both no booster vaccination and the BNT162b2 bivalent vaccine from a healthcare system perspective over a 3-year time horizon. Two potential scenarios were considered: vaccinating all adults (≥18 years) and only those >60 years. For individuals aged ≥60 years, booster coverage was considered to be similar to previous influenza vaccination coverage in the Netherlands: 49.40% (60-65 years) and 72.60% (≥65 years). For individuals aged 18-29 years (0.30%), 30-49 years (0.40%), and 49-50 years (4.30%), coverage was assumed to be the same as coverage for the second COVID-19 booster in the Netherlands.

RESULTS: Compared with no booster vaccination, vaccination with mRNA-1273 was associated with a notable reduction in COVID-19–related infections (690,641 and 660,006), hospitalizations (97,954 and 95,795), and deaths (12,314 and 12,159) among all adults and older adults, respectively. Study results also indicated that booster vaccination with mRNA-1273 averted more infections (47,426 and 45,267), hospitalizations (3366 and 3306), and deaths (424 and 419) than booster vaccination with the BNT162b2 bivalent vaccine in the 2 vaccination scenarios, respectively, over the 3-year period considered in the analysis.