Presentation (CTI)

OBJECTIVES: Whole-cell pertussis (wP) containing vaccines are currently implemented in many National Immunization Programmes (NIPs) for vaccination of infants from 6 weeks of age through school-entry boosters (4-6 years). Switching to acellular pertussis (aP) hexavalent vaccines for primary series incurs higher acquisition costs but offers lower reactogenicity and a simplified 6-in-1 formulation, decreasing adverse event (AE) management, programmatic, and productivity costs - hidden costs critical to assessing the true immunization program costs. Limited data exist on the magnitude of these hidden costs and their economic impact. This targeted literature review summarizes available health economic evidence on total costs of immunization programs associated with aP hexavalent vaccine vs wP-containing vaccine implementation to inform NIP decision-making.
METHODS: A targeted literature search was conducted in Embase and MEDLINE (via Ovid) from inception to December 2025 using predefined keywords. Cost-minimization analyses and budget impact analyses from payer and societal perspectives were included. Primary outcomes of interest were direct medical costs (vaccine acquisition, adverse event management, logistics, and administration), direct non-medical costs (transportation), and indirect costs (productivity losses).
RESULTS: Ten health economic studies across 10 countries from North Africa, Latin America, Asia-Pacific, and Europe were identified and considered. Switching to aP hexavalent vaccine offset a significant proportion of vaccine acquisition costs, with hidden cost reductions of 50-61% from both payer and societal perspectives. Reductions varied substantially across cost categories: AE management costs decreased by 33-75%, logistical and programmatic costs decreased by 15-80%, and productivity losses decreased by 31-99%. Net budget impact after accounting for hidden cost offsets ranged from 4-56%, with several studies demonstrating cost savings when indirect costs were included.
CONCLUSIONS: Switching from current wP-based vaccination programmes to aP hexavalent vaccine demonstrated substantial hidden cost reductions that offset higher acquisition costs, supporting economic viability for NIPs across healthcare systems.