Examining epidemiological models and economic analyses of typhoid conjugate vaccine: A scoping review

This peer-reviewed article presents a scoping review of epidemiological models and economic analyses related to typhoid conjugate vaccine (TCV). Using the Arksey and O’Malley framework and searching five databases, the study mapped evidence on the cost of illness of typhoid, cost of vaccination and delivery, public health impact, and cost-effectiveness of TCV across 26 studies. 

Key findings 

• The review included 26 studies published between 1998 and 2024, covering Sub-Saharan Africa, South and East Asia, the Pacific, Latin America, the Middle East, and Europe.
• Ten studies on typhoid cost of illness found that inpatient treatment costs were higher than outpatient costs, and indirect costs from lost income were substantial, especially for hospitalized patients.
• Five studies on vaccination costs found that campaign delivery generally cost more than routine delivery, and economic costs consistently exceeded financial costs when opportunity costs and donated inputs were included.
• Two public health impact studies using dynamic transmission models projected case reductions ranging from 2% to 94% and mortality reductions of up to 36% or 100%, depending on the vaccination strategy.
• Nine economic evaluations found that TCV was generally more cost-effective in high-incidence and urban settings, with some strategies reported as cost-saving.
• Studies combining routine vaccination with catch-up campaigns were often more cost-effective than routine-only strategies, though the optimal approach depended on local incidence, costs, and modelling assumptions.
• The review identifies important evidence gaps, particularly around herd immunity, antimicrobial resistance, long-term impact, and the need for more local cost data.

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