Abstract
Background: Invasive meningococcal disease (IMD) has rapid onset, high fatality, and high risk of long-term complications. Fiji Ministry of Health and Medical Services (MoHMS) recently delivered a national meningococcal C (Men C) vaccination campaign (1-19yrs) as part of its response to an outbreak of meningococcal disease declared in 2018 and are now considering introducing routine Men C vaccination to maintain protection from Men C disease. However, conjugate vaccines are expensive, particularly for countries that do not benefit from Gavi prices. At the same time, there are important health systems costs associated with responding to an outbreak.
Objectives: To evaluate the potential impact and cost-effectiveness of the following Men C vaccination strategies over the period 2018-2040 in Fij: (i) mass vaccination of all individuals aged 1-19 years in the year 2018; and (ii) mass vaccination in 2018 followed by national routine vaccination of adolescents aged 13 years every year between 2022 and 2040.
Methods: We used the UNIVAC decision-support model to evaluate the impact and cost-effectiveness of the two Men C vaccination strategies. We compared both strategies to no vaccination and to each other. We used real-world data on the cost and short-term impact of the 2018 mass campaign, and modelled alternative ‘what-if’ scenarios to assess the potential impact of the two strategies (and no vaccination) on Men C outbreaks expected to occur over the period 2018-2040. The scale and frequency of Men C outbreaks in the absence of vaccination was assumed to follow the same pattern observed in historical trends and based on population susceptibility in the absence of routine immunization. Health outcomes were measured in cases, deaths, long-term sequelae and disability-adjusted life years (DALYs). The primary outcome measure was the incremental cost-effectiveness ratio (discounted cost per DALY averted). We use a health systems perspective, including both government and donor costs, with a societal perspective undertaken in sensitivity analysis. Future costs and benefits were discounted at 3%. We ran deterministic scenario analyses to explore the impact of uncertainties in our data and assumptions.
Results: The 2018 mass vaccination campaign cost US$2.8 million. Preliminary results indicate that the 2018 mass campaign was cost-effective, with an incremental cost-effectiveness ratio (ICER) below GDP/capita (US$6,267). Routine immunisation would cost $4.4 million or $1.5 million (discounted) over 20 years, with PAHO pricing for Men C versus low-cost vaccine respectively. The number of IMD cases, deaths and DALYs averted due to routine immunisation varies depending on when a second outbreak is modelled to occur.
Conclusion: Middle-income countries face substantial challenges in introducing costly vaccines such as Men C. A cheaper pentavalent meningococcal vaccine may obtain WHO pre-qualification in the future, potentially offering protection from outbreaks at a more affordable cost. These findings will provide evidence to inform Fiji MoHMS’ decision on routine Men C vaccine introduction. Given the uncertainty in model parameters, strengthening surveillance of meningococcal disease remains critical to monitor disease incidence.