Optimising the introduction of multiple childhood vaccines in Japan: A model proposing the introduction sequence achieving the highest health gains.

BACKGROUND: Many countries struggle with the prioritisation of introducing new vaccines because of budget limitations and lack of focus on public health goals. A model has been developed that defines how specific health goals can be optimised through immunisation within vaccination budget constraints.

METHODS: Japan, as a country example, could introduce 4 new pediatric vaccines targeting influenza, rotavirus, pneumococcal disease and mumps with known burden of disease, vaccine efficacies and maximum achievable coverages. Operating under budget constraints, the Portfolio-model for the Management of Vaccines (PMV) identifies the optimal vaccine ranking and combination for achieving the maximum QALY gain over a period of 10 calendar years in children <5 years old. This vaccine strategy, of interest and helpful for a healthcare decision maker, is compared with an unranked vaccine selection process.

RESULTS: Results indicate that the maximum QALY gain with a fixed annual vaccination budget of 500 billion Japanese Yen over a 10-year period is 72,288 QALYs using the optimal sequence of vaccine introduction (mumps [1st], followed by influenza [2nd], rotavirus [3rd], and pneumococcal [4th]). With exactly the same budget but without vaccine ranking, the total QALY gain can be 20% lower.

CONCLUSION: The PMV model could be a helpful tool for decision makers in those environments with limited budget where vaccines have to be selected for trying to optimise specific health goals.