Introducing Rotavirus Vaccination in Nigeria: Economic Evaluation and Implications.

BACKGROUND: As Nigeria prepares to introduce a rotavirus vaccine, the Gavi board has approved the extension of the transition period for the country until 2028. The current position of the country on Gavi's funding profile calls for a pragmatic step in planning and implementation so that sustainability at the fully self-financing phase will be feasible. OBJECTIVE: This study aimed to inform the decisions of the country's health policymakers on the costs, benefits, and implications of the introduction of rotavirus vaccine. METHODS: This study was an economic evaluation using a simulation-based Markov model. It compared four approaches: 'no vaccination' and vaccination with ROTARIX, ROTAVAC, or ROTASIIL. Ten cohorts from the year 2021 to 2030 were used in the analysis. Primary measures were the benefit-cost ratio (BCR) and the incremental cost-effectiveness ratio (ICER). Future costs and outcomes were discounted to 2019 values. RESULTS: The adjusted vaccine cost of ROTARIX was the highest, followed by ROTAVAC and ROTASIIL, whereas the immunization delivery cost was in the reverse order. All the vaccines were very cost effective, with ROTARIX being the optimal choice for the 10-year period, having a BCR of 27 and an ICER of $US100 (95% confidence interval [CI] 71-130)/disability-adjusted life-year averted. Adopting ROTARIX was the optimal choice from 2021 to 2027, whereas ROTAVAC was optimal from 2028 to 2030. The net budget impact of the programme was $US76.9 million for the 10-year period. The opportunity cost of a late introduction was about $US8 million per annum from 2021 to 2028. CONCLUSIONS: The rotavirus vaccine ROTARIX should be implemented in Nigeria at the earliest opportunity. A switch to ROTAVAC should be considered from the year 2028. Cost-minimization measures are imperative to ensure the sustainability of the programme after the transition out of Gavi support.