A bi‐objective optimization model to plan vaccination campaigns aided by temporary centers

Vaccination campaigns have saved thousands of lives and reached even the world's most remote areas. However, the COVID‐19 pandemic significantly changed the strategies for such campaigns. It is now crucial to rigorously consider new factors when planning the operational aspects of these campaigns, particularly for last‐mile vaccine dispensing. First, a large share of the population must be vaccinated, with emphasis on vulnerable groups at higher risk. Second, if the virus is highly contagious and capable of asymptomatic transmission, implementing public health measures at vaccination sites becomes paramount. To address these challenges, we propose a bi‐objective optimization model to support healthcare decision‐making. It defines a schedule for locating temporary vaccination centers and assigning populations to permanent and temporary sites over a planning horizon. Moreover, we formalize and validate a minimum set of properties for a function‐based prioritization mechanism to ensure consistent prioritization. One objective prioritizes vaccinating vulnerable groups according to our novel function‐based approach, while the other minimizes the operational costs of temporary centers. In the complex environment of a pandemic, the strategic integration and use of temporary and permanent vaccination centers is vital for creating a robust and responsive vaccination strategy. Temporary centers, whose locations are determined by the model, improve access for hard‐to‐reach groups, contribute to minimizing crowding at permanent sites, and lower infection risks. Our results, demonstrated through a case study, show that the model effectively allocates resources and generates various vaccination plans that cater to different priority levels assigned to each objective, thereby offering valuable decision support.