Vaccine security and self-sufficiency have received increased global attention in the wake of the COVID-19 pandemic, as low- and middle-income countries were heavily dependent on high-income countries (HICs) and international organizations for vaccine supply, resulting in global competition for vaccines and huge inequities. Achieving vaccine security and self-sufficiency is of high importance to Southeast Asia. To achieve this goal, the Association of Southeast Asian Nations (ASEAN) established the ASEAN vaccine security and self-reliance (AVSSR) initiative. Building on the efforts of ASEAN leadership, the World Bank commissioned this study to estimate the public health and economic benefits arising from investments in AVSSR, specifically in vaccine research and development (R&D), manufacturing, and regulation. The study assumes that five ASEAN countries - Indonesia, Malaysia, the Philippines, Thailand, and Vietnam - make public and private investments to strengthen vaccine security. Applying a societal perspective, the study considers four different investments scenarios. Scenario 1 assumes that costs will be shared between these five countries and that these countries alone will benefit from the vaccine security efforts, while Scenario 2 assumes health and economic benefits to the other five ASEAN countries (Brunei, Cambodia, Laos, Myanmar, and Singapore) as well. Scenario 3 assumes that only one country of 100 million people produces and prioritizes vaccines for its population, while Scenario 4 assumes a pandemic of COVID19 magnitude. The findings of the study clearly show that regional investments in clinical trials, manufacturing and regulatory capacity building will have a substantial public health impact and offer high benefit-cost ratios. Findings from this study align with the AVSSR Strategic and Action Plan 2021-2025, which makes the case for stronger regional vaccine capacity, enhanced vaccine manufacturing capacity, and human resource development to realize the goal of self-reliance
