Mapping inequities in global vaccine sentiment research.

introductionNegative public sentiment towards vaccination (PSV) poses significant challenges to the effectiveness of immunisation programmes, with dramatic effects on morbidity and mortality for vaccine-preventable diseases. Yet, health research is often shaped by economic and geopolitical factors rather than countries' epidemiological or healthcare needs. This study examines global patterns and drivers of PSV research on five vaccines-polio, measles, human papillomavirus, influenza and SARS-CoV-2-and evaluates the COVID-19 pandemic's impact on research volume, focus and distribution.

methodsWe conducted a machine-learning-assisted literature search on PSV without geographical, language or time constraints. Using natural language processing, network and statistical analyses, we examined the global PSV research landscape and identified geographical, epidemiological and economic drivers.

resultsWe analysed 13 287 articles and detected consistent literature growth from 1980 onwards, with vaccine-specific peaks following key licensing events. After 2020, publication volumes rose above projections for influenza (32%; 95% CI 20% to 46%) but declined for polio (-56%; 95% CI -68% to -26%) and measles (-17%; 95% CI -33% to 9%). Although PSV research had global coverage, its distribution was markedly imbalanced, largely shaped by country-specific economic factors. A few high-income countries (HICs) produced 72% of publications and the likelihood of a country being studied varied by income and vaccine. Foreign authorship also increased as the income of the studied country decreased (over 75% in low-income and middle-income countries vs below 50% in HIC).

conclusionsPSV research reveals persistent inequities, with a misalignment between countries leading research and populations most in need of its outcomes. These inequities, further exacerbated by COVID-19 disruptions, reflect systematic imbalances in global health. Our findings underscore the need to decolonise research by fostering leadership, agenda-setting and accountability that centre on the necessities of affected communities. Achieving this will require funding and publication reforms that promote equitable collaborations and elevate local priorities alongside long-standing global health objectives.