Abstract Introduction. Social listening programmes across digital channels are increasingly becoming an integral part of health preparedness and response planning. To best support communication and programmatic strategies, it is essential to adopt a social listening approach that balances cross-sectional in-depth analysis of the ongoing online conversation to identify key concerns, information voids and misinformation, with a longitudinal view of how discourse evolves over time and how topics recur or emerge. This study analyses online conversations about COVID-19 vaccines in Eastern and Southern Africa, using a taxonomy developed and refined in collaboration with social and behaviour change teams working in the field to increase vaccine acceptance and uptake. Methodology. The COVID-19 vaccine taxonomy was developed and applied to filter online conversations tracked into nine subtopic categories. The taxonomy has been used and its search strings refined on a weekly basis to provide analysis and recommendations for vaccine acceptance and uptake. In this analysis, the taxonomy is applied on longitudinal data of conversations about COVID-19 vaccines in 21 countries in Eastern and Southern Africa over the period December 1, 2020 - December 31, 2021. Metrics included in the analysis included volume of posts or articles and related user engagement. Qualitative analysis of content was conducted to identify key concerns, information voids and misinformation. Results. Over 300,000 articles and posts about COVID-19 vaccines shared by users or outlets geolocated in the region were analysed. These results generated over 14 million engagements on social media and digital platforms. The analysis shows how conversations about access and availability of vaccines have represented the largest share of engagement over the course of the period. Conversations about vaccine effectiveness and safety represented the second and third largest share of engagement, with peaks observed in August and November 2021. Online interest in childhood vaccination increased over time as vaccine eligibility criteria expanded in some countries in the region. Conversations mentioning mandates and certificates peaked in the last quarter of 2021 as governments and private sector entities expanded vaccine requirements. Conclusions. Findings from this study show the importance of monitoring conversation trends over time and adjust the analysis to include emerging topics. The analysis also points to the need to consider concerns, information voids and misinformation around effectiveness and safety of vaccines in the context of overall concern for vaccine availability and access in Eastern and Southern Africa. This is fundamental to inform social and behaviour change strategies that promote vaccine demand effectively, without increasing public frustration over vaccine availability challenges and downplaying concerns for vaccine equity. https://www.varnconference.org/wp-content/uploads/2022/02/Silvia-Sommariva-Social-listening_VARN_Conference-FINAL.pdf

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