  COVID-19 pandemic has brought unprecedented challenges to the world, and
vaccination has been a key strategy to combat the disease. Since Twitter is one
of the most widely used public microblogging platforms, researchers have
analysed COVID-19 vaccines and vaccination Twitter discourse to explore the
conversational dynamics around the topic. While contributing to the crisis
informatics literature, we curate a large-scale geotagged Twitter dataset,
GeoCovaxTweets Extended, and explore the discourse through multiple
spatiotemporal analyses. This dataset covers a longer time span of 38 months,
from the announcement of the first vaccine to the availability of booster
doses. Results show that 43.4% of the collected tweets, although containing
phrases and keywords related to vaccines and vaccinations, were unrelated to
the COVID-19 context. In total, 23.1% of the discussions on vaccines and
vaccinations were classified as Pro, 16% as Hesitant, 11.4% as Anti, and 6.1%
as Informative. The trend shifted towards Pro and Informative tweets globally
as vaccination programs progressed, indicating a change in the public's
perception of COVID-19 vaccines and vaccination. Furthermore, we explored the
discourse based on account attributes, i.e., followers counts and tweet counts.
Results show a significant pattern of discourse differences. Our findings
highlight the potential of harnessing a large-scale geotagged Twitter dataset
to understand global public health communication and to inform targeted
interventions aimed at addressing vaccine hesitancy.
