  Vaccination programs may help the world to reduce or eliminate Covid-19.
Information about them may help countries to design theirs more effectively,
with important benefits for public health. This article investigates whether it
is possible to get insights into national vaccination programmes from a quick
international comparison of public comments on Twitter. For this, word
association thematic analysis (WATA) was applied to English-language
vaccine-related tweets from eight countries gathered between 5 December 2020
and 21 March 2021. The method was able to quickly identify multiple
international differences. Whilst some were irrelevant, potentially non-trivial
differences include differing extents to which non-government scientific
experts are important to national vaccination discussions. For example, Ireland
seemed to be the only country in which university presidents were widely
tweeted about in vaccine discussions. India's vaccine kindness term
#VaccineMaitri was another interesting difference, highlighting the need for
international sharing.
