‘It's a shot, not a vaccine like MMR’: A new type of vaccine-specific scepticism on Twitter/X during the COVID-19 pandemic

Background

While it is well-known that vaccine hesitancy can be vaccine-specific, little is known about how people spontaneously evaluate different vaccines in comparison with one another, or the implications of such comparisons for vaccine attitudes. This paper first investigates how people posting on Twitter/X in 2020–2022 discussed the MMR vaccine and the COVID-19 vaccines in relation to each other. Next it reveals a new manifestation of vaccine scepticism, namely the claim that some vaccines, notably those against COVID-19, are in fact not vaccines.

Methods

A 9-million-word ‘corpus’ was created, consisting of tweets containing references to the MMR vaccine posted in 2008–2022. First, tweets posted in 2020–2022 and also containing references to COVID-19 were coded for: (1) vaccine-specific evaluation, and (2) vaccine-related topic. Then, the whole corpus was analysed for tweets that contain expressions that challenge the status of a vaccine as a vaccine (e.g. ‘not a vaccine’, and the use of ‘shot’ in contrast with ‘vaccine’).

Results

In 2020–2022, tweets mentioning COVID-19 alongside MMR show an increasing tendency to compare the COVID-19 vaccines unfavourably with MMR, based on perceived low effectiveness against infection. A further analysis of the whole corpus reveals:

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  A tendency in 2020–2022 to challenge the status of COVID-19 vaccines, as well as flu vaccines, as vaccines;
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  A perceived contrast in 2020–2022 between ‘shot’ and ‘vaccine’, with the former being described as an inferior medical intervention.
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  Very little evidence of similar arguments being made about any vaccines in 2008–2019.

Conclusion

Data from Twitter/X suggests that perceptions about low effectiveness of the COVID-19 vaccines against infection have led to a belief that they are inferior to MMR and other vaccines, or are not vaccines at all. It is important to address this new form of scepticism about vaccines that primarily prevent serious illness.