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In countries with lower-than-expected COVID-19 vaccination rates, mentions of side effects and negative sentiments on COVID-19 vaccines dominate overall social media discourse, according to our new research published in the journal Vaccines.
Our team wanted to understand whether the tone of social media conversations around the world matched individual country-level vaccination rates. To do this, we analyzed more than 21.3 million tweets in 33 languages from 192 countries posted between November 2020 and August 2021, including “COVID-19” and any mention of “vaccine” or “vaccination”. The tweet was also searched. We then calculated the percentage of these tweets that mentioned keywords indicating adverse vaccination events, such as side effects, blood clots or death.
In addition, we used an artificial intelligence algorithm to analyze the sentiment and emotional tone of the tweets. This algorithm can identify positive and negative emotions as well as emotions in language – such as happiness, fear, sadness or anger. We applied the algorithm to tweets mentioning COVID-19 vaccines, allowing us to measure general sentiment trends across different countries on Twitter.
Earlier research has shown that feelings toward vaccines can influence whether a person decides to receive a COVID-19 vaccination. Our study allowed us to examine this theory on a national scale.
Globally, 1.15% of tweets related to COVID-19 vaccines mentioned side effects. Sentiments towards vaccines were on average more negative than positive, with almost twice as many negative tweets as positive ones. But interestingly, negative emotions such as fear, sadness or anger appeared to be only 0.7 times more likely than happiness worldwide. Using these numbers as a baseline, our analysis controlled for national socioeconomic characteristics as well as the number of COVID-19 cases and deaths, and then compared countries’ Twitter trends and vaccination rates to the global average. We removed ads and spam from our analysis, but did not remove tweets that may have been posted by bots, as they are a part of the Twitter landscape.
We found that when social media discussions on vaccination are more negative in a country than the global average, vaccination rates tend to be lower than expected.
Specifically, a higher prevalence of tweets that mentioned “side effects” or displayed fear, sadness or anger was predictive of lower vaccination rates. For example, “side effects” were mentioned in 1.42% of South African tweets – higher than the global average of 1.15% – and negative sentiment appeared in tweets 1.55 times as happy – more than twice the global average. At the time of our analysis, South Africa reported a vaccination rate of 30%, which is lower than other countries with similar characteristics.
We found a similar association between negative Twitter sentiment and lower-than-expected vaccination rates in several other countries, including Namibia, Ukraine, Croatia, Poland, Mexico, the Philippines and Burma.
In the US, fear, sadness or anger appeared almost as often as happiness – showing more negativity than the global average. At the time of analysis, the vaccination rate in the US was 72%, up from 80% or higher in many other high-income countries such as Germany and Canada.
why it matters
In most developed countries – including the US – many individuals are denied vaccines, even though vaccines are plentiful and readily available.
Social media has been an important tool for dissemination of COVID-19 information. But Twitter, Facebook and other platforms have also been flooded with misinformation and misinformation as well as people’s personal sentiments on vaccination – since the start of the pandemic. Research shows that the more information people are exposed to about COVID-19 through social media, the lower their knowledge of COVID-19.
Our research expands on these individual-level findings and shows that social media discourse is also associated with vaccination behavior at the national level.
what is not yet known
Our findings show an association between social media discourse and vaccination, but this type of analysis cannot identify causality. We also did not explore the reasons behind why some countries show more negative sentiment in tweets than others. This can be linked to cultural differences between countries.
Another limitation is due to the ambiguity of the language. The AI system we used is relatively good at portraying emotions and feelings in a tweet, but not 100% accurate. Additionally, AI is not as strong when analyzing tweets in languages other than English.
what will happen next
The World Health Organization has declared widespread misinformation about COVID-19 an infodemic, and 132 countries have agreed to combat it. Our findings support the idea that global efforts to combat misinformation, address negative sentiment, and promote positive language around COVID-19 vaccination on social media can help boost global vaccination rates.