New findings show the potential for language to enhance trust in COVID-19 vaccines

A simple language intervention has the potential to boost COVID-19 vaccination rates, by strengthening trust in the vaccines, researchers say.

A study published this month in the journal Nature Scientific found that people from bilingual communities in Hong Kong were more likely to agree to having the COVID-19 vaccine after being given information in English, than after receiving it in Cantonese.

Researchers say their findings show the potential for language to enhance trust in vaccines worldwide.

Our ultimate goal with this study was to find a low-cost intervention, which might have potential to increase trust associated with the COVID-19 vaccine and through this reduce vaccine hesitancy."

Janet Geipel, Study Lead Author, Psychologist and Assistant Professor, University of Exeter Business School

The researchers sampled 611 unvaccinated Chinese people living in Hong Kong, who were divided into two groups and given the exact same COVID-19 vaccine information either in English or Cantonese — the two languages predominant in the region.

Participants who read materials about the vaccine in English were seven per cent more likely to say "yes" to having the COVID-19 vaccine and seven per cent less likely to be "unsure" about having the vaccine.

The percentage of people saying "no" to the vaccine was about the same in both groups.

Co-author Boaz Keysar, a psychology professor at the University of Chicago, in the US, said: "Seven percentage points might not sound like much, but it is actually huge in the context of interventions … Seven per cent of 10 million people, for example is a lot of people."

According to the researchers, the context in which two different languages are used, and the associations people have with those languages, vary from place to place. Where one language is associated with more public trust than the other, that language should be used to communicate vaccine and other health information, they suggest.

"The finding that language can influence public trust in COVID-19 vaccines might be interesting for public health policymakers, especially in countries with bilingual populations," added Geipel.

With more than half the global population using two or more languages in everyday life, she believes language interventions are a practical solution if the local context is properly considered.

Lennah Kinyanjui is a project manager for the COVID-19 response project at Amref Health Africa and has worked with communities in Kenya where Swahili and a local language are spoken. She said: "People trust information from their local leaders and peers, delivered in local languages.

"Radio messages and radio talk shows in local languages have had greater impact, clarifying myths and misconceptions that have hindered vaccine uptake."

Education is also an important factor, Kinyanjui believes. "People who are illiterate or semi-illiterate respond better to one language, specifically, the local language," she said.

"However, the literate trust information more if they see the same information from different sources and in different languages."

The researchers behind the Hong Kong study say their findings should be considered not just as a case study, but as a demonstration of the power of language to enhance trust generally.

Beyond vaccines, language choice could be taken into consideration around the world to provide health information in a variety of contexts, the authors propose, citing cancer screening as an example.