It Is Crucial to Talk Openly About Vaccine Side Effects if We Are to Defeat the COVID Pandemic

“Failure to communicate about vaccines creates uncertainty and people feel misled,” said Michael Bang Petersen, professor of political science at Aarhus BSS, University of Aarhus. Credit: University of Aarhus

New research from Aarhus BSS at Aarhus University shows that openness about the effectiveness and side effects of vaccines builds trust in health authorities, and this is a crucial factor if we are to beat the coronavirus pandemic.

Concerns have been raised about the AstraZeneca and Johnson & Johnson vaccines regarding very rare but potentially fatal side effects associated with low platelet counts and blood clots. Recently, reports also surfaced that the Pfizer-BioNTech vaccine can cause a rare but serious side effect: heart inflammation. Concerns about side effects may lead to vaccine hesitancy, which the WHO considers one of the “ten threats to global health.” Ensuring adequate vaccine adoption is a key challenge in beating the coronavirus pandemic, both now and in the future.

How can health authorities and politicians contribute to the public acceptance of vaccines, which – aside from their rare side effects – have proven effective in preventing serious Covid-19 disease? The best way to do this is to talk openly about all aspects of the vaccines, including possible negative aspects such as side effects.

“How to communicate about the vaccines is a real dilemma. Politicians want to stop the pandemic as soon as possible, and this could give them an incentive to mitigate the negative sides of the vaccines to vaccinate as many people as possible,” said Michael Bang Petersen, professor of political science at Aarhus BSS, University of Aarhus.

“But our research shows that it does not promote support for vaccination if the communication about the vaccines is reassuring, but vague. On the contrary, vague communication weakens people’s trust in health authorities and fuels conspiracy theories. When communication is not transparent, it leads to uncertainty and people feel misled,” says Michael Bang Petersen.

Together with colleagues from Aarhus BSS of the University of Aarhus, he studied the effect of different ways of communicating about vaccines. The study involved 13,000 participants, half Americans and half Danes, and the results have just been published in the widely recognized journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Vague communication fuels conspiracies

The results of the study show that open communication promotes support for the vaccines when it transparently describes neutral and positive facts about the vaccines. However, the willingness to be vaccinated decreases when communication about negative properties of the vaccine is open.

“Transparency about the negative properties of a vaccine causes hesitation. But this hesitation is based on reasons, which is why health authorities still have the opportunity to communicate with citizens and explain to them why it may still be advisable to accept the vaccine,” said Michael Bang Petersen.

On the other hand, vague or reassuring communication, in which negative characteristics of the vaccines are toned down, lowers vaccine acceptance. The reason is that vague communication creates a feeling of hesitation and uncertainty, and this in turn fuels conspiracy theories and diminishes trust in health authorities.

Trust is essential

The advantage of open communication – including on the negative sides – is that it prevents conspiracy theories from spreading while increasing trust in health authorities. According to the researchers, this is the key to beating the coronavirus pandemic.

“Maintaining trust in health authorities is extremely important as it is the most critical factor in gaining public support for the vaccines. Communicating transparently about vaccines is the single most important factor in sustaining vaccine adoption,” said Michael Bang Petersen, continuing:

“Openness builds long-term confidence, and this is crucial if we need to be revaccinated, or in connection with the next major health crisis.”

Reference: “Transparent communication about negative characteristics of COVID-19 vaccines reduces adoption but increases confidence” by Michael Bang Petersen, Alexander Bor, Frederik Jørgensen, and Marie Fly Lindholt, July 2, 2021, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2024597118

Facts about the study:

The new findings are part of a large-scale data-driven research project titled HOPE – How Democracies Cope with COVID-19. The project is funded by the Carlsberg Foundation and led by Professor Michael Bang Petersen. METHODS: Pre-registered experimental studies with a total of more than 13,000 participants, half of whom were Danes and half were Americans. The research is published in the article “Transparent Communication on Negative Features of COVID-19 Vaccines Reduces Acceptance but Increases Trust” in Proceedings of the National Academy of Sciences of the United States of America (PNAS). Authors: Professor Michael Bang Petersen, Postdoc Alexander Bor, Postdoc Frederik Jørgensen and Research Assistant Marie Fly Lindholt from the Department of Political Science of Aarhus BSS, University of Aarhus