By IDSE News Staff
Strategies that frame the risk for COVID-19 vaccination side effects in the context of other risks can increase people's intention to get the vaccine, a study shows (eLife 2022 Aug 16. doi:10.7554/eLife.78765).
The research could help inform public health campaigns aimed at increasing the uptake of COVID-19 boosters, which are currently far below target levels.
The study was conducted in the United States and the United Kingdom, where vaccination rates have slowed, and only 63.9% and 71.3% of the respective populations are fully vaccinated. Moreover, just more than 27% and 55% of adults have received their booster vaccines in the United States and the United Kingdom, respectively.
“Vaccine hesitancy is not the result of a single common cause and can vary for different people and populations,” explained lead author Nikkil Sudharsanan, PhD, an assistant professor of behavioral science for Disease Prevention and Health Care, Technical University of Munich. “A common fear around COVID-19 vaccination is concern about side effects, heightened by widespread media coverage that did not put the very low risk of side effects in context with other risks, such as the likelihood of death from COVID-19 itself. Addressing these public concerns will be a key component of efforts to improve vaccine use in the U.S., U.K. and globally, especially with recommendations for ongoing booster doses.”
Evidence shows that the way risks are framed and presented to people can affect their perceptions of the severity of risk and, ultimately, their behavior. The researchers set out to compare different ways of framing risk for a hypothetical COVID-19 vaccine, then asked participants whether they would get the vaccine and how safe they thought it was.
They designed an online randomized controlled trial, providing vaccine information to 8,988 people who were at least 18 years of age in both countries. Participants were presented with information about the hypothetical vaccine, including the risk for serious blood clots, framed in three different ways:
- with an additional label explaining whether the risk is low or high,
- adding a comparison risk, such as the risk for dying in a motor vehicle accident, and
- whether risks were communicated as absolute (presenting the actual vaccine side effect risk next to other common risks) or relative (presenting the vaccine side effect risk as a multiple of other common risks).
The findings showed that adding a simple qualitative risk level of “very low risk” next to the vaccination side effect increased people's intentions to get the vaccine by 3%. Similarly, adding a comparison with motor vehicle accident death rates increased intentions by 2.4%. These framing tools worked even better when used together, increasing intentions to vaccinate by 6.1%.
The researchers also reported some surprising results: comparing vaccination side effect rates with COVID-19 death rates did not appear to influence intentions to vaccinate. This finding was unexpected because COVID-19 death rates are substantially higher than motor vehicle accident death rates (U.S., 170 per 100,000 versus 12 per 100,000), and it is a cause of death directly associated with the purpose of COVID-19 vaccination strategies.
A second surprise was that expressing risk as relative versus absolute had no apparent effect on people's willingness to get the hypothetical vaccine.
“We believe our results can inform communication efforts aimed at increasing vaccination, especially booster vaccinations,” said co-author Alain Vandormael, PhD, MS, a senior data scientist at the Heidelberg Institute of Global Health, Heidelberg University Hospital, in Germany. “Our results are focused on vaccine intentions and not vaccination rates, so the next step is to test whether these framing efforts can increase shots in arms before translating our findings into policy action.”
