Effects of side-effect risk framing strategies on COVID-19 vaccine intentions: a randomized controlled trial

Abstract

Background:Fear over side-effects is one of the main drivers of COVID-19 vaccine hesitancy. A large literature in the behavioral and communication sciences finds that how risks are framed and presented to individuals affects their judgments of its severity. However, it remains unknown whether such framing changes can affect COVID-19 vaccine behavior and be deployed as policy solutions to reduce hesitancy.Methods:We conducted a pre-registered randomized controlled trial among 8998 participants in the United States and the United Kingdom to examine the effects of different ways of framing and presenting vaccine side-effects on individuals’ willingness to get vaccinated and their perceptions of vaccine safety.Results:Adding a descriptive risk label (‘very low risk’) next to the numerical side-effect and providing a comparison to motor-vehicle mortality increased participants’ willingness to take the COVID-19 vaccine by 3.0 percentage points (p=0.003) and 2.4 percentage points (p=0.049), respectively. These effects were independent and additive and combining both framing strategies increased willingness to receive the vaccine by 6.1 percentage points (p<0.001). Mechanistically, we find evidence that these framing effects operate by increasing individuals’ perceptions of how safe the vaccine is.Conclusions:Low-cost side-effect framing strategies can meaningfully affect vaccine intentions at a population level.Funding:Heidelberg Institute of Global Health.Clinical trial number:German Clinical Trials Registry (#DRKS00025551).

Understanding COVID-19 vaccine hesitancy: A cross-sectional study in Malang District, Indonesia

“…Earlier research highlights the impact of both factors on vaccine hesitancy. For example, prior studies have found that, rather than actual vaccine side effects, fear of side effects is one of the main reasons for which individuals refuse to be vaccinated ( 32 ). In a randomized control trial study, Sudharsanan et al found that although COVID-19 vaccine serious side effects are rare, the media's presentation of these risks may amplify concerns.…”

“…People with less education have a lower acceptance rate ( 37 ). Lower parental educational level is also a predictor of refusal of COVID-19 vaccine uptake among children ( 32 ).…”

I want to be safe: understanding the main drivers behind vaccination choice throughout the pandemic

“…Given that the number of infected individuals did not substantially decrease over time, despite a gradual increase in the number of vaccinated people, we expected a decline in the vaccine’s perceived efficacy over time while anticipating an increase in safety perception. Additionally, drawing upon the principles of prospect theory [ 41 ], wherein the fear of facing adverse side effects may be a more compelling motivation than the achievement of global immunity, we hypothesized that messages highlighting the absence of risks would result in a greater willingness to receive the fourth dose compared to messages emphasizing vaccination benefits [ 69 ]. As vaccine effectiveness perception declined, we also expected a decrease in COVID-19-related concerns but an increase in perceived social pressure.…”

The impact of side effect framing on COVID-19 booster vaccine intentions in an Australian sample

“…Information framing has been suggested as such an intervention, including by peak international bodies such as the World Health Organization (WHO) [6] . Several studies have investigated the effect of message framing on COVID-19 vaccine intention, with varied results [7] , [8] , [9] , [10] , [11] , [12] . However, with the exception of our own research [13] , none have focused on attribute framing [14] of side effect information for actual COVID-19 vaccines.…”