Fear of Adverse Effects and COVID-19 Vaccine Hesitancy: Recommendations of the Treatment Expectation Expert Group

The current pandemic has posed an unpresented challenge on many levels.Therefore, the development of vaccines was eagerly awaited, and the first breakthroughs were celebrated.However, it soon became clear that to end the pandemic, we would have to address another ubiquitous problem: the widespread hesitancy toward or downright rejection of vaccination.To achieve population immunity, a large majority of people has to participate.However, in a recent survey of US health care workers, 48% had not yet been vaccinated, and of those, 18% did not plan on receiving a COVID-19 vaccine because of concerns over adverse effects and the vaccines' newness.Health care decisions, including whether to take part in vaccination against COVID-19, are based on the comparison of the potential costs of participation with the expected benefits.Costs can span a variety of factors, but fear of adverse effects has featured prominently in recent surveys.As extensive research of our groups and others on nocebo effects has shown, 1 it is-ironically-this very same fear that can amplify and even induce adverse effects.Therefore, addressing concerns by providing evidence-based information as part of larger information campaigns and individual conversations is key to increasing vaccine uptake.We present a number of strategies that can be adopted to target a fear of adverse effects. Providing Accurate Information About Vaccination Adverse EffectsAcknowledging that vaccines can cause unwanted effects and that concerns about adverse effects are understandable is an important first step in any conversation about concerns.This is particularly relevant for those who have experienced adverse effects in the past or are more likely to be affected.However, it is also worth pointing out that most people experience no or only mild adverse effects.It is also important to explain that not all symptoms that occur following vaccination are caused by the vaccine.In fact, the major trial investigating the Pfizer-BioNTech vaccine, which included more than 40 000 people, reported fatigue rates after the first shot in the placebo group of 23% to 33%, headache rates of 18% to 34%, and muscle pain rates of 8% to 11%. 2 Easy access to medical advice when adverse effects occur is pivotal to build trust and address concerns before they trigger a level of fear that amplifies the negative experience. Positive Framing of Mild Adverse EffectsLegal regulations demand full transparency about potential side effects.However, the way this information is presented strongly influences decision-making and perceptions of symptoms.Instead of stating the probability of experiencing a particular adverse effect, we can provide the probability of not experiencing this effect.Moreover, instead of offering a noncurated list of all possible adverse effects without an estimate of their likelihood to occur, we can provide more graduated information about the likelihood of experiencing an adverse effect (eg, from very common to very rare).Lastly, while severe adverse effects are of course a matter of concern and need to be monitored closely, mild forms of fever, muscle pain, or fatigue also indicate that the immune system is responding appropriately to the vaccine.Pointing out the healthy nature of reactogenicity can help the individual