Failing to communicate COVID-19 vaccine uncertainties has negative consequences

In a pandemic, uncertainty is salient, especially concerning the effectiveness of treatments, policies, and outcomes. This is especially evident during the ongoing COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To date, SARS-CoV-2 has infected over 115 million individuals and caused over 2.5 million deaths worldwide. The importance of communication around healthcare issues under such circumstances cannot be overemphasized.

All healthcare decisions come with uncertainty. In addition to the general risks that a healthcare professional is aware of, there is also uncertainty surrounding the associated probabilities, called ambiguity or radical uncertainties. These uncertainties grow as vaccines generated at an unprecedented pace are administered across the world.

Uncertainties can be 1) imprecision (e.g., 10-30% chance of benefit from treatment), 2) conflict (e.g., experts disagreeing), and 3) lack of information (e.g., insufficient evidence); all of which are present during a pandemic. In the case of vaccines, there is imprecision relating to their effectiveness and a lack of information on how they will affect transmission and restrictions, conflicting opinions may also accompany.

In addition to the prevalence of uncertainty, there is also a lack of consensus on the best ways to communicate with the people for the best possible outcomes. Studies have investigated how patients respond to communications of uncertainty, how they understand it and how it affects their decision-making.

In a different approach, researchers from University College London and the University of Warwick investigated the negative consequences of failing to communicate uncertainties. In the context of the COVID-19 vaccines, the researchers have addressed these questions in their study: Are there times where, however difficult it may be to communicate uncertainties, doing so is better than hiding them? Does failing to communicate uncertainties backfire if people find out they exist and are exposed to conflicting information? This study on how people respond to conflicting vaccine communications is recently posted on the preprint server medRxiv*.

Trust and confidence in the government official who made the vaccine announcement before receiving conflicting information (i.e. after the vaccine announcement) and after receiving conflicting information by announcement certainty.

"Our findings show that being upfront about uncertainties can maintain public trust in the long run. During a crisis like Covid-19, with so much we don't know, we are confronted with information that is constantly changing and sometimes contradictory. Anticipating this by communicating uncertainties can prevent interventions like the vaccination programme from backfiring further down the line," said Dr Eleonore Batteux, Honorary Research Fellow, Centre for the Study of Decision-Making Uncertainty – UCL, and co-author in this study.

The researchers conducted an online study with UK participants on hypothetical communications relating to the COVID-19 vaccines. The researchers conducted this survey last November 2020, before any COVID-19 vaccine announcement and its effectiveness was widely communicated.

Vaccination intention and perceived vaccine effectiveness before receiving conflicting information (i.e. after the vaccine announcement) and after receiving conflicting information by announcement certainty.

The participants (n=328) first read a vaccine announcement, which either communicated with certainty or uncertainty; followed by another information that conflicted with the initial announcement. The participants were randomly allocated to certain or uncertain communication. The hypotheses in this study were preregistered on the Open Science Framework (OSF; https://osf.io/c73px/).

The researchers found that those who were exposed to certain announcements reported a more significant loss of trust and vaccination intention than those who were exposed to uncertain announcements.

In this study, the researchers discussed their results in detail on the vaccinations, the government, the predictors of vaccination intention and the emotions involved. Participants who received the certain announcement perceived it as less effective after reading conflicting information.

Interestingly, the certain announcement led to a greater decline in trust and confidence in government officials after exposure to conflicting information.

It has been noted that perceived vaccine effectiveness mediated the relationship between communicated uncertainty and vaccination intention. With this in mind, the researchers explored if it was the case in this study too. They found that both the trust in the government official and the perceived effectiveness mediated the relationship between announcement certainty and vaccination intention.

"Although the pattern of findings on emotions is similar, the differences between those receiving the certain and uncertain announcement were less clear, perhaps due to the hypothetical nature of the study."

The researchers observed that their findings support calls for greater transparency and acknowledgments of uncertainty in communications relating to COVID-19. They highlight the advantages of communicating uncertainty, which we hope will further motivate research on doing so effectively.

In a section title, "What if uncertainties are not communicated?" the researchers investigated a novel angle for the first time. While studies indicate advantages to not communicating uncertainties, it is found that communicating with unwarranted certainty damages trust.

The participants were exposed to one instance of conflicting information. In contrast, there are likely to be many instances throughout a pandemic, the researchers warned, while discussing the limitations in this study.

In this study, the researchers examined how uncertain communications affect the trust and the vaccination intention over time, the perceived vaccine effectiveness and affective reactions after receiving the announcement to, after receiving conflicting information.

This study established that communicating with unwarranted certainty can backfire in the long-term, whereas communicating uncertainties can protect people from the negative impact of exposure to conflicting information, the researchers write.

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Dr. Ramya Dwivedi

Ramya has a Ph.D. in Biotechnology from the National Chemical Laboratories (CSIR-NCL), in Pune. Her work consisted of functionalizing nanoparticles with different molecules of biological interest, studying the reaction system and establishing useful applications.