Public views on the Covid‐19 immunity certificate: A scoping review

Abstract Introduction Already in its first implementation, the introduction of the Covid‐19 immunity certificate has generated some debate among the public. This debate might be a hindrance to the effective realization of this policy. This study aimed to systematically review published research evaluating public feeling of the Covid‐19 immunity certificate policy measure and to find which factors might influence its acceptance. Methods We followed the scoping review methods manual by the Joanna Briggs Institute. We included studies with no time limits that presented novel data, and no exclusions have been made based on study design. We excluded articles that presented just expert opinions. Results We found and reviewed 17 articles. The included studies were conducted in two main countries (the United Kingdom and Switzerland), with the rest from Israel, Italy, Spain, Germany, Australia, Taiwan and China. Both qualitative and quantitative studies were included, and nonrepresentative samples were mostly used to explore the public feeling about the Covid‐19 immunity certification. The included studies showed that public views on immunity certification are quite contradictory and influenced by age, gender, ethnicity, political orientation and attitudes towards Covid‐19 vaccination. The topic more often addressed by the included studies was the public's views on the positive and negative implications of the Covid‐19 immunity certificate in terms of ethical, legal and behavioural consequences of this measure. Conclusion The varying acceptance rates are notable and may partly be linked to differences in demographics, Covid‐19 concerns and ideological beliefs, as seen in other health‐related tracking policies. Moreover, dominant factors behind the (un)success of this policy are complex and entangled with the cultural and political dimensions rather than being just technical. For this reason, it is important to expand psychosocial research to better understand the concerns behind health certifications and allow planning of culturally based and ethically sound suitable strategies. This would be very relevant to increasing public approval and compliance with this public health measure. Patient or Public Contribution This does not apply to our work as it was a review paper.


| INTRODUCTION
Since the start of the Covid-19 vaccination campaigns, vaccine hesitancy has been recognized as one of the foremost barriers to their effectiveness. [1][2][3] As the Covid-19 pandemic continues and global vaccination campaign does not seem to be enough to effectively control the virus, many countries proceed to (re)instituting lockdowns and other restrictive public health measures to manage the spread of the disease. 2 Governments are simultaneously struggling with ways to save people from some of these restrictions.
One nonpharmaceutical initiative that is being carried out is immunity certifications (also called the 'Covid-19 immunity certificate') to exempt vaccinated people and/or those with evidence of immunity (depending on the country in which this measure has been applied) from some limitations. 3 The Covid-19 immunity certificate is a measure that aims to relax restrictions for individuals who are proved to be immune and, at the same time, to contain the contagion to recover social, cultural and working activities. 4 When compared with other incentives to tackle vaccine hesitancy, immunity certification looks like a very promising concept, as it gives incentives to people to get vaccinated without imposing a mandatory behaviour (i.e., mandatory vaccination). 5 However, even during its first adoption, this measure raised concerns 3,6,7 and generated debate among the public since it may be used as a tool for possible discrimination based on someone's health status. [8][9][10] For these reasons, opposition movements started to grow in many countries. [11][12][13] Although attitudes towards immunization certificates have been investigated by some studies, to our knowledge, this evidence has not been systematically reviewed. Therefore, this study aimed to systematically review research evaluating public attitudes towards the Covid-19 immunity certificate and to identify what factors might influence its acceptance.

| METHODS
We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines and the scoping review manual developed by the Joanna Briggs Institute. 14 According to this manual guideline, the present review was performed through the following steps.

| Stage 3: Study selection
The following inclusion criteria were used:

| Stage 5: Collating and summarizing the results
We conducted a narrative/thematic analysis of the research. The main characteristics of the studies included are reported in Table 1.
Findings about the factors that influenced Covid-19 immunity certificate public views were analysed and are presented in Table 2.

| Search results
Titles and abstracts of 1272 records were retrieved. After the removal of duplicates, 1058 records were examined. The screening process is summarized in Figure 1. Based on the assessments of titles and abstracts, 1035 records were excluded because they did not explore qualitative or quantitative data about public attitudes towards the Covid-19 immunity certificate or variables influencing the public views on this public health measure. Of the 23 fully read papers, 15 fulfilled the inclusion criteria. After the backward reference tracking, grey literature search and preprint database search, 2 further preprint studies were included, 9,23 and the final review included 17 papers.

| Country of study and year of publication
Most studies were conducted in the United Kingdom and Switzerland -respectively, four 8,17,20,27 and three 18,25,26 -and the remaining were from Israel, 27,28 Italy, 12,19 Spain, 16,20 Australia, 15,20 Japan,20 Taiwan, 20 Germany, 20 United States of America and 22 China. 23,29 Only one study did not report the country of data collection because it was conducted on Twitter. 24 The studies were published between 2020 25 and 2022. 24 17 For the only one retrieved qualitative study, the sample included 68 participants. 18

| Study methods
Fourteen studies used quantitative methods, one study used qualitative methods and two studies adopted a mixed-methods design applied to the analysis of web conversation. The majority are quantitative cross-sectional surveys (n = 14). For qualitative research, the included study adopted focus groups and interviews. Studies on web conversation analysis adopted a mixed-methods approach.

| Main findings
In the following paragraphs, we present a narrative synthesis of the main topics associated with the public attitudes towards the introduction of the Covid-19 immunity certificate. The topic more  Not specified This study is aimed at understanding the positive and negative discourse surrounding the Covid-19 passport system.  18 Switzerland Few participants considered immunity certificates based on serological testing as an acceptable public health measure.

N/A
On the one hand, participants reported some benefits related to the immunity certificate, such as increasing intentions to get vaccinated, gain medical knowledge and protection in a certain context involving leisureor work-related activities.
On the contrary, some harms were also reported: discrimination, counterfeiting, incitement to selfinfection, invasion of the private sphere, violation of personal integrity and violation of medical secrecy were perceived as the major risks. Immunity passport support was moderate to low, ranging from 51% in the United Kingdom and Germany, down to 22% in Japan.
• Gender • Attitudes towards the Covid-19 immunity certificate • Covid-19 concern • Political orientation Green et al. (2021) 21 N/A Immunity passports were mostly supported when participants were exposed to information presented with sensitivity towards the current scientific consensus concerning infection-acquired COVID-19 immunity.
• Evidence-based policy introduction Hall et al. (2021) 22 USA 45.2% of respondents supported immunity privileges, with slightly more favouring private certificates than government passports. Support was greater for using passports or certificates to enable return to high-risk jobs or attendance at large recreational events than for returning to work generally. • Trust in government • Conspiracy theory inclinations • Covid-19 immunity certificate information literacy • Self-efficacy Travel emerged as the dominant theme. There were 137 tweets (29.5%) that referred to travel as a benefit of having some sort of a COVID-19 passport, followed by social (4.3%) and economic benefits (3.9%).

Lewandowsky et al. (2020) 8
The United Kingdom Most people did not object to the idea of passports, with the concern being low on average and more than 60% of people wanting one for themselves to varying extents. There were, however, around 20% of respondents who considered passports to be unfair and who opposed them completely.
• Age • Attitudes towards the Covid-19 immunity certificate • Covid-19 concern • Trust in government Mayssam et al. (2020) 25 Switzerland About 80% of participants agreed that knowing one's serology status would lead to a change in one's behaviours. In the event that the presence of antibodies correlated with immunity, 60% of participants reported that certificates should be offered to the general population. The results showed variations in attitudes towards certificates depending on the context (73% agreed on certificates' utility for travel, 72% for entering a country and 32% for the right to work). Provided an effective vaccine was available, 55% of participants agreed that vaccination should be mandatory and 49% agreed that a vaccination certificate should be mandatory.  Table 2.
Most studies reported that the majority of respondents are favourable to the adoption of immunity certificates. 8,15,17,[23][24][25][26] One study reported that 49% of the population think that immunity certification should be mandatory. 25 However, limited research found the opposite result. For instance, Gallè et al. 22 found that only 33% of respondents were favourable of this measure. Even Garret et al. 20 found that immunity certificate support was moderate to low, ranging from 51% in the United Kingdom and Germany and down to 22% in Japan. Other studies reported opinions that support immunity certificates only for specific work-related contexts 18 and not for attending large gatherings or social venues. 26 Other research reported a favourable public opinion towards the adoption of an immunity certificate for crossing international borders, taking a plane or avoiding quarantine related to travel. 25

| Perceived benefit
Arguments in favour of the Covid-19 immunity certificate were related to some individual and collective benefits they could provide.
Regarding the individual benefits, the included studies highlighted that there are some main reasons behind the public positive attitudes towards the certificate. First, the introduction of an  Classifying people based on their COVID-19 situation could lead to discrimination between the vaccinated and the unvaccinated.

| Perceived harms
Moreover, some authors suggested the risk of work-related discrimination in terms of reduced employment opportunities for those who do not have immunity certificates. 18,25 Freedom of movement is another concern that could become a problematic issue, especially for people who would not be able to take the vaccine because of health constraints. 16 This would imply that individuals not yet vaccinated will not be able to go on international travel or may suffer domestic and local mobility restrictions. 16 Immunity certificates were also perceived as an invasion of the private sphere and a violation of personal integrity. The public reported worries about the privacy of their health data. The risk of the violation of medical secrecy was also often highlighted. 18 The economic value of the immunity certificate was also reported as an incentive to expose oneself to catch the disease, often expressed as an encouragement to take part in 'corona parties'.  23,26 and professional status 26 were the most common significant factors reported. White individuals and older people who have high-income status were generally more likely to report positive attitudes towards the vaccines. The variable of level of education seems to be more controversial in its impact on attitudes.
More educated people have been found to be more sceptical of and worried about the Covid-19 immunity certificate due to possible risks of discrimination in some studies. 18,25,29 In other studies, more educated individuals have been found to be more inclined to this measure when it is related to attending work settings where there is a high risk of infecting vulnerable people. 26 Most of the studies reported that men were more willing to accept the Covid-19 immunity certificate than women. 15,22,25,26 Regarding ethnicity, one study found that Hispanic people or individuals belonging to ethnic minorities are less prone to accept the Covid-19 immunity certificate. 22 Finally, some studies revealed that professional status might be an influencing factor in the public attitude towards the Covid-19 immunity certificate. 25,26 For instance, working people seem to be less favourable than unemployed people or students. 25  both related to a positive judgement of the immunity certification.
Additionally, people's ethical perceptions may serve as important catalysts for influencing attitudes towards immunity certificates: when citizens consider immunity certification as fair (moral equity), required by people belonging to the individual's social network-such as family, friends and colleagues-(relativism), a positive measure to attain personal objectives (egoism), also providing a social utility (utilitarianism), this becomes an acceptable mandate. 16 Public opinion on this issue may also be influenced by political inclination and global perceptions 15,20,23 : according to one study, neoliberal worldviewswhich consider the free market as fair and as operating best when unrestricted by government intervention-improve popular support for immunity certificates. 20 Another study on international scientists showed that those who hold more conservative views (more rightwing) are significantly more in favour of immunity certificates. 15 By contrast, opposition towards immunity certificates is linked to a communitarian approach to public health, which is in line with progressive views. 15,30 A further factor that appears to influence public feelings on this issue is racial and cultural background. In one study, researchers found that while in the Western setting sentiments about the adoption of immunity certificates are more influenced by societal factors than by personal risks and advantages, 20 in Eastern countries, the latter seems to have a more remarkable role, as a positive and robust association between subjective norms, nationalism and positive attitude to Covid-19 immunity certificates has been found. 23 Finally, mistrust towards government and individuals' conspiracy theory inclination are related to negative attitudes towards immunity certificates. 8

| CONCLUSION
While providing information to the public about the implications of immunity certification policies is essential, this study showed that they need to be complemented by trust-building and culturally sound strategies to sustain their acceptance. 39 Indeed, these policies have been currently adopted to various extents across many countriesfrom limiting travel to restricting admission to social venues and public events. 40 While it is probably too early to have an overall understanding of the implications of these policies, collecting data on these experiences is helpful in not only supplying feedback to revise the implementation of such measures but also in mitigating in 'real

DATA AVAILABILITY STATEMENT
Data are available upon request from the corresponding author.

ETHICS STATEMENT
Ethical approval for this type of study is not required by our institute.