Table 1.

Key results from selected studies.

Reference Article	Aim of the Study	Key Points about Green Pass	Proposed Recommendations
Montanari Vergallo et al. COVID-19 vaccine mandates: what are the current European public perspectives? [15].	To elaborate on the European policy choices for the prevention of SARS-CoV-2 contagion, with a close focus on the rules and regulations enacted in Italy so far.	The COVID-19 vaccination certificate refers to the EU Regulation 2021/953, of June 14, 2021, which established the Green Digital Certificate to facilitate the resumption of economic and social activities among European countries and within the Schengen area, and to stave off discriminatory practices between vaccinated and unvaccinated citizens. As for the implementation of “moral persuasion” policies, the European Union has not taken a joint decision about this Certificate, thus allowing each member state to introduce its own rules. The COVID-19 vaccination certificate has proven effective in increasing vaccination rates, but has sparked widespread protests in Europe, because it is viewed by some as a form of discrimination between those who have it, and can therefore exercise their constitutionally guaranteed freedoms, and those who do not and, therefore have such rights suspended. Such a discriminatory mechanism may not be warranted in terms of security and prevention. From the perspective of risk-benefit analysis, the vaccine has certainly been beneficial and greatly valuable for our community as a whole. Less acceptable is the policy of applying such different, uneven rules between vaccinated and unvaccinated citizens.	A strategy focused on persuasion and personal conviction is likely preferable and more in keeping with the system of safeguards for personal freedom. Only absolute clarity and straightforward information can help tackle vaccination hesitancy, in the general population and among fragile segments. Promoting public discussion between experts and citizens can go a long way towards raising awareness among the citizenry and shed light on confusing aspects. In order to deal more effectively with COVID-19 and its variants, vaccines or tests are not enough, if not coupled with a solid and clearly defined prevention strategy (such as reorganizing the health system in general and strengthening territorial medicine, intervening in the all-too-common phenomenon of overcrowded schools and classrooms, enhancing distance learning, to laying out the improvement of public transportation; to ensuring vaccines are made accessible even for countries that do not have sufficient resources to buy the drug). Policies should follow more logical and evidence-based rules. The duty of solidarity that each country has asked its citizens to fulfill, by encouraging them to become vaccinated, is ultimately insufficient.
Pamieri et al. De Jure and De Facto: An Overview on the Italian Measure in Compulsory Vaccination [22].	To trace the most important profiles of the vaccination obligation implemented de jure and de facto by the Italian government.	In August 2021, the COVID-19 Green Certification System was implemented in Italy as proof of vaccination, recovery, or a negative test result. However, since this first provision, the framework of measures in force today has evolved considerably, demonstrating an attempt to implement a growing policy of control over the spread of infection. Of the various changes made to date, the most noteworthy is the amendment made by Decree No. 172 of November 2021.20 This Decree marked the implementation of a second COVID-19 Certification, called the Green Pass Rafforzato (“Enhanced”) (or Super Green Pass), along with the existence of the Basic Green Pass. With the increase in the number of activities for which a Super Green Pass is required, the government has taken an even stronger stance on COVID-19 vaccination, imposing a sort of de facto compulsory vaccination for access to social life. Although, bys placing the word “compulsory vaccination” on a few categories of citizens, the Italian government has created a comprehensive architecture in which very few citizens can live their lives without fulfilling the, de jure or de facto, compulsory vaccination.
Reno et al. The impact of health policies and vaccine rollout on the COVID-19 pandemic waves in Italy [29].	To describe the impact of vaccine rollout and health policies on the evolution of the COVID-19 pandemic in Italy from March 2020 to October 2021 using a set of epidemiological indicators.	In order to promote immunizations, Italy adopted a Green Pass in July 2021, and policies were developed for its implementation and use. With this certificate, people can have access to indoor restaurants, bars, theaters and other recreational venues. It is also needed to attend schools and universities. In summary, the Green Pass was implemented as a measure to encourage compliance with vaccination, increase the population’s immune coverage, and therefore reduce the circulation of the virus, allowing the “reopening” of the country. The vaccination strategy adopted as well as policies targeted to make the vaccine available (active offer of the vaccination and vaccination hubs) together with a nudging strategy (the Green Pass) had a great impact on the diffusion of the infection and the number of hospitalizations and deaths.	The study illustrated the importance of multifaceted interventions as tools to help encourage compliance with immunization.
Stefanizzi et al. Vaccination strategies between compulsion and incentives. The Italian Green Pass Experience [30].	Editorial about the Italian Green Pass experience.	The Italian Green Pass experience showed good effect of this approach in increasing immunization coverage. More than 20% of people did not have access to immunization, with a proportion of 22.6% among people aged 12–49 years and 32.8% among people aged 12–19 years.	Due to the fact that the Green Pass did not seem able to reach the last group of vaccine skeptics or no-vax people, the Italian Government now has to consider the opportunity to introduce the mandatory SARS-CoV-2 vaccination, to better ensure the health of the most vulnerable population.
Spitale et al. Concerns Around Opposition to the Green Pass in Italy: Social Listening Analysis by Using a Mixed Methods Approach [31].	To understand and describe the concerns of individuals opposed to the Green Pass in Italy, the main arguments of their discussions, and their characterization.	The declared aim of the “green passport” was to encourage citizens to receive COVID-19 vaccinations while allowing some reopening of the economy. Compared to other nudging strategies to tackle vaccine hesitancy, the Green pass appears to be a promising concept, as it incentivizes people to get vaccinated without imposing a decision. However, it has generated some debate as it can be considered a tool for discrimination based on someone’s vaccination status. The Green Pass raised an argument with regards to privacy as well: when showing their Green Pass, people are de facto obliged to disclose health information to third parties. The Green Pass has become a proxy and a catalyzer for vaccine skepticism: people generally do not argue their opposition to the Green Pass with antivaccine rhetoric but rather focus on the legal aspects and limitations of personal freedom. This opposition to the Green Pass is often justified on the grounds of a naïve idea of freedom, conceptualized in a jurisprudential, consequentialist, or deontological form.	Acknowledge the doubts of individuals opposed to the Green Pass without dismissing their opinions and arguments as ramblings. Disambiguate the purpose of the Green Pass: it should be made clear that it is a tool intended to incentivize vaccinations and thus protect people. Counteract the models of freedom in which the opposition to the Green Pass is grounded, offering alternatives. Clarify the legal basis of the Green Pass, explaining how it is founded and regulated in existing jurisprudence, and how its scope and application are defined and limited by the contingency of the pandemic. Keep informing about vaccines, with a specific focus on transparency and risk-benefit balance. The key ethical question is therefore how effective communication and management during important public health crises such as pandemics is possible without undermining privacy as a human right. Active social listening—intended as actively asking people their opinion on delicate topics such as vaccine distribution strategies or safety measures - can build trust rather than undermine it further. Engaging directly with communities by offering concerned people the possibility to voice their worries can create a sense of not only being listened to but also of being heard, recognized, and valued.
Moccia et al. Vaccine Hesitancy and the Green Digital Pass: A Study on Adherence to the Italian COVID-19 Vaccination Campaign [32].	To investigate the phenomenon of vaccination hesitancy and the underlying reasons, as well as any changes to the membership following the obligation of the Green Pass.	COVID-19 certificates should be examined within the overall broader regulatory response to the COVID-19 pandemic, which has been characterized by widespread limitations on different human rights: mobility, curfews, closure of educational institutions, and restrictions of commercial activities. The necessity for the creation of COVID-19 certificates must, therefore, be found in the need to alleviate some of the limitations placed on the general population. The COVID-19 certificate is to “facilitate safe free movement” in Europe, and it represents a tool for the regulation and governance of the pandemic, as well as for the wider governance and regulation of populations and territories, including the regulation of access to fundamental human rights. Tools, such as the Digital Green Pass, are useful for achieving overall behavioral change and effects on wellbeing, but they could harm identifiable social groups.	Trust in scientists and domestic healthcare professionals, combined with confidence in the WHO, represents an important driver of vaccine acceptance across the globe. Therefore, for trust and confidence, political leaders should assign resources to the management and communication of vaccine safety, its effectiveness, and distribution protocols to scientists and health professionals. Health professionals should, in turn, participate in developing and deploying communication strategies.
Gallè et al. Acceptance of COVID-19 Vaccination in the Elderly: A Cross-Sectional Study in Southern Italy [33].	To assess, through an online questionnaire, the acceptance of COVID-19 vaccination in a sample of older adults from southern Italy during the national vaccination campaign.	A lower vaccine acceptance was associated with the date of questionnaire fulfillment (after the mandatory implementation of the Green Pass). Mandatory measures such as the compulsory adoption of a vaccine passport may be interpreted as a threat to human rights and civil liberty, and thus decrease vaccine acceptance.	Compulsory measures must be accompanied by effective education and information strategies for the target population, paying attention to the spread of data not supported by scientific evidence. In this context, the role of reference healthcare personnel is crucial. At the same time, communication campaigns based on mass media should be tailored to those categories. Interventions supporting individuals’ autonomous motivation to get vaccinated should be programmed and implemented besides compulsory provisions of law, even in non-pandemic times. The early development of national public health laws and policies to provide a proportionate and graduated approach to compulsory vaccination in the context of a global health crisis, besides effective information campaigns, may represent an effective preparedness strategy.
Mills et al. The effect of mandatory COVID-19 certificates on vaccine uptake: synthetic -control modelling of six countries [34].	To investigate the effect of certification on vaccine uptake by designing a synthetic control model comparing 6 countries (Denmark, Israel, Italy, France, Germany, and Switzerland) that introduced certification (April–August, 2021), with 19 control countries.	For Italy, we also found a strong anticipation effect before the announcement of COVID-19 certification, followed by a decrease slightly below the average of the synthetic control group. At 30 days after implementation, daily doses in Italy were 1370 doses (1177–2421) greater than those in the synthetic control group, again suggesting a positive relationship between certification and vaccine uptake. In Italy, the youngest age group (18–24 years) had an increase in daily vaccinations directly before and after the intervention and another increase 2–3 weeks after certification. This analysis suggests that those younger than 20 years and aged 20–29 years old had increased uptake.	Although we found that certification increased vaccine uptake in certain settings and groups, COVID-19 certification alone will not increase vaccine uptake among all groups. Other measures such as geographically targeted vaccine drives or peer-to-peer and community dialogue within low-trust groups to generate understanding might be more effective for certain groups.
Oliu-Barton et al. The effect of COVID certificates on vaccine uptake, health outcomes, and the economy [35].	To estimate the effect of COVID-19 certificates on vaccine uptake for France, Germany, and Italy using counterfactuals constructed via innovation diffusion theory.	COVID-19 certificates may spur economic recovery in the short run, as newly vaccinated people can safely resume in-person economic activities, including working on-site, and consuming goods as well as services in brick-and-mortar businesses. By increasing vaccine uptake, COVID-19 certificates reduced the number of patients in ICUs and thus contributed to reducing the likelihood of stricter public measures, including lockdowns. COVID-19 certificates were associated with a sizeable, robust positive effect on vaccination rates, health outcomes, and the economy in France, Germany (albeit only significantly towards the end of 2021), and Italy. COVID-19 certificates appear to be an attractive, more inclusive alternative to vaccine mandates, focusing on the added benefits of getting vaccinated or tested rather than on punitive measures for not doing so.	The governments’ policy decisions on COVID-19 certificates should also consider additional factors, including the supply of vaccines and tests, political trust, and accessibility for marginalized groups, in order not to threaten social cohesion or exacerbate already existing inequities. International coordination and mutual acceptance of COVID-19 certificates are crucial to prevent deepening the divide between different regions.
Gometz. Green pass e discriminazione [36].	To analyse green pass certification criticism and the related conceptual and normative assumptions in order to provide an opportunity for reflection on the notion of discrimination and its criteria and conditions of employment.	The Green Pass is an effective health risk containment measure not only because it reduces opportunities for interpersonal contact between individuals who—considered in general—are at greater risk of becoming infected and infecting their neighbor, but also because it provides a formidable incentive to vaccinate of fearful citizens, the ill-informed, and the reluctant to the bitter end, as evidenced by the sudden increases in vaccination bookings recorded in Italy after the news about the adoption of the Green Pass and the extension of its mandate to most workers. Those who consider the Green Pass as intolerable discrimination, sometimes even comparing it to the membership card of the National Fascist Party or contrasting it with the yellow star or the mark on the skin of Jews during Nazism, have the burden of explaining why it is not in the same category and incite the related amount of indignant disapproval to stigmatize regulations reserving the driving of motor vehicles for those with a license, a college degree for those who pass their exams, and ownership of real estate for those who have purchased it in one of the ways established by law. The explanation cannot be based on convictions, personal beliefs, and opinions, which here, as we have seen, are totally irrelevant. Except, perhaps, to base unflattering judgments on the common sense of the bearer.	The problem of fake news in health care can possibly be addressed by the inclusion of elements of epistemological literacy in school and university curricula.
Ferraro. Passaporto vaccinale e discriminazione: stigma sociale e disuguaglianza giustificata [37].	To address accusations of state discrimination against those who are not vaccinated by choice or for health reasons related to the introduction of the COVID-19 vaccine certification in Italy.	The claim, leveled at the introduction of the Green Pass, that it constitutes a discriminatory measure against the nonvaccinated is implausible if we are talking about direct discrimination. On those who make such an accusation falls an argumentative burden: they should show that the unequal treatment in question is unjustified, taking due account of the fact that other public policy alternatives for managing and containing COVID-19 infection - or rather, the health impact of such infection - are all, at least at first glance, less palatable. If we look at the “ expressive” aspect of discrimination, related to the social stigma that the adopted measures would place on those who do not vaccinate, the opponents of the Green Pass may be right.	It is necessary to accompany the Green Pass with measures to combat marginalization, offset social injustices and inequalities, and adequately explain the good reasons supporting the vaccine passport. The proper communication of the justifications for such policy choices may help to create a context in which these choices do not express debasement and humiliation, becoming prima facie discriminatory. The accurate and truthful data on vaccine safety and efficacy is equally imperative.
Mori. Sul significato etico e filosofico del “Green Pass” o “Passaporto Vaccinale”: Un contributo alla riflessione [38].	To contribute to the current debate on the COVID-19 pandemic and its consequenc-es.	Since the strong and qualifying point of the Green Pass is vaccination, on a cultural level, the implementation of this document entails: (1) the affirmation of the concept of health as a social construct and, (2) the affirmation of the principle that when there is a dan-ger or harm to the health of others, it is permissible to restrict some freedoms.