Recent Applications of Melanin-like Nanoparticles as Antioxidant Agents.

Nanosized antioxidants are highly advantageous in terms of versatility and pharmacokinetics, with respect to conventional molecular ones. Melanin-like materials, artificial species inspired by natural melanin, combine recognized antioxidant (AOX) activity with a unique versatility of preparation and modification. Due to this versatility and documented biocompatibility, artificial melanin has been incorporated into a variety of nanoparticles (NP) in order to give new platforms for nanomedicine with enhanced AOX activity. In this review article, we first discuss the chemical mechanisms behind the AOX activity of materials in the context of the inhibition of the radical chain reaction responsible for the peroxidation of biomolecules. We also focus briefly on the AOX properties of melanin-like NP, considering the effect of parameters such as size, preparation methods and surface functionalization on them. Then, we consider the most recent and relevant applications of AOX melanin-like NPs that are able to counteract ferroptosis and be involved in the treatment of important diseases that affect, e.g., the cardiovascular and nervous systems, as well as the kidneys, liver and articulations. A specific section will be dedicated to cancer treatment, since the role of melanin in this context is still very debated. Finally, we propose future strategies in AOX development for a better chemical understanding of melanin-like materials. In particular, the composition and structure of these materials are still debated, and they present a high level of variability. Thus, a better understanding of the mechanism behind the interaction of melanin-like nanostructures with different radicals and highly reactive species would be highly advantageous for the design of more effective and specific AOX nano-agents.

COVID-19 Vaccine Refusal and Delay among Adults in Italy: Evidence from the OBVIOUS Project, a National Survey in Italy.

BACKGROUND: Vaccine hesitancy was defined by the World Health Organization (WHO) in 2019 as a major threat to global health. In Italy, reluctance to receive vaccines is a widespread phenomenon that was amplified during the COVID-19 pandemic by fear and mistrust in government. This study aims to depict different profiles and characteristics of people reluctant to vaccinate, focusing on the drivers of those who are in favor of and those who are opposed to receiving the COVID-19 vaccine. METHODS: A sample of 10,000 Italian residents was collected. A survey on COVID-19 vaccination behavior and possible determinants of vaccine uptake, delay, and refusal was administered to participants through a computer-assisted web interviewing method. RESULTS: In our sample, 83.2% stated that they were vaccinated as soon as possible ("vaccinators"), 8.0% delayed vaccination ("delayers"), and 6.7% refused to be vaccinated ("no-vaccinators"). In general, the results show that being female, aged between 25 and 64, with an education level less than a high school diploma or above a master's degree, and coming from a rural area were characteristics significantly associated with delaying or refusing COVID-19 vaccination. In addition, it was found that having minimal trust in science and/or government (i.e., 1 or 2 points on a scale from 1 to 10), using alternative medicine as the main source of treatment, and intention to vote for certain parties were characteristics associated with profiles of "delayers" or "no-vaccinators". Finally, the main reported motivation for delaying or not accepting vaccination was fear of vaccine side effects (55.0% among delayers, 55.6% among no-vaccinators). CONCLUSION: In this study, three main profiles of those who chose to be vaccinated are described. Since those who are in favor of vaccines and those who are not usually cluster in similar sociodemographic categories, we argue that findings from this study might be useful to policy makers when shaping vaccine strategies and choosing policy instruments.

Are psychological status and trust in information related to vaccine hesitancy during COVID-19 pandemic? A latent class and mediation analyses in Italy.

Despite the recognized benefits of the COVID-19 vaccination, vaccine hesitancy (VH) remains one of the biggest challenges of the mass vaccination campaign. Most studies investigating VH determinants focused on socio-demographics and direct relationships. In this study, we aimed at: 1) identifying subgroups of people differently affected by the pandemic, in terms of psychological status; 2) investigating the role of psychological status and trust in information as possible mediators of the relationship between individual characteristics and VH. To this purpose, a latent class analysis (LCA) followed by a mediation analysis were carried out on data from a survey conducted in January 2021 on 1011 Italian citizens. LCA identified four different subgroups characterized by a differential psychological impact of the pandemic: the extremely affected (21.1%), the highly affected (49.1%), the moderately affected (21.8%) and the slightly affected (8%). We found that VH decreased with the increase of psychological impact (from 59.3% to 23.9%). In the mediation analysis, past vaccination refusal, age 45-54 years and lower-than-average income, were all indirectly related to higher VH through mistrust in COVID-19 information. Differently, the psychological impact counteracted the greater VH in females, the negative effect of social media among youngest (<35 years) and the negative effect of mistrust in the lower-than-average-income subgroup. Knowledge of psychological profile of hesitant individuals, their level of trust and the sources of information they access, together with their sociodemographic characteristics provides a more comprehensive picture of VH determinants that can be used by public health stakeholders to effectively design and adapt communication campaigns.

Physical Well-Being of Children and Adolescents during the SARS-CoV-2 Pandemic: Findings from the "Come te la Passi?" Cross Sectional Survey in Bologna, Italy.

BACKGROUND: The COVID-19 had a strong impact on the physical and general well-being of the youngest. In Italy, citizens were forced to change their habits, especially during the national lockdown, causing increased levels of sedentary and unhealthy behaviors. "Come te la passi?" was a cross-sectional study aimed at investigating changes in the physical activity levels (PA) and well-being of children and adolescents in the City of Bologna. METHODS: An anonymous survey was administered to parents/guardians of children and adolescents aged 6-18 years. RESULTS: 1134 questionnaires were collected during June 2021; 457 (40.3%) were females, and the mean age was 13.0 ± 3.4 years. Regarding the general well-being perception, 61.3% of the participants reported concerns about the future, 46.3% reported sleep difficulties, and 72.8% reported experiencing attention difficulty, with higher percentages among adolescents. Considering the PA frequency, an overall reduction was found, with the percentage of those who rarely did PA and those who frequently did PA both increasing. No gender differences were found. CONCLUSIONS: Our findings suggest that the current pandemic has strongly impacted the well-being of children and adolescents. It appears to have primarily affected adolescents, with a significant reduction in PA levels, even after the end of the national lockdown.

Adherence to Herpes Zoster (Shingles) Catch-Up Campaign at the Romagna Local Health Authority (Italy), a Multi-Center Retrospective Observational Study.

Herpes Zoster (shingles) is an infection that occurs when varicella-zoster virus reactivates from the latent state. Incidence and severity of Herpes Zoster disease increase with age. Antiviral drugs are the elective treatment; however, prevention of disease reactivation through effective and safe vaccines is available in Italy out-of-pocket from age 65 onwards. The Romagna Local Health Authority (northern Italy) administered catch-up vaccinations in March-May 2022 for immunizations not performed during the COVID-19 pandemic. In this study, adherence rates to the catch-up campaign and recall activities adopted in two centers were investigated. The uptakes for only the catch-up vaccinations were 11.4% and 12.4%. Having suffered from Herpes Zoster or having family members who suffered from it would not seem to be drivers of increased uptake. Although sending text-messages to all involved patients was the main motivation for vaccine uptake (85.7-95.1%), word of mouth and web/news advertising also contributed to adoption in Center No. 2. In both centers, the need for greater synergy between public health departments and general practitioners to engage their patients emerged, as did the need for additional recall measures. Studying the main drivers of vaccine hesitancy, especially at the local level, can help in targeting campaigns and catch-up activities in order to achieve widespread acceptance.

The Role of Needle Fear in Pediatric Flu Vaccine Hesitancy: A Cross-Sectional Study in Bologna Metropolitan Area.

(1) Background: vaccination is the most effective way to prevent influenza and reduce its complications. The main aim of the study is to assess a possible increase of parents'/caregivers' pediatric flu vaccination adherence due to a nasal administration as an alternative to injection in Bologna. (2) Methods: 169 parents/guardians of children who were joining the COVID-19 pediatric vaccination session in Bologna were interviewed. The results were summarized using descriptive statistics. A multiple logistic regression model was used to assess the determinants of the change in flu vaccine uptake if offered without injection administration. All analyses were conducted using STATA and R-Studio software. (3) Results: Only 29.0% of parents were informed about pediatric flu vaccination by pediatricians, and 32.5% heard about pediatric flu vaccination. Almost 72.2% of parents declared that they would not have their children vaccinated against influenza. Thus, 40.2% of them changed their opinion after being informed about the existence of a non-injective vaccine. Needle fear in children turned out to be a determinant of this opinion change (OR = 3.79; 95% CI = 1.63-9.43; p = 0.003). (4) Conclusions: the study has confirmed that needle fear is a determinant of vaccine hesitancy and that a different method of administration may increase parents'/guardians' adherence.

Epidemiology and clinical evolution of non-multisystem inflammatory syndrome (MIS-C) dermatological lesions in pediatric patients affected by SARS-CoV-2 infection: A systematic review of the literature.

COVID-19 can present with a range of skin manifestations, some of which specific of the pediatric age. The aim of this systematic literature review was to determine the type, prevalence, time of onset, and evolution of cutaneous manifestations associated with COVID-19 in newborns, children, and adolescents, after excluding multisystem inflammatory syndrome in children (MIS-C). PubMed, Tripdatabase, ClinicalTrials, and Cochrane Library databases were searched using an ad hoc string for case reports/series and observational studies, published between December 2019 and February 2022. Study quality was assessed using the STROBE and CARE tools. Seventy-three (49 case reports/series and 24 studies) out of 26,545 identified articles were included in the analysis. Dermatological lesions were highly heterogeneous for clinical presentation, time of onset, and association with other COVID-19 manifestations. Overall, they mainly affected the acral portions, and typically presented a favorable outcome. Pseudo-chilblains were the most common. CONCLUSIONS: Mucocutaneous manifestations could be the only/predominant and early manifestation of COVID-19 that could precede other more severe manifestations by days or weeks. Therefore, physicians of all disciplines should be familiar with them. WHAT IS KNOWN: • A variety of cutaneous manifestations have been reported in association with COVID-19. • Urticaria, maculopapular, or vesicular rashes can occur at any age, while chilblains and erythema multiforme are more common in children and young patients. WHAT IS NEW: • Skin lesions related to SARS-CoV-2 infection often show a peculiar acral distribution. • Mucocutaneous lesions of various type may be the only/predominant manifestation of COVID-19; they could present in paucisymptomatic and severely ill patients and occur at different stages of the disease.

Adherence to and early adverse events of COVID-19 vaccine in a cohort of 600 Italian breastfeeding and pregnant physicians.

Pregnant and breastfeeding women (PBW) have been excluded from COVID-19 vaccine registry and the majority of post-marketing trials, despite the recognized increased risk of severe infections and complications. The lack of efficacy and safety data prevented the formulation of specific indications/guidelines for vaccination and could have also contributed to increased vaccine hesitancy (VH) in PBW. The aim of this cross-sectional study is to assess the rate and predictors of VH, and early adverse events (AEFI) following COVID-19 vaccine in PBW with a cross-sectional study. In January 2021, a purposely designed questionnaire was administered to 600 PBW part of a Facebook group of physicians, immunized with two doses of Comirnaty®. Thirty-eight (29%) pregnant women and 13 (2.8%) breastfeeders were hesitant. The only statistically significant negative predictor of COVID-19 VH appeared to be having had the flu shot in 2020/2021 (OR: 0.35; 95% CI: 0.13-0.97; p = .044). Approximately 27% of PBW reported hesitancy toward the 2020/2021 season influenza vaccine. Among the vaccinated subjects, 51.6% of pregnant and 75.2% of breastfeeding women reported at least one symptom after the first, and 82.4% and 81.6%, respectively, after the second dose. Nausea/vomiting, fatigue, headache and arthralgia/myalgia were the most common symptoms; dizziness, shivering, syncope and limb paresthesia were rarely reported. Among infants of breastfeeding mothers, six experienced fever, five rash and four moderate and self-limiting diarrhea. Preliminary data on mRNA COVID-19 vaccine in PBW and in their infants are reassuring since AEFI, although frequent, are typically mild and similar to those occurring in the general population, and in PBW after other vaccines. Larger studies with longer follow-up after vaccination are strongly recommended to develop recommendations in these patients.

Obesity and COVID-19 in Children and Adolescents: Reciprocal Detrimental Influence-Systematic Literature Review and Meta-Analysis.

The dramatic lifestyle changes forced by COVID-19-related lockdown promoted weight gain, with a stronger impact on obese subjects, at higher risk of severe infection. The PubMed database was searched to identify original studies assessing: (1) the extent and risk factors of lockdown-induced weight increase; and (2) the impact of obesity on the risk of hospital admission in children and adolescents. A systematic literature review and meta-analyses were performed. Twenty out of 13,986 identified records were included. A significant weight increase was reported in the majority of subjects, with no apparent gender or age differences. It was induced by a higher consumption of hypercaloric/hyperglycemic/junk food and/or the reduction of physical activity, often associated with an altered sleep-wake cycle. On the other hand, obesity increased the risk of hospitalization (OR = 4.38; 95% C.I. 1.46-13.19; p = 0.009; I2 = 96%) as compared to the normal weight population. COVID-19 and obesity represent epidemic conditions with reciprocal detrimental impact. Urgent public health interventions, targeting the various age and social strata, and involving governmental authorities, health care personnel, teachers and families are warranted to increase awareness and actively promote healthy lifestyles to contrast pediatric obesity and its detrimental consequences at a global level.

Obesity and COVID-19 in Children and Adolescents: Reciprocal Detrimental Influence. Systematic Literature Review and Meta-Analysis

The dramatic lifestyle changes forced by COVID-19-related lockdown promoted weight gain, with a stronger impact on obese subjects, at higher risk of severe infection. The PubMed database was searched to identify original studies assessing: (1) the extent and risk factors of lockdown-induced weight increase;and (2) the impact of obesity on the risk of hospital admission in children and adolescents. A systematic literature review and meta-analyses were performed. Twenty out of 13,986 identified records were included. A significant weight increase was reported in the majority of subjects, with no apparent gender or age differences. It was induced by a higher consumption of hypercaloric/hyperglycemic/junk food and/or the reduction of physical activity, often associated with an altered sleep–wake cycle. On the other hand, obesity increased the risk of hospitalization (OR = 4.38;95% C.I. 1.46–13.19;p = 0.009;I2 = 96%) as compared to the normal weight population. COVID-19 and obesity represent epidemic conditions with reciprocal detrimental impact. Urgent public health interventions, targeting the various age and social strata, and involving governmental authorities, health care personnel, teachers and families are warranted to increase awareness and actively promote healthy lifestyles to contrast pediatric obesity and its detrimental consequences at a global level.

ROCCA cohort study: Nationwide results on safety of Gam-COVID-Vac vaccine (Sputnik V) in the Republic of San Marino using active surveillance.

Background: Gam-COVID-Vac is the world's first registered vector vaccine against COVID-19 based on a combination of two heterologous adenoviruses. It was chosen by the Republic of San Marino as the main tool in its vaccination campaign, which started on 25 February 2021. Our aim was to build up on the ROCCA study, focused on the older population, by describing adverse effects following immunisation (AEFIs) rates and characteristics in all age groups for the first time in a real-world context. Methods: An active surveillance study on recipients of at least one dose of the Gam-COVID-Vac vaccine was conducted. Participants were administered online questionnaires through live/phone interviews with physicians, by e-mail or by scanning a QR code at different points in time after the first dose: one week (Q1) one month (Q2), and three months (Q3) between March and August 2021. Findings: Overall, 6190 vaccine recipients were recruited. Mean age was 52·4 ± 18·2 years. After the first dose, systemic reactions were reported by 57·5% of the participants, while injection site reactions were reported by 46·7%. The most common AEFIs were pain at the injection site, fatigue and headache. Grade 3 or 4 AEFIs were reported by 0·8% and 0·3% of the participants, respectively. After the second dose, systemic reactions were reported by 63·1% of the participants, while injection site reactions by 54·7%. The most common AEFIs were malaise, pain at injection site and myalgia. Grade 3 or 4 AEFIs were reported by 2·7% and 1·1% of the participants, respectively. Multivariate analysis showed younger age, being a woman and food allergies are risk factors for more severe AEFIs. Interpretation: Our results confirm a good tolerability profile for the population aged 18 and over providing useful data for vaccination campaigns ongoing in countries planning to use Gam-COVID-Vac. Funding: None.

Vaccine Hesitancy: Lessons Learned and Perspectives for a Post-Pandemic Tomorrow.

Infectious diseases have always posed a significant threat to mankind, resulting in high mortality and morbidity throughout history [...].

Sexual and Reproductive Health and Education of Adolescents during COVID-19 Pandemic, Results from "Come Te La Passi?"-Survey in Bologna, Italy.

Social distancing measures adopted to face the COVID-19 pandemic had a detrimental impact on adolescent education and their interaction with peers and adults, secondary to the limitation of school and recreational activities, with repercussions on social and sexual life. The "Come te la passi?" ("How is it going?") study, performed in the Metropolitan City of Bologna (Italy), aimed at investigating the type of information sources adopted by adolescents for their sexual and reproductive health (SRH) knowledge and education, the age of their sexual debut, and the way in which the COVID-19 pandemic affected their relationships and sexual life in order to help local health care professionals and educators designing SRH education programs. A purposely designed online survey was administered during the COVID-19 pandemic to 378 high school students (age > 14 yo) in July 2021. Based on the study results, the most common source of SRH education was the web, followed by peers (friends). A total of 61.3% of 17-year-olds already had sexual intercourse, and 90% of 15-year-olds had experienced romantic or sexual attraction. For 58.2% of the adolescents, the COVID-19 pandemic had negative effects on their relationships/sexual life. The current research emphasizes the need to involve health care professionals and educators in structured programs to promote SRH education tailored to adolescents' needs and started from early ages.

Vaccinations and Healthy Ageing: How to Rise to the Challenge Following a Life-Course Vaccination Approach.

In the context of an ageing population, one of the major Public Health goals is to promote healthy ageing. To rise to this challenge, rethinking conventional prevention paradigms and implementing them with vaccination at all stages of life is necessary. Indeed, vaccinations are able to both prevent pathogen specific diseases and all their downstream effects and to increase overall immune system plasticity and resilience. Our aim is to discuss the obstacles and opportunities in pursuing a "life-course vaccination approach" and to highlight the role of vaccines in healthy ageing. In doing so, we address the close connections between immunology and vaccinology advances and introduce the novel concept of immune fitness. Finally, we conclude that even though vaccinology is making giant steps towards tailored vaccination strategies, more studies are needed to investigate this topic.

Gam-COVID-Vac (Sputnik V) and Pfizer-BioNTech Vaccines Adverse Events following Immunization in Patients Affected by Parkinson's Disease and Multiple Sclerosis: A Longitudinal Study.

The Republic of San Marino COVID-19 vaccination campaign used Gam-COVID-Vac and Pfizer-BioNTech vaccines. To assess adverse events following immunization (AEFIs), approximately 6000 vaccine recipients were monitored by the ROCCA study, including subgroups with Parkinson's Disease (PD) and Multiple Sclerosis (MS). The purpose of this study is to evaluate short-term AEFIs through a 1-month follow-up. We conducted a longitudinal study, using active surveillance to evaluate the safety profiles of COVID-19 vaccines in PD and MS patients. Participants were actively administered a standardized online questionnaire to collect information on AEFIs. Among all PD and MS assisted by the San Marino hospital, a total of 82 patients completed the questionnaires. One week after administration of the first dose, vaccine recipients reported AEFIs in 26% of cases in the PD group, 67% in the MS group, and 68% in the control group. Participants reported slightly higher rates of AEFIs after dose 2 compared with dose 1, being 29%, 75%, and 78% for PD, MS, control group, respectively. Most of the reported symptoms were mild. Patients with PD and MS reported few AEFIs after administration of the COVID-19 vaccines. The frequency of AEFIs in the PD population was significantly lower than in the control group.

Mis-tweeting communication: a Vaccine Hesitancy analysis among twitter users in Italy.

BACKGROUND AND AIM: A previously unseen body of scientific knowledge of varying quality has been produced during the ongoing COVID-19 pandemic. It has proven extremely difficult to navigate for experts and laymen alike, originating a phenomenon described as "Infodemic", a breeding ground for misinformation. This has a potential impact on vaccine hesitancy that must be considered in a situation where efficient vaccination campaigns are of the greatest importance. We aimed at describing the polarization and volumes of Italian language tweets in the months before and after the start of the vaccination campaign in Italy. METHODS: Tweets were sampled in the October 2020-January 2021 period. The characteristics of the dataset were analyzed after manual annotation as Anti-Vax, Pro-Vax and Neutral, which allowed for the definition of a polarity score for each tweet. RESULTS: Based on the annotated tweets, we could identify 29.6% of the 2,538 unique users as anti-Vax and 12.1% as pro-Vax, with a strong disagreement in annotation in 7.1% of the tweets. We observed a change in the proportion of retweets to anti-Vax and pro-Vax messages after the start of the vaccination campaign in Italy. Although the most shared tweets are those of opposite orientation, the most retweeted users are moderately polarized.  Conclusions: The disagreement on the manual classification of tweets highlights a potential risk for misinterpretation of tweets among the general population. Our study reinforces the need to focus Public Health's attention on the new social media with the aim of increasing vaccine confidence, especially in the context of the current pandemic.

Attitudes toward the SARS-CoV-2 and Influenza Vaccination in the Metropolitan Cities of Bologna and Palermo, Italy.

Vaccine hesitancy (VH) is known to play a relevant role in thwarting the efforts toward reaching satisfactory influenza vaccination coverage, and has caused similar difficulties during the COVID-19 pandemic. This study aims to describe the phenomenon and produce insights on the reasons behind VH. A survey was administered between December 2020 and February 2021 to adults living in the cities of Bologna and Palermo. Of the 443 subjects enrolled, 47.3% were likely to get the influenza vaccination, while 75.6% were willing to receive the COVID-19 vaccination. The most frequent determinants that motivated the willingness to get the COVID-19 vaccine were trust in the safety of vaccines and belief that the vaccine is an effective tool. As for people's unwillingness to be vaccinated, being exposed to information that produced doubts about the vaccine and lack of trust in a newly developed vaccine were the most frequently involved determinants. Statistically significant positive associations were found between the willingness to be vaccinated and postgraduate education and the propensity towards influenza vaccination. A negative association with being over 40 years old and of female gender was also found. These results might have an impact in better understanding individual reasons behind VH, identifying which categories are more exposed to it and which strategies should be implemented.

ROCCA observational study: Early results on safety of Sputnik V vaccine (Gam-COVID-Vac) in the Republic of San Marino using active surveillance.

BACKGROUND: In August 2020, Sputnik V was registered as Gam-COVID-Vac by the Russian Ministry of Health, and since December 2020 it has been distributed in 61 countries worldwide. On 25 February 2021, the Republic of San Marino started its vaccination campaign, which includes Sputnik V. Our aim was to describe the adverse events following immunization (AEFIs) with this vaccine through participant-based active surveillance in the country. METHODS: Beginning from 4 March to 8 April 2021, a nationwide study was conducted on San Marino's population aged 18-89 years who received one or two doses of Sputnik V. E-questionnaire dissemination occurred through e-mails, QR-codes or live/phone interviews ~7 days after the first and second vaccine dose. A descriptive analysis was conducted to quantify AEFI incidence on both occasions, stratifying results by type and severity of symptoms. FINDINGS: Mean age of the 2558 vaccine recipients was 66±14 years. First-dose AEFI incidence was 53.3% (systemic reactions at 42.2%), while second-dose AEFI incidence was 66.8% (systemic reactions at 50.4%) (n = 1288). In general, 76.0% of two-dose recipients reported some AEFIs after either vaccine dose, and 2.1% suffered severe reactions; in 60- to 89-year-olds (n = 1021), AEFI incidence was 70.0%, with 53.0% of subjects describing systemic reactions and 0.8% reporting severe symptoms. The most frequent symptoms were local pain, asthenia, headache and joint pain. INTERPRETATION: Our results, albeit preliminary, suggest that Sputnik V has a high tolerability profile in the population aged ≥60 years in terms of short-term AEFIs. FUNDING: None.

Mass Immunization and Vaccine Hesitancy in Children and Their Families: A Long and Winding Road Ahead to Address without a Second Thought.

In 2019, vaccine hesitancy (VH), defined by the SAGE working group as "delay in acceptance or refusal of vaccination despite availability of vaccination services" [...].

Vaccine Hesitancy towards COVID-19 Vaccination: Investigating the Role of Information Sources through a Mediation Analysis.

Mass vaccination campaigns have been implemented worldwide to counteract the SARS-CoV-2/COVID-19 pandemic, however their effectiveness could be challenged by vaccine hesitancy. The tremendous rise in the use of social media have made them acquire a leading role as an information source, thus representing a crucial factor at play that could contribute to increase or mitigate vaccine hesitancy, as information sources play a pivotal role in shaping public opinion and perceptions. The aims of the study were to investigate if information sources could affect the attitude towards COVID-19 vaccination and if they could act as a mediator in the relationship between individual characteristics and vaccine hesitancy. A cross-sectional online survey was conducted by a professional panellist on a representative sample of 1011 citizens from the Emilia-Romagna region in Italy in January 2021. A mediation analysis using structural equation modelling was performed. Our results show how social media directly or indirectly increases vaccine hesitancy towards COVID-19 vaccination, while the opposite effect was observed for institutional websites. Given the global widespread use of social media, their use should be enhanced to disseminate scientifically sound information to a greater audience to counteract vaccine hesitancy, while at the same time continuing to promote and update institutional websites that have proven to be effective in reducing vaccine hesitancy.