Vaccination In Italy Research Articles

Health Technology Assessment of Vaccines in Italy: History and Review of Applications

Background/Objectives. Many vaccines have been developed in recent decades, and many more will be available in the future. When new safe and effective vaccines are available, decision-makers must extensively assess them before including them in the national immunization plan and issuing recommendations. The Health Technology Assessment (HTA) could be an objective, transparent, and comprehensive approach to guiding the decision-making process for the use of vaccines. Objectives and Methods. The aim of this study was to review the indications for HTA use contained in Italian institutional documents on vaccination, namely the National Immunization Plans (NIPs) and available full Italian HTA reports on vaccines, assessing their availability at the time of national recommendations’ introductions. Results. HTA has been recognised as an eligible approach to deciding upon the introduction of vaccines through the NIPs of 2012–2014 and 2017–2019, and the last NIP, of 2023–2025, highlights the lack of funding dedicated to the production of independent HTA reports that can be used for issuing recommendations. In 2007–2023, twenty full HTA reports on vaccines were published in Italy: eight reports on influenza vaccines, five on Human Papilloma Virus (HPV), three each on meningococcal and pneumococcal vaccines, and one on rotavirus vaccine. HTA was applied with different purposes, namely the evaluation of new vaccines or their re-assessment, but it was not always timely with respect to both the marketing authorisation and the issuing of national recommendations for use. Conclusions. As HTA can be considered the best tool to disentangle the overall value of vaccines, it would be desirable for it to be used more and more to provide the evidence for efficient resource use. This calls for action to improve the transfer of HTA results to decision-makers, to try to fill the gap between research and decision and foster evidence-based recommendations.

Unveiling the Burden of Hepatitis A in Salerno, Italy: A Comprehensive 9-Year Retrospective Study (2015-2023) on the Seroprevalence of HAV Antibodies and Age/Sex Distribution.

Background: Hepatitis A virus (HAV) infection is a significant global cause of viral hepatitis. At present, the anti-HAV vaccine in Italy is proposed exclusively for specific high-risk groups, and a universal vaccination program is not implemented. Objectives: This study aimed to assess the level of immunity against HAV in patients of both sexes across age groups ranging from 0 to 95 years admitted to the San Giovanni di Dio e Ruggi d'Aragona Hospital in Salerno, Italy, over a 9-year period (2015-2023). Methods: The total HAV seroprevalence by chemiluminescence Vitros system immunodiagnostics (ortho-diagnostics) was obtained by database analysis, stratifying patients for gender and age group in both the pre-pandemic (2015-2019) and pandemic (2020-2023) periods. Results: Out of 28,104 samples collected in 2015-2023, 20,613 resulted positive by total HAV immune screening, with a significant reduction in the annualized proportion of events during the pandemic period compared to the pre-pandemic period. HAV was more abundant in males than females in both periods (exceeding the 70%), with a statistically significant decrease in HAV in females in 2015-2019. The 61-70-year-old age group is more susceptible for both genders, with a strong deviation from the 41-50-year-old age group compared to the 51-60-year-old group. The pandemic period affected the number of analyzed samples in 2020. Conclusions: The study revealed high HAV seroprevalence, especially in males and individuals aged 61-70 years. There was a notable decrease in seroprevalence during the pandemic compared to pre-pandemic years. These results emphasize the need for ongoing monitoring and suggest that a universal vaccination program could address regional immunity gaps and lower disease incidence.

Acute Appendicitis After COVID-19 Vaccines in Italy: A Self-Controlled Case Series Study.

Cases of appendicitis were identified in the pivotal randomized clinical trial on BNT162b2 mRNA vaccine and reported from coronavirus disease 2019 (COVID-19) vaccine pharmacovigilance systems. Three cohort studies and two self-controlled case series (SCCS) studies evaluating the association between mRNA vaccines and appendicitis reported discordant results. To address this uncertainty, the present study examines in a large population, with a SCCS design, the association between mRNA (BNT162b2 and mRNA-1273) and, for the first time, viral vector (ChAdOx1-S and Ad26.COV2-S) COVID-19 vaccines and acute appendicitis. The SCCS study design was used to evaluate the association between COVID-19 vaccination and subsequent onset of acute appendicitis. The study was based on record linkage of health archives through TheShinISS application, a statistical tool that locally processes data from regional health care databases according to ad hoc, study-tailored and common data model. The study population included all vaccinated subjects ≥ 12 years old between 27 December 2020 and 30 September 2021. The acute appendicitis was identified through discharge diagnoses of hospital admissions or emergency department visits. Incident cases were defined as those who experienced a first event of acute appendicitis in the study period, excluding subjects with a diagnosis of appendicitis in the previous 5 years. Exposure was defined as the first or second dose of BNT162b2, mRNA-1273 and ChAdOx1-S and the single dose of Ad26.COV2-S. The risk interval was defined as 42 days from the first or second vaccination dose and divided into pre-specified risk subperiods; the reference period was the observation time outside the risk interval. Relative incidences (RI) and 95% confidence intervals (95% CI) were estimated with the SCCS method 'modified for event-dependent exposures', through unbiased estimating equations. The seasonal component was considered as a time-dependent covariate. In the 42-day risk interval 1285 incident cases of acute appendicitis occurred: 727 cases after the first dose and 558 cases after the second dose. In the main analysis, no increased risks of acute appendicitis were observed in subjects vaccinated with BNT162b, mRNA-1273, ChAdOx1-S and Ad26.COV2-S. The subgroup analyses by sex showed an increased risk in the 14-27 day risk interval, in males after the first dose of mRNA-1273 (RI of 1.71; 95% CI 1.08-2.70, p = 0.02) and in females after the single dose of Ad26.COV2-S (RI of 4.40; 95% CI 1.29-15.01, p = 0.02). There was no evidence of association of BNT162b, ChAdOx1-S, mRNA-1273 and Ad26.COV2-S with acute appendicitis in the general population. The results of the subgroup analyses by sex needs to be considered with caution. The multiplicity issue cannot be excluded being these hypotheses two of several hypotheses tested. In addition, relevant literature on the biological mechanism of the disease and evidence of similar effects with other vaccines or with the same vaccines are still lacking to provide strong support for a conclusion that there is an harmful effect in males and females with mRNA-1273 and Ad26.COV2-S.

Successful Elimination of Endemic Rubella in the WHO European Region. Is It Proper to Remove the Recommendation for Preconceptional Immunization?

Rubella is a contagious viral infection that has garnered significant attention in the field of public health due to its potential consequences, especially during pregnancy. In recent decades, it has been recommended that non-immune women receive immunization during the preconceptional and/or postpartum periods. The goal of this strategy is to prevent primary rubella infection in order to protect pregnant women against congenital rubella syndrome. In November 2022, the WHO's Regional Verification Commission declared the elimination of rubella infection in Italy. In recent years, the main migration flows to Italy have originated from regions where rubella has not yet been eliminated and where no program is in place to achieve this goal. The aim of this study was to retrospectively assess rubella immunity in pregnant women who have attended three delivery centers in Rome over the past three years, from January 2021 to May 2023. Data about the rubella serological status of 7937 non-consecutive pregnant women were collected. Univariate analysis was performed to verify any difference between the study groups in terms of age distribution. Anti-rubella IgG antibodies were found in 7224 (91%) women while 713 (9%) were susceptible to rubella (IgG negative), without differences in terms of immunity rate between Italian and non-Italian women. Age analysis showed a statistically significant older age of immune women than receptive women and of Italian immune women than non-Italian immune women. The National Plan for the Elimination of Measles and Congenital Rubella aimed to achieve a percentage of susceptible women of childbearing age below 5%. These data indicate the relevance of maintaining the recommendation for preconceptional rubella vaccination in Italy.

Epidemiology and burden of respiratory syncytial virus in Italian adults: A systematic review and meta-analysis.

Respiratory syncytial virus (RSV) is a common respiratory pathogen not only in children, but also in adults. In view of a recent authorization of adult RSV vaccines in Italy, our research question was to quantify the epidemiology and burden of RSV in Italian adults. Observational studies on the epidemiology and clinical burden of laboratory-confirmed or record-coded RSV infection in Italian adults of any age were eligible. Studies with no separate data for Italian adults, modeling and other secondary publications were excluded. A literature search was performed in MEDLINE, Biological Abstracts, Global Health, Scopus and Web of Science on 22 November 2023. Critical appraisal was performed by means of a Joanna Briggs Institute checklist. Random-effects (RE) meta-analysis was performed to obtain pooled estimates and the observed heterogeneity was investigated by subgroup and meta-regression analyses. The protocol was prospectively registered (doi.org/10.17504/protocols.io.5qpvo32odv4o/v1). Thirty-five studies were identified, most of which had at least one possible quality concern. RSV seasonal attack rates ranged from 0.8 ‰ in community-dwelling older adults to 10.9% in hematological outpatients. In the RE model, 4.5% (95% CI: 3.2-5.9%) of respiratory samples tested positive for RSV. This positivity prevalence was higher in older adults (4.4%) than in working-age adults (3.5%) and in outpatient (4.9%) than inpatient (2.9%) settings. According to the meta-regression, study location and sample size were also significant predictors of RSV detection frequency. The pooled estimate of in-hospital mortality was as high as 7.2% (95% CI: 4.7-10.3%). Data on other indicators of the diseases burden, such as complication and hospitalization rates, were unavailable. RSV poses a measurable burden on Italian adults, especially those of older age and with some co-morbidities. However, several data on the natural history of RSV disease are missing and should be established by future large-scale studies.

EE590 Assessing Health Outcomes and Cost-Effectiveness of Adult HPV Vaccination in Italy

EE590 Assessing Health Outcomes and Cost-Effectiveness of Adult HPV Vaccination in Italy

The impact of rotavirus vaccination in Italy: an eleven-year (2009-2019) nationwide analysis

Abstract Although the positive effects of the introduction of rotavirus (RV) vaccination in Italy, a national updated analysis of its effect in still lacking to date. This study aims to analyze the implementation of rotavirus vaccination in Italy, evaluating its impact on discharges for acute pediatric gastroenteritis. A retrospective analysis including hospital discharge records and data on vaccination coverage for children aged 0-71 months from 2009 to 2019 was conducted. We examined trend in hospital discharge standardized incidence before and after vaccine introduction using a negative binomial mixture model with fixed effects to evaluate the impact of universal vaccination. The percentage of vaccination coverage increased over the years, from < 5% between 2009 and 2013 to 26% in 2017. After the inclusion to the National Im-munization Plan, in 2019 over 70% of children received the vaccine. In the first phase (2009-2013), the standardized incidence of discharges was 16.6/100,000 inhabitants; it decreased in the second phase (2014-2017) reaching 14.1/100,000 inhabitants. During the third phase (2018-2019) it significantly decreased to 9.9/100,000 inhabitants. In this phase, about 15% of the estimated hospital discharges were avoided compared with those estimated using the first phase data. The implementation of rotavirus vaccination reduced acute pediatric gastroenteritis incidence discharges in children aged 0-71 months. Further efforts are needed to continue monitoring the vaccination effect over time and to increase vaccination coverage. Key messages • The implementation of Rotavirus vaccination in Italy resulted in a reduction of acute pediatric gastroenteritis. • Further efforts are needed to maintain high vaccination coverages, thus reducing the negative impact of rotavirus disease.

Trend in mandatory vaccination coverage in Italy from 2000 to 2021. A joinpoint Regression Analysis

Abstract Introduction Vaccination is one of the most effective public health interventions, preventing more than 4 million deaths each year. However, the complex and multifactorial phenomenon of vaccine hesitancy has increased over the years, causing a reduction in vaccination coverage (VC) and the resurgence of epidemics from vaccine-preventable diseases (VPD). Moreover, the COVID-19 pandemic had a major impact on the capacity of health systems to continue the delivery of essential health services, including vaccination. In this context, the objective of this study is to analyse the trend of 10 vaccinations in Italy (measles, mumps, rubella, tetanus, diphtheria, pertussis, chickenpox, hemophilus, hepatitis B, and polio), from 2000 to 2021, evaluating the impact of the introduction of the mandatory law in 2017 and the pandemic. Methods Data were obtained from the Italian Ministry of Health. The joinpoint regression model was used to estimate changes in vaccination coverage trends for each indicator. It allows estimation of an annual percentage change (APC) in vaccination coverage, reflecting an increase or decrease over time. For each indicator, the presence of a joinpoint expressed significant changes in APC trends. APC was considered significant when p < 0.05. Results Until 2017, a gradual decline in VC is observed, with values below 95% for all indicators considered. For all indicators analysed, an increase (p < 0.005 for measles and chickenpox) in VC is observed following the mandatory law of 2017. Similarly, a reduction in all values is observed from 2020 (p < 0.005 for Tetanus). Conclusions The mandatory law represented an effective intervention, leading to an increase in all VC, which for 6 vaccinations reached a value >95%. On the other hand, the pandemic had a significant impact on the reduction of VC in Italy. It is necessary to plan recovery interventions for children in pandemic-affected cohorts to ensure adequate VC values and avoid epidemics from VPD. Key messages • The mandatory law represented an effective intervention increasing vaccination coverage. • It is necessary to plan recovery interventions for children in pandemic-affected cohorts to ensure adequate vaccination coverage.

An integrated infoveillance approach using google trends and Talkwalker: Listening to web concerns about COVID-19 vaccines in Italy

An infodemic is an information epidemic capable of compromising public health. This manuscript proposes an infoveillance method suitable for listening to web concerns on health to develop adequate infodemiological responses based on the World Health Organization indications. In particular, the case of COVID-19 vaccinations in Italy was investigated. Web interest and concern in COVID-19 vaccines over the past week (January 8–14, 2023) was investigated via the websites Google Trends and Talkwalker by searching for appropriate keywords. Thanks to the analysis of related queries and topics, it was possible to determine and examine the most debated topics relating to specific side effects. Emotional reactions regarding COVID-19 vaccines have been negative in varying percentages between 40 and 70 %, depending on the topic discussed. Feelings of alarm, derision, doubt, and anger were common (about 60 %). The concerns were mainly about the effectiveness against recent COVID-19 variants and alleged side effects such as sudden death, tumors, myocarditis, prion disease, and high ferritin. The most used media among those scrutinized was Twitter (over 90 % of interactions). The male audience participated more and showed more negativity than the female one. The age groups mainly involved were the under-45s. This research discussed the combined use of Google Trends and Talkwalker to conduct rapid infoveillance surveys. The results found showed that the web public has many doubts about COVID-19 vaccines, including the appearance of very rare or unproved side effects. Based on the WHO infodemic management strategy, it is essential that this or similar approaches are adopted by health and government authorities to listen to the community and calibrate appropriate infodemiological responses aimed at preserving public health.

Can youtube be trusted as a source of quality and reliable information on COVID-19 vaccination in Italy?

On March 2022, six different search queries were used to retrieve COVID-19 vaccination-related videos, resulting in the identification of 329 videos, and their characteristics were described. Two validated instruments, namely HoNCode and DISCERN, were used to assess the reliability and quality of the videos' content. Of the total number of videos, 72.0% were from non-medical or generalist channels. The most represented category was internet media (32.5%) while the less frequent was educational medical channel (7.0%). Videos from medical channels had higher reliability (p=0.002) and quality (p<0.001) than not medical channels, despite receiving fewer visualizations (p=0.004), likes (p=0.018) and comments (p<0.001). Media and news agencies sources consistently delivered lower quality content. These findings suggest that public health professionals and institutions should consider investing in social media representation to fill the gap with non-medical sources in terms of popularity, to provide reliable and interesting videos, and ultimately deliver health education to the general public.

Rotavirus vaccination as a public health strategy to reduce the burden of hospitalization: The field experience of Italy (2008-2018).

Rotavirus (RV) infection is a leading cause of severe diarrhea among children younger than 5 years old and a considerable cause of RVgastroenteritis (RVGE) hospitalization. This study aimed to evaluate the impact of vaccination in Italy in the reduction of the burden of RV-related disease, estimating the relation between vaccination coverage and hospitalization rates.RVGE-related hospitalizations that occurred in Italy from 2008 to 2018 among children aged 0-35 months were assessed by consulting the Hospital Discharge Record database and including records whose ICD-9-CM diagnosis code was 008.61 in the first or in any diagnosis position.In the 2008-2018 period, a total of 17 535 791 at-risk person-years were considered and 74 211 (423.2 cases × 100 000 per year) RVGE hospitalizations were observed. Higher hospitalization rates occurred in males (456.6 vs. 387.9 × 100 000 per year) and in children aged 1 year (507.8 × 100 000 per year). Poisson regression analysis showed a decrease of -1.25% in hospitalization rates (-1.19% to -1.31%, p < 0.001) per unit increase in vaccination coverage.This is the first study that correlates hospitalization rate reduction with a percentage increase in vaccination coverage. Our findings strongly support RV vaccination as an effective public health strategy for reducing RVGE-related hospitalizations.

The Impact of Rotavirus Vaccination on Discharges for Pediatric Gastroenteritis in Italy: An Eleven Year (2009-2019) Nationwide Analysis.

In Italy, despite the documented positive effects of rotavirus (RV) vaccination on reducing the burden of RV disease, an updated national assessment of its impact on clinical outcomes is still lacking. This study aims to analyze the implementation of RV vaccination in Italy, evaluating its impact on discharges for acute pediatric gastroenteritis (AGE). A retrospective analysis, including hospital discharge records and data on vaccination coverage for children aged 0-71 months from 2009 to 2019, was conducted. We examined trends in hospital discharge standardized incidence before and after vaccine introduction using a negative binomial mixture model with fixed effects to evaluate the impact of universal vaccination. The percentage of vaccination coverage increased over the years, from <5% between 2009 and 2013 to 26% in 2017, reaching 70% in 2019. The standardized incidence of discharges decreased over the period from 16.6/100,000 inhabitants in 2009-2013 to 9.9/100,000 inhabitants in 2018-2019. In this phase, about 15% of the estimated hospital discharges were avoided compared with those estimated in the first phase. The implementation of RV vaccination reduced AGE incidence discharges in children aged 0-71 months. Further efforts are needed to continue monitoring the vaccination effect over time and to increase vaccination coverage.

Pneumococcal vaccination status among cirrhotic patients in Italy: a neglected topic.

To date, few reports have evaluated the pneumococcal vaccination status in cirrhotic patients. No data are available for European countries. We have explored this topic and the potential independent predictors motivating lack of vaccination in Italy. Between January 1st and June 30th 2022, 1419 cirrhotic patients of any etiology were consecutively enrolled in an observational, prospective study at 8 referral centers in Italy. Adjusted odds ratios (ORs) for the association with lack of vaccination were evaluated by multiple logistic regression analysis. Overall vaccine coverage was 17.9% (8.9% in patients < 65 years of age and 27.1% in those aged ≥ 65 years; p < 0.001). Among the 1165 unvaccinated patients, 1068 (91.7%) reported lack of information regarding vaccination as the reason for not having undergone vaccination. Independent predictors associated with lack of vaccination were age < 65 years (OR 3.39, CI 95% 2.41-4.76) and a higher number of schooling years (OR 2.14, CI 95% 1.58-2.91); alcoholic etiology resulted only marginally associated (OR 1.91, CI 95% 1.03-3.52). These findings establish evidence on how pneumococcal vaccination status in Italy is largely suboptimal among cirrhotic patients. These results raise concern, considering the severe outcomes of pneumococcal infection in patients with chronic liver diseases.

Lexicon-based sentiment analysis to detect opinions and attitude towards COVID-19 vaccines on Twitter in Italy

The paper proposes a methodology based on Natural Language Processing (NLP) and Sentiment Analysis (SA) to get insights into sentiments and opinions toward COVID-19 vaccination in Italy. The studied dataset consists of vaccine-related tweets published in Italy from January 2021 to February 2022. In the considered period, 353,217 tweets have been analyzed, obtained after filtering 1,602,940 tweets with the word “vaccin”. A main novelty of the approach is the categorization of opinion holders in four classes, Common users, Media, Medicine, Politics, obtained by applying NLP tools, enhanced with large-scale domain-specific lexicons, on the short bios published by users themselves. Feature-based sentiment analysis is enriched with an Italian sentiment lexicon containing polarized words, expressing semantic orientation, and intensive words which give cues to identify the tone of voice of each user category. The results of the analysis highlighted an overall negative sentiment along all the considered periods, especially for the Common users, and a different attitude of opinion holders towards specific important events, such as deaths after vaccination, occurring in some days of the examined 14 months.

Sero-Epidemiological Study of Varicella in the Italian General Population.

The aim of this study was to analyze the seroprevalence of varicella in Italy and to evaluate the impact of varicella vaccination, which has been mandatory for newborns since 2017. The levels of VZV-specific IgG antibodies were determined by the ELISA method in residual serum samples obtained from subjects aged between 6 and 64 years and residing in 13 Italian regions. Overall, 3746 serum samples were collected in the years 2019 and 2020. The overall seroprevalence was 91.6% (89.9% in males and 93.3% in females; p = 0.0002). Seroprevalence showed an increasing trend (p < 0.0001) starting in the younger age groups: 6-9 years: 84.1%; 10-14 years: 88.7%; 15-19 years: 89.3%; 20-39 years: 93.1% and >40 years: 97.0%. The seroprevalence data obtained in the present study were compared with those relating to previous sero-epidemiological surveys conducted, respectively, in the years 1996-1997, 2003-2004 and 2013-2014, taking into consideration only data from regions monitored in all surveillance campaigns. The comparison highlighted for the period 2019-2020 showed significantly higher values in the age groups 6-9 (p < 0.001), 10-14 (p = 0.018) and 15-19 years (p = 0.035), while in adults, the trend did not change over time (ns). These results highlight the positive impact of varicella vaccination in Italy.

Improving the distribution of covid-19 vaccines using the blockchain technology: the Italian case study

Vaccination is one of the most effective ways to prevent and control the outbreak of infectious diseases. The vaccine supply chain differs from the traditional supply chains because of the perishability of the products, which need strict transport and warehousing conditions to guarantee the health and safety of people. In addition, in case of pandemics, the big amount of doses requested for the implementation of a mass vaccination campaign forces governments to design a proper logistic network and plan a rapid and efficient distribution of vaccines. This paper studies the organization of allocation and distribution of the covid-19 vaccines in Italy. The main criticalities in managing the vaccine supply chain have been identified and, because of its peculiarities, the blockchain has been considered a suitable technology to solve them. A simulation model has been developed to reproduce the current distribution of vaccines in Italy, and a future scenario with blockchain has been studied. The findings show that it is possible to improve the performance of the vaccine supply chain and make it more resilient by implementing the blockchain technology.

COVID-19 conspiracy beliefs and vaccinations: A conceptual replication study in Turkey

Pivetti et al. (2021a; 2021b) examined links between COVID-related conspiracy beliefs and acceptance of vaccinations in Italy and Finland in 2020. They found that moral purity negatively predicted confidence in science, whereas political orientation predicted COVID-related conspiracy beliefs. Confidence in science, general conspiracy beliefs, and COVID-related conspiracy beliefs were found to negatively predict support for governmental restrictions and attitudes towards vaccines, and positively predict perceptions of informational contamination. Finally, attitudes towards vaccines in general strongly predicted attitudes towards the COVID-19 vaccine. The current research seeks to replicate these findings conceptually on a predominately Muslim sample (N = 570, M age = 26.69, 69.8% females) in Turkey in 2021, when the COVID vaccines were widely available. Measures of religiosity and left, center, and right political orientations were added to the original instrument. Hypothesized serial mediational models were tested using structural equation modelling. Results revealed that left and center political orientations positively predicted COVID-related conspiracy beliefs and confidence in science. Religiosity was negatively related to confidence in science. Confidence in science and COVID-related conspiracy beliefs predicted general attitudes toward vaccines. Conspiracy beliefs predicted COVID-related conspiracy beliefs, which in turn negatively predicted support for government restrictions and positively predicted distrust in mainstream media. Attitudes towards vaccines were strongly and positively related to attitudes toward COVID-19 vaccines. [This paper was added to the Special Issue on “Conspiracy Theories about Infectious Diseases” in a post-hoc manner. Online publishing allows the addition of new papers to a published special issue, thereby permitting a special issue to grow.]

Covid-19 vaccines in Italian public opinion: Identifying key issues using Twitter and Natural Language Processing.

The COVID-19 pandemic has changed society and people's lives. The vaccination campaign started December 27th 2020 in Italy, together with most countries in the European Union. Social media platforms can offer relevant information about how citizens have experienced and perceived the availability of vaccines and the start of the vaccination campaign. This study aims to use machine learning methods to extract sentiments and topics relating to COVID-19 vaccination from Twitter. Between February and May 2021, we collected over 71,000 tweets containing vaccines-related keywords from Italian Twitter users. To get the dominant sentiment throughout the Italian population, spatial and temporal sentiment analysis was performed using VADER, highlighting sentiment fluctuations strongly influenced by news of vaccines' side effects. Additionally, we investigated the opinions of Italians with respect to different vaccine brands. As a result, 'Oxford-AstraZeneca' vaccine was the least appreciated among people. The application of the Dynamic Latent Dirichlet Allocation (DLDA) model revealed three fundamental topics, which remained stable over time: vaccination plan info, usefulness of vaccinating and concerns about vaccines (risks, side effects and safety). To the best of our current knowledge, this one the first study on Twitter to identify opinions about COVID-19 vaccination in Italy and their progression over the first months of the vaccination campaign. Our results can help policymakers and research communities track public attitudes towards COVID-19 vaccines and help them make decisions to promote the vaccination campaign.

Real life hexavalent vaccination among children as a practical guide for public health professionals: Four years (from 2016 to 2019) of clinical practice in Sicily, Italy

ABSTRACT Hexavalent (HV) vaccination is a priority for newborn protection and in Italy is included in the National Immunization Plan with a three doses cycle at 61, 121 and 301 days of age. A retrospective clinical study has been conducted to evaluate real life clinical practice of HV vaccination in the fourth most populous Italian Region. Data on the completion of the HV cycle, on the interchangeability between the two HV adopted in 2016–2017 (DTaP3-IPV-HB/Hib) and 2018–2019 (DTaP5-IPV-HB-Hib) and on the use above the established age, were collected in five Sicilian Local Health Authorities. Data showed an average 91.5% completion of the vaccination cycle at 24 months of age. The average age of administration was significantly higher in children who switched between the two hexavalent vaccines compared to those who completed the vaccination cycle with the same product (p-value <.01). Interchangeability with one or two doses of HV was also documented in 17.8% (2018) and 16% (2019) of vaccinated infants. Co-administration with other vaccines included in the Sicilian Vaccination Schedule was 85% with anti-pneumococcal vaccination and 65% with anti-rotavirus vaccination. Children vaccinated above recommended age (from 15 to >36 months) significantly after the introduction of mandatory vaccination in Italy (p-value <.001). This retrospective analysis will contribute to manage potential disruptions due to missed routine immunization opportunities, as the pandemic has caused, with strategies such as catch up above recommended age as well as interchangeability. Data could also help to demonstrate the need to optimize vaccine sessions through co-administration, that strongly contribute to increase vaccination coverage rates and respect of timing of vaccination schedules.

Can YouTube be used as a credible source of information for COVID-19 vaccination in Italy?

Abstract Background The COVID-19 pandemic led to an ‘infodemic', as defined by the WHO, which made it difficult to be accurately informed on public health topics. For this purpose, many people use social media as a source of information, mainly YouTube. Given the great resonance of this platform, our study aims at assessing quality and reliability of its content regarding the COVID-19 vaccination. Methods During March 2022, six searches were performed on the Italian YouTube platform using the following terms: “Covid vaccination”, “Covid vaccine”, “Coronavirus vaccination”, “Coronavirus vaccine”, “Sars-Cov-2 vaccination” and “Sars-Cov-2 vaccine”. A total of 329 videos were analysed, after removing 271 duplicated videos, and classified in seven types of channel. The reliability of the content was evaluated through the HoNCode score, while quality was tested using the validated DISCERN tool. Results The most frequent category was ‘Internet Media’ (33%), while the less frequent one was ‘Educational Medical’ (7%). The content reliability (i.e. HoNCode score) resulted higher for videos produced by medical healthcare workers than non-medical ones. Concerning the quality, the DISCERN score resulted significantly higher for the Educational channels (median 46.0 for medical and 41.3 non-medical ones) as compared to Internet Media (26.5) and New Agencies (24.3). Conclusions Although YouTube has implemented a policy against misinformation related to the COVID-19 vaccination, the study highlights that there is extreme heterogeneity in reliability and quality of videos. Content produced by non-medical users, especially “Internet Media” and “News Agencies” categories should be evaluated with attention by users, as their quality is not appropriate to the importance of the topic. Key messages • Because of to the heterogeneity of its content, YouTube should be evaluated carefully when used as a source of information for Covid-19 vaccination. • Content produced by non-medical users, is generally of poor quality, not appropriate to the importance of the topic.