Myocarditis and pericarditis following the Coronavirus Disease 2019 (COVID-19) mRNA vaccines administration have been reported, but their frequency is still uncertain in the younger population. This study investigated the association between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccines, BNT162b2, and mRNA-1273 and myocarditis/pericarditis in the population of vaccinated persons aged 12 to 39 years in Italy. We conducted a self-controlled case series study (SCCS) using national data on COVID-19 vaccination linked to emergency care/hospital discharge databases. The outcome was the first diagnosis of myocarditis/pericarditis between 27 December 2020 and 30 September 2021. Exposure risk period (0 to 21 days from the vaccination day, subdivided in 3 equal intervals) for first and second dose was compared with baseline period. The SCCS model, adapted to event-dependent exposures, was fitted using unbiased estimating equations to estimate relative incidences (RIs) and excess of cases (EC) per 100,000 vaccinated by dose, age, sex, and vaccine product. Calendar period was included as time-varying confounder in the model. During the study period 2,861,809 persons aged 12 to 39 years received mRNA vaccines (2,405,759 BNT162b2; 456,050 mRNA-1273); 441 participants developed myocarditis/pericarditis (346 BNT162b2; 95 mRNA-1273). Within the 21-day risk interval, 114 myocarditis/pericarditis events occurred, the RI was 1.99 (1.30 to 3.05) after second dose of BNT162b2 and 2.22 (1.00 to 4.91) and 2.63 (1.21 to 5.71) after first and second dose of mRNA-1273. During the [0 to 7) days risk period, an increased risk of myocarditis/pericarditis was observed after first dose of mRNA-1273, with RI of 6.55 (2.73 to 15.72), and after second dose of BNT162b2 and mRNA-1273, with RIs of 3.39 (2.02 to 5.68) and 7.59 (3.26 to 17.65). The number of EC for second dose of mRNA-1273 was 5.5 per 100,000 vaccinated (3.0 to 7.9). The highest risk was observed in males, at [0 to 7) days after first and second dose of mRNA-1273 with RI of 12.28 (4.09 to 36.83) and RI of 11.91 (3.88 to 36.53); the number of EC after the second dose of mRNA-1273 was 8.8 (4.9 to 12.9). Among those aged 12 to 17 years, the RI was of 5.74 (1.52 to 21.72) after second dose of BNT162b2; for this age group, the number of events was insufficient for estimating RIs after mRNA-1273. Among those aged 18 to 29 years, the RIs were 7.58 (2.62 to 21.94) after first dose of mRNA-1273 and 4.02 (1.81 to 8.91) and 9.58 (3.32 to 27.58) after second dose of BNT162b2 and mRNA-1273; the numbers of EC were 3.4 (1.1 to 6.0) and 8.6 (4.4 to 12.6) after first and second dose of mRNA-1273. The main study limitations were that the outcome was not validated through review of clinical records, and there was an absence of information on the length of hospitalization and, thus, the severity of the outcome. This population-based study of about 3 millions of residents in Italy suggested that mRNA vaccines were associated with myocarditis/pericarditis in the population younger than 40 years. According to our results, increased risk of myocarditis/pericarditis was associated with the second dose of BNT162b2 and both doses of mRNA-1273. The highest risks were observed in males of 12 to 39 years and in males and females 18 to 29 years vaccinated with mRNA-1273. The public health implication of these findings should be considered in the light of the proven mRNA vaccine effectiveness in preventing serious COVID-19 disease and death. Pharmacovigilance reports and observational studies have suggested an increased risk of myocarditis/pericarditis following the Coronavirus Disease 2019 (COVID-19) mRNA vaccine administration in people younger than 40 years. More information on the safety of COVID-19 mRNA vaccines is needed to further explore the relationship between mRNA vaccines and myocarditis/pericarditis in this population. We conducted a multiregional self-controlled case series (SCCS) study in Italy between 27 December 2020 to 30 September 2021 to investigate the association between myocarditis/pericarditis and COVID-19 mRNA vaccines in the population aged 12 to 39 years (n = 2,861,809). We found 441 myocarditis/pericarditis cases, 114 of which occurred within the 21-day risk interval after vaccination. Within the 21-day risk interval, the relative incidence (RI) was 1.99 (95% confidence interval [CI] 1.30 to 3.05) after the second dose of BNT162b2 and 2.22 (1.00 to 4.91) and 2.63 (1.21 to 5.71) after the first and second doses of mRNA-1273, respectively. Within the 0 to 7-day risk interval, the RI was 6.55 (2.73 to 15.72) after first dose of mRNA-1273 and 3.39 (2.02 to 5.68) and 7.59 (3.26 to 17.65) after the second doses of BNT162b2 and mRNA-1273, respectively. The highest risk was seen in males, 0 to 7 days after the first and second dose of mRNA-1273 (RIs of 12.28 (4.09 to 36.83) and 11.91 (3.88 to 36.53), respectively). After the second dose of mRNA-1273 in males, the excess of cases (EC) was 8.8 (4.9 to 12.9) per 100,000 vaccinated individuals. Consistent with previous studies, the findings suggest that COVID-19 mRNA vaccines were associated with myocarditis/pericarditis in the population younger than 40 years. The results provide information that could be helpful for the continuous assessment of the postmarketing benefit/risk profile of the COVID-19 mRNA vaccines and should be considered within the context of the proven mRNA vaccine effectiveness in reducing COVID-19 morbidity and mortality.

In southern Europe, the risk of cancer in patients with end-stage kidney disease receiving dialysis has not been well quantified. The aim of this study was to assess the overall pattern of risk for de novo malignancies (DNMs) among dialysis patients in the Friuli Venezia Giulia region, north-eastern Italy. A population-based cohort study among 3407 dialysis patients was conducted through a record linkage between local healthcare databases and the cancer registry (1998–2013). Person-years (PYs) were calculated from 30 days after the date of first dialysis to the date of DNM diagnosis, kidney transplant, death, last follow-up or December 31, 2013, whichever came first. The risk of DNM, as compared to the general population, was estimated using standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). During 10,798 PYs, 357 DNMs were diagnosed in 330 dialysis patients. A higher than expected risk of 1.3-fold was found for all DNMs combined (95% CI: 1.15–1.43). The risk was particularly high in younger dialysis patients (SIR = 1.88, 95% CI: 1.42–2.45 for age 40–59 years), and it decreased with age. Moreover, significantly increased DNM risks emerged during the first 3 years since dialysis initiation, especially within the first year (SIR = 8.52, 95% CI: 6.89–10.41). Elevated excess risks were observed for kidney (SIR = 3.18; 95% CI: 2.06–4.69), skin non-melanoma (SIR = 1.81, 95% CI: 1.46–2.22), oral cavity (SIR = 2.42, 95% CI: 1.36–4.00), and Kaposi’s sarcoma (SIR = 10.29, 95% CI: 1.25–37.16). The elevated risk for DNM herein documented suggest the need to implement a targeted approach to cancer prevention and control in dialysis patients.

Influenza and its complications are an important public health concern, and vaccination remains the most effective prevention measure. However, the efficacy of vaccination depends on several variables, including the type of strategy adopted. The goal of this study was to assess the impact of different influenza vaccination strategies in preventing hospitalizations for influenza and its related respiratory complications. A retrospective cohort study was conducted on data routinely collected by the health services for six consecutive influenza seasons, considering the population aged 65 years or more at the time of their vaccination and living in northeastern Italy. Our analysis concerns 987,266 individuals vaccinated against influenza during the study period. The sample was a mean 78.0 ± 7.7 years old, and 5681 individuals (0.58%) were hospitalized for potentially influenza-related reasons. The hospitalization rate tended to increase over the years, not-significantly peaking in the 2016–2017 flu season (0.8%). Our main findings revealed that hospitalizations related to seasonal respiratory diseases were reduced as the use of the enhanced vaccine increased (R² = 0.5234; p < 0.001). Multivariate analysis confirmed the significantly greater protective role of the enhanced vaccine over the conventional vaccination strategy, with adjusted Odds Ratio (adj OR) = 0.62 (95% CI: 0.59–0.66). A prior flu vaccination also had a protective role (adj OR: 0.752 (95% CI: 0.70–0.81)). Age, male sex, and H3N2 mismatch were directly associated with a higher risk of hospitalization for pneumonia. In the second part of our analysis, comparing MF59-adjuvanted trivalent inactivated vaccine (MF59-TIV) with conventional vaccines, we considered 479,397 individuals, of which 3176 (0.66%) were admitted to a hospital. The results show that using the former vaccine reduced the risk of hospitalization by 33% (adj OR: 0.67 (95% CI: 0.59–0.75)). This study contributes to the body of evidence of a greater efficacy of enhanced vaccines, and MF59-adjuvanted TIV in particular, over conventional vaccination strategies in the elderly.

People with a history of cancer have a higher risk of death when infected with SARS-CoV-2. COVID-19 vaccines in cancer patients proved safe and effective, even if efficacy may be lower than in the general population. In this population-based study, we compare the risk of dying of cancer patients diagnosed with COVID-19 in 2021, vaccinated or non-vaccinated against SARS-CoV-2 and residing in Friuli Venezia Giulia or in the province of Reggio Emilia. An amount of 800 deaths occurred among 6583 patients; the risk of death was more than three times higher among unvaccinated compared to vaccinated ones [HR 3.4; 95% CI 2.9–4.1]. The excess risk of death was stronger in those aged 70–79 years [HR 4.6; 95% CI 3.2–6.8], in patients with diagnosis made <1 year [HR 8.5; 95% CI 7.3–10.5] and in all cancer sites, including hematological malignancies. The study results indicate that vaccination against SARS-CoV-2 infection is a necessary tool to be included in the complex of oncological therapies aimed at reducing the risk of death.