Chiara Marrocu

Background: Vaccination is a highly effective tool for controlling infectious diseases, particularly in populations at high risk of contagion due to clinical conditions or occupational exposure, such as healthcare workers. The purpose of this study is to present the open day event that marked the beginning of the influenza and anti-COVID-19 vaccination campaign in the Lombardy region and to describe the experience of an Istituto di Ricovero e Cura a Carattere Scientifico in Milan. Methods: During the vaccination open day, eligible individuals received free vaccinations for influenza, COVID-19, pneumococcal disease, and shingles, as provided by the Lombardy Agenzia per la Tutela della Salute. In celebration of the centenary of the Università degli Studi di Milano, the Fondazione Ca’Granda Ospedale Policlinico, a contracted hospital of the university, created a special electronic diary for a total of 150 individuals, equally divided between children aged 2–6, pregnant women, and university staff. Results: At the regional level, a total of 6634 influenza vaccines, 2055 anti-COVID-19 vaccines, 108 anti-pneumococcal vaccines, and 37 anti-zoster vaccines were administered. A total of 3134 (47.3%) influenza vaccines, 1151 (56%) anti-COVID-19 vaccines, and 77 (62%) anti-pneumococcal vaccines, were given to individuals aged 60–79. No differences were observed between the total number of male and female vaccinees (1017 and 1038, respectively), who received the anti-COVID-19 vaccine. At the Policlinico Foundation, out of 150 available booking slots, 154 vaccines were administered, including 117 influenza vaccines. Conclusions: The establishment of vaccine open days is a beneficial way to increase vaccine compliance. Co-administration of little-known vaccinations outside of healthcare settings could also be a useful tool.

Mosquito-borne West Nile virus (WNV) infection is benign in most individuals but can cause encephalitis in <1% of infected individuals. We show that ∼35% of patients hospitalized for WNV disease (WNVD) in six independent cohorts from the EU and USA carry auto-Abs neutralizing IFN-α and/or -ω. The prevalence of these antibodies is highest in patients with encephalitis (∼40%), and that in individuals with silent WNV infection is as low as that in the general population. The odds ratios for WNVD in individuals with these auto-Abs relative to those without them in the general population range from 19.0 (95% CI 15.0–24.0, P value <10–15) for auto-Abs neutralizing only 100 pg/ml IFN-α and/or IFN-ω to 127.4 (CI 87.1–186.4, P value <10–15) for auto-Abs neutralizing both IFN-α and IFN-ω at a concentration of 10 ng/ml. These antibodies block the protective effect of IFN-α in Vero cells infected with WNV in vitro. Auto-Abs neutralizing IFN-α and/or IFN-ω underlie ∼40% of cases of WNV encephalitis.

Background: Healthcare workers (HCWs) are a historical key target of influenza vaccination programs. For the 2021–2022 season, WHO considered the coadministration of a flu and a COVID-19 vaccine as acceptable and recommended it to allow for higher uptake of both vaccines. The aim of this study was to investigate demographic and occupational features of vaccinated HCWs, reasons behind flu vaccine acceptance and a possible effect of the coadministration of a COVID-19 vaccine, in order to potentially draw general conclusions on HCWs’ attitude towards flu vaccination and inform further strategies for consistent improvement of vaccine acceptance. Methods: a promotional and educational campaign, a gaming strategy, and vaccination delivery through both a large central hub and on-site ambulatories, were the implemented strategies. In the central hub, the flu/COVID-19 vaccine coadministration was offered. Statistical descriptive analysis, multiple correspondence analysis (MCA) and logistic regression models were performed. Results: 2381 HCWs received the flu vaccine, prompting a vaccination coverage rate (VCR) of 52.0% versus 43.1% in the 2020–2021 campaign. Furthermore, 50.6% vaccinated HCWs belonged to the 18–39 years-old age group. The most expressed reasons for vaccine uptake were “Vaccination is the most effective strategy of prevention” (n = 1928, 81.0%), “As HCW it’s my duty to get vaccinated to protect my patients” (n = 766, 32.2%), and the group of COVID-19-related reasons (n = 586, 24.6%). In addition, 23.3% HCWs received the flu vaccine in the current campaign but not in the previous one (newly vaccinated) and the flu/COVID-19 vaccine coadministration was more frequent in this group. A total of 51.0% HCWs were hesitant towards the coadministration, while residents and nurses showed the highest propensity to receive it. Conclusions: in the second year of the COVID-19 pandemic, the Fondazione’s influenza VCR continued to increase, with the greatest participation among HCWs aged 18–39 years. A potential propelling role of the COVID-19 vaccine coadministration was highlighted.