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In August 2022, Italy launched a vaccination campaign to combat the spread of the monkeypox virus, which the WHO has designated as a public health emergency. Priority targets for the campaign included laboratory personnel and men who have sex with men with specific risk criteria. Primary immunization involved two doses of the Imvanex/Jynneos vaccine, followed by a single booster dose. We conducted a study in two Italian towns, Bologna and Forlì, in October and November 2022 to investigate adverse events following immunization (AEFIs) of the monkeypox vaccine through participant-based active surveillance. Participants who received the vaccine and were aged 18 and over were invited to complete an e-questionnaire by scanning a QR code during their second vaccine appointment or by email one month after the booster dose. A descriptive analysis of AEFI incidences was conducted, with the results stratified by type and severity of symptoms. A total of 135 first-dose, 50 second-dose, and 6 single-dose recipients were included, with a mean age of 36.4 ± 8.7 years. Systemic reactions after the first and second doses were reported by 39.3% and 26.0% of participants, respectively, with asthenia being the most common symptom. Local site reactions were reported by 97.0% and 100.0% of participants, respectively, with redness, swelling, and itching being the most common local AEFIs. Grade 3 or 4 AEFIs were reported for local AEFIs only by 16.8% and 14.0% of participants after the first and second doses, respectively. Our findings suggest that the monkeypox vaccine has a high tolerability profile in terms of short-term common systemic AEFIs. However, the high incidence and severity of local AEFIs highlight the need to monitor their persistence following intradermal administration of the vaccine. [ABSTRACT FROM AUTHOR]

Introduction: One of the major criticisms facing the research community during SARS-CoV2 pandemic was the lack of large-scale, longitudinal data on the efficacy of the SARS-CoV2 mRNA vaccines. Currently, even if COVID-19 antiviral treatments have been authorized by European Medicine Agency, prevention through approved specific vaccines is the best approach available in order to contain the ongoing pandemic. Objectives: Here, we studied the antibody kinetic over a one-year period from vaccination with the Pfizer-BioNTech (Pfizer) vaccines and subsequent boosting with either the BioNTech or Moderna (Spikevax) vaccines in a large cohort of 8,071 healthcare workers (HCW). We also described the impact of SARS-CoV2 infection on antibody kinetic over the same period. Methods: We assessed the anti SARS-CoV2 Spike IgG antibody kinetic by the high throughput dried blood spot (DBS) collection method and the GSP®/DELFIA® Anti-SARS-CoV2 IgG assay (PerkinElmer®). Results: Our data support existing models showing that SARS-CoV2 vaccination elicits strong initial antibodies responses that decline with time but are transitorily increased by administering a vaccine booster. We also showed that using heterologous vaccine/booster combinations a stronger antibody response was elicited than utilizing a booster from the same vaccine manufacturer. Furthermore, by considering the impact of SARS-CoV2 infection occurrence in proximity to the scheduled booster administration, we confirmed that booster dose did not contribute significantly to elicit higher antibody responses. Conclusion: DBS sampling in our large population of HCWs was fundamental to collect a large number of specimens and to clarify the effective mRNA vaccine-induced antibody kinetic and the role of both heterologous boosters and SARS-CoV2 infection in modulating antibody responses. [ABSTRACT FROM AUTHOR]