Active Surveillance of Adverse Events in Healthcare Workers Recipients After Vaccination with COVID-19 BNT162b2 Vaccine (Pfizer-BioNTech, Comirnaty): A Cross-Sectional Study

Abstract

In this cross-sectional study, adverse events after the first and second dose of BNT162b2 mRNA (Pfizer-BioNTech, Comirnaty) vaccine against coronavirus disease 2019 were investigated among employees of clinics in central Italy. A 42-items questionnaire was administrated to vaccine recipients. Adverse events were classified based on severity and occurrence as reported in the literature. A descriptive/univariate analysis using Chi-square or Fisher’s Exact tests was performed. Odds ratio (OR) and 95% confidence intervals were calculated to assess risk factors. 340 individuals (61.5% females; median age 49 years) participated. Adverse events were reported by 279 (82%) and 281 (82.6%) individuals as induced by the first and second dose, respectively. Mild reactions were mainly reported (80.9% and 80.3%), followed by moderate (11.8% and 37.1%) and severe (3.8% and 4.7%). Adverse events were identical to those already described as very common (81.8% and 80.6%), although vaccine-coincidental events not cited in the literature were reported by 6% and 15.6% following each dose. Age ≤ 55 years was a risk factor for any adverse event after each injection (ORs: 2.942 and 2.818), as well as female sex for those mild (ORs: 1.856 and 2.818) and common (ORs: 3.452 and 2.145). Findings were consistent with national reports as most of the adverse events were mild and associated with female sex and young age, while investigations are needed for reactions not described elsewhere. Data are useful to support the vaccine safety profile, also because largely targeted healthcare personnel more skilled than general population in self-diagnosis of health-related issues.

Adverse Reactions to Anti-SARS-CoV-2 Vaccine: A Prospective Cohort Study Based on an Active Surveillance System

“…Coronavirus disease 2019 (COVID-19) is a life-threatening condition [ 1 , 2 ] caused by severe acute respiratory coronavirus 2 syndrome (SARS-CoV-2) [ 1 ], being worldwide lethal in ~2% of cases [ 2 ]. To reduce its morbidity and mortality, the most efficacious prevention strategy is vaccination [ 2 ]. Healthcare workers are one of the principal targets of vaccination because of their occupational exposure [ 2 , 3 ].…”

“…To reduce its morbidity and mortality, the most efficacious prevention strategy is vaccination [ 2 ]. Healthcare workers are one of the principal targets of vaccination because of their occupational exposure [ 2 , 3 ].…”

“…Nowadays, at least 300 vaccines against SARS-CoV-2 are being experimented [ 4 ]. However, the first available to be administered in Italy was BNT162b2 (Comirnaty, Pfizer-BioNTech) [ 2 ], whose main constituent is the mRNA encoding the SARS-CoV-2 spike protein. For its pharmacological characteristics, BNT162b2 demonstrated high immunogenicity and tolerability in clinical trial studies [ 5 ].…”

COVID-19 mRNA vaccine safety, immunogenicity, and effectiveness in a hospital setting: confronting the challenge

“…both considering the general population or even HCWs [2,3]. In this regard, it is worth mentioning a cross-sectional study recently published by Ripabelli, also enrolling HCWs, found that age under 55 years was a predictor for AEFIs [7], supporting findings from Ponticelli and colleagues. Further research should explore possible factors other than age and sex, which might influence AEFIs occurrence, including health status and comorbidities.…”

“…In light of the surge of virulent variants, and the reduction of effectiveness and immunities observed in some countries [5], that are causing new epidemic waves, this commentary aims at generating further discussion and debate on the need to focus efforts in enhancing studies on long-term immunological response to and safety of COVID-19 vaccinations. Indeed, the existing body of evidence collected so far has been providing strong confirmation of short and mediumterm efficacy and safety of COVID-19 vaccines that confirmed vaccination as an essential tool for the control of the SARS-CoV-2 pandemic [1,[5][6][7][8][9]. However, questions as such as how long the protection obtained after vaccination lasts, as well as whether there are differences among age groups or sexes in vaccine effectiveness and safety, and best vaccination schedule for a life-long protection still need to be answered.…”