Evaluation of the Effectiveness and Safety of the BNT162b2 COVID-19 Vaccine in the Vaccination Campaign Among the Health Workers of Fondazione Policlinico Universitario Agostino Gemelli IRCCS

On 11 March 2020, the rapidly spreading novel coronavirus outbreak was declared a pandemic by the World Health Organization (WHO). From that moment on, SARS-CoV-2 has affected hundreds of millions of people globally. As of 24 September 2021, as reported by the WHO, there have been 230,418,451 confirmed cases of COVID-19, including 4,724,876 deaths, worldwide. To date, the scientists reported that COVID-19 pandemic had a substantial burden of disease worldwide.

As an action to curb the burden of COVID-19, Italy authorized the marketing of Pfizer-BioNTech (BNT162b2) vaccine and licensed it for use after it showed high effectiveness and safety against symptomatic infection in a large multinational clinical trial. BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. In December 2020, Italy, jointly with other European countries, started the COVID-19 mass vaccination campaign, initially addressed to health workers, staff, and patients of homes for elderly people. Health workers, especially those in patient-facing roles, had a significantly increased risk of COVID-19 infection, having serious outcomes, and risking spreading the virus to patients and staff . Therefore, health workers have been prioritized to receive COVID-19 vaccines in many countries. By the end of March 2021, in the majority of the Italian hospitals, most health workers received both doses of the BNT162b2 COVID-19 vaccine, while few received both doses of mRNA-1273 (i.e., Moderna). In Italy, as of 25 September 2021, a total of 83,662,989 vaccine doses were administered, vaccinating 77.4% of the population aged over 12. As highlighted by the WHO , COVID-19 vaccines have been proven as safe, effective, and life-saving against this severe disease in several large vaccine trials. Several studies have been conducted to assess the effectiveness of vaccination campaigns in the health care workers in real-world settings. We add to this evidence by providing an assessment of the effectiveness and safety of (BNT162b2) vaccine among the health workers of Fondazione Policlinico Universitario Agostino Gemelli IRCCS (FPG), a large teaching hospital in Rome (Italy).

A retrospective cohort study among health staff working at the FPG will be conducted to evaluate the effectiveness and safety of BNT162b2 vaccine during the first phase of the vaccination campaign against SARS-CoV-2.

Healthcare workers (aged ≥18 years) working at hospital sites who could provide written informed consent and who will complete the immunization program with the administration of the second dose after approximately 21 days from the first dose at the FPG will be included.

Participants will be assigned into either the cohort of vaccinated or the cohort of unvaccinated health workers at the beginning of the follow-up period.