Bnt162b2

The sample size for this study was determined based on the observation of mortality differences between various groups, akin to effective pharmacological interventions. The calculation was derived from previously reported mortality rates following the use or non-use of corticosteroids (41.3% and 24.8%, respectively) in hospitalized COVID-19 patients requiring high-flow oxygen [18 (link)]. To achieve the required power of 0.8, 126 patients were needed in each group (vaccinated and unvaccinated). Following the study’s completion, a post hoc statistical power analysis was conducted, revealing that being vaccinated (with two doses of BNT162b2 (Pfizer—BioNTech) or ChAdOx1-S (AstraZeneca) vaccines) reduces mortality in hospitalized COVID-19 patients, resulting in a statistical power of 93.3% for the vaccinated group and 96% for the subgroup vaccinated with BNT162b2.

Health care professionals from Rigshospitalet and Herlev-Gentofte University Hospital (Capital Region of Denmark) volunteered to participate in this approximately 6-months prospective longitudinal observational study to determine the dynamics of the antibody levels after SARS-CoV-2 infection and/or COVID-19 vaccination. The sample collection strategy did not interfere with the Danish COVID-19 vaccination program. Participants received either two doses of the BNT162b2 COVID-19 vaccine from Pfizer-BioNTech (BNT162b2) or the combination of one dose of the ChAdOx1-nCoV19 from Oxford/AstraZeneca followed by one dose of the BNT162b2 COVID-19 vaccines (ChAdOx1/BNT162b2). Samples were collected before or up to 14 days after the first dose and approximately 3 weeks, 2 months, and 6 months after the first dose. Age, sex, weight, and height were collected from online questionnaires completed by the participants. Venous blood samples collection fulfilled the principles described in the Declaration of Helsinki. The participants provided informed consent after oral and written information. The protocol was approved by the Regional Scientific Ethics Committee of the Capital Region of Denmark (H-20079890).

The seronegative control samples provided by the Cell Bank (BCRJ) were included in the study through the approved Ethics Committee of the Federal University of ABC (CAAE: 43139921.2.0000.5594). These control serum samples were collected from venous blood before the COVID-19 pandemic (n = 10). The ChAdOx1-S (Oxford–AstraZeneca) (n = 29) and BNT162b2 (Pfizer–BioNTech) (n = 29) venous blood were collected from vaccinated study participants who reported no previous infection with SARS-CoV-2 at least 28 days after the second immunization. Written informed consent was approved by the Ethics Committee in Research of the Clinics Hospital of the University of Sao Paulo Medical School (HC-FMUSP CAPPesq-CAAE: 30155220.3.0000.0068) and signed by all vaccinated study participants. Samples were categorized along with the article as pre-pandemic, AstraZeneca WT (serum from individuals vaccinated with ChAdOx1-S and evaluated using the spike WT protein as antigen), Pfizer WT (serum from individuals vaccinated with BNT162b2 and evaluated using the spike WT protein as antigen), AstraZeneca P.1 (serum from individuals vaccinated with ChAdOx1-S and evaluated using the spike P.1 protein as antigen), and Pfizer P.1 (serum from individuals vaccinated with BNT162b2 and evaluated using the spike P.1 protein as antigen).

Blood samples were collected at two time points from COVID‐19 patients (before vaccination with at least 4 months after confirmed diagnosis and 4 weeks after vaccination with either BNT162b2 [Pfizer] or ChAdOx1‐S [AstraZeneca]); and at three‐time points from healthy volunteers (1 day before vaccination and 4 weeks following the first and second doses of ChAdOx1‐S or BNT162b2 vaccines).

A retrospective study aimed at assessing the immune response in healthy adult volunteers (n = 195) belonging to the staff of the University-Hospital of Ferrara vaccinated with two doses of anti-SARS-CoV-2 vaccine: Pfizer–BioNTech/BNT162b2 (mRNA-based vaccine) or adenovector, ChAdOx1/AstraZeneca (AdV-based vaccine), in the period starting from January 2021, according to the directives of the Italian Health Ministry. A 6-month period from the second vaccine dose (15–190 days) was considered adequate to monitor the entire circulating antibody kinetic as recently reported by Salvagno et al. in healthcare workers (Salvagno et al., 2022b (link)). The study involving human participants was reviewed and approved by the local regional ethical committee (CE-AVEC; 405/2020/Oss/UniFe); the participants provided their written informed consent to participate in this study. The study consisted of a first immunological assessment aimed at evaluating the anti-SARS-CoV-2 circulating antibodies (IgG and neutralizing antibodies, NAbs) and a genotyping profile investigation including a group of selected common gene variants to identify candidate genetic modifiers of the vaccine-induced immune response.