Immunogenicity of the BNT162b2 mRNA COVID-19 Vaccine in Elderly People Over 85 Years of Age in Greece

10 Pages Posted: 11 Jun 2021

See all articles by Konstantina Kontopoulou

Konstantina Kontopoulou

G. Gennimatas General Hospital

Christos Nakas

University of Bern - University Institute of Clinical Chemistry; University of Thessaly

Alexandra Ainatzoglou

Aristotle University of Thessaloniki - Department of Clinical Pharmacology

Athina Ifantidou

G. Gennimatas General Hospital

Georgia Goudi

G. Gennimatas General Hospital

Paschalina Ntotsi

G. Gennimatas General Hospital

Antonis Baxevanidis

G. Gennimatas General Hospital

Matina Tsormpatzoglou

G. Gennimatas General Hospital

Chrysoula Belai

G. Gennimatas General Hospital

Christos Katsioulis

G. Gennimatas General Hospital

Georgios Papazisis

Aristotle University of Thessaloniki - Department of Clinical Pharmacology; Clinical Trials Unit, Special Unit for Biomedical Research and Education, School of Medicine, Aristotle University

Date Written: May 20, 2021

Abstract

Real world data regarding the effectiveness and safety of the new COVID-19 vaccines in older people are currently lacking. The over-85 age group was the first group to receive the BNT162b2 mRNA COVID-19 vaccine in Greece according to the national priority vaccination scheme. The aim of the study was to enhance insight into the antibody generation elicited by the BNT162b2 mRNA COVID-19 vaccine among elderly people over age 85. The immunogenicity was measured using the SARS-CoV-2 IgG II Quant assay to conduct a qualitative and quantitative determination of IgGs against the receptor-binding domain (RBD) of the S1 subunit of the SARS-CoV-2 spike protein on day 21 after the first dose and day 21 after the second dose. In the first phase of our study, antibody levels were monitored in a total of 400 participants while our final sample consisted of 297 subjects since 103 vaccinees did not show up for the second antibody measurement 21 days after the second dose. First dose response was accounted to 69.75% (95%CI: 65.25,74.25) of the subjects and second dose response to 98.99% (95%CI: 97.85, 100). No significance difference between gender was observed (p=0.311). Overall, an impressive 40-fold change was observed between the two doses however, values are plateauing for higher titer levels after 1st dose. Subjects with low response levels after the first dose have significantly higher changes than subjects with initially high response levels. Comorbidities did not seem to affect antibody responses, with the exception of vaccinees with heart disease in whom significantly lower antibody titers were recorded after the first dose, compared to those with a negative history. Concluding, our study highlighted the high foldchange (41.18) recorded in the titers of neutralizing antibodies after the second dose suggesting the need for its timely administration to the elderly individuals. Further studies are needed to better understand the immune response of this population and to determine the duration of the antibody response.

Note: Trial Registration: The trial is registered at ClinicalTrials.gov (Identifier: NCT04756817).

Funding Statement: This work received no specific grant from any funding agency.

Declaration of Interests: None to declare.

Ethics Approval Statement: The study protocol was reviewed and approved by the Scientific Committee of “G. Gennimatas” General Hospital (protocol number:2/12.2.2021). All subjects agreed to voluntarily participate in the study and provided written informed consent.

Keywords: BNT162b2 mRNA COVID-19 vaccine, immunogenicity, SARS-CoV-2, elderly over age 85, Greece

Suggested Citation

Kontopoulou, Konstantina and Nakas, Christos and Ainatzoglou, Alexandra and Ifantidou, Athina and Goudi, Georgia and Ntotsi, Paschalina and Baxevanidis, Antonis and Tsormpatzoglou, Matina and Belai, Chrysoula and Katsioulis, Christos and Papazisis, Georgios, Immunogenicity of the BNT162b2 mRNA COVID-19 Vaccine in Elderly People Over 85 Years of Age in Greece (May 20, 2021). Available at SSRN: https://ssrn.com/abstract=3850394 or http://dx.doi.org/10.2139/ssrn.3850394

Konstantina Kontopoulou

G. Gennimatas General Hospital ( email )

Eth. Aminis 41
Thessaloniki, 54635
Greece

Christos Nakas

University of Bern - University Institute of Clinical Chemistry ( email )

Bern
Switzerland

University of Thessaly ( email )

Gaiopolis Campus
Larissa, 41110
Greece

Alexandra Ainatzoglou

Aristotle University of Thessaloniki - Department of Clinical Pharmacology ( email )

Greece

Athina Ifantidou

G. Gennimatas General Hospital

Eth. Aminis 41
Thessaloniki, 54635
Greece

Georgia Goudi

G. Gennimatas General Hospital

Eth. Aminis 41
Thessaloniki, 54635
Greece

Paschalina Ntotsi

G. Gennimatas General Hospital

Eth. Aminis 41
Thessaloniki, 54635
Greece

Antonis Baxevanidis

G. Gennimatas General Hospital

Eth. Aminis 41
Thessaloniki, 54635
Greece

Matina Tsormpatzoglou

G. Gennimatas General Hospital ( email )

Eth. Aminis 41
Thessaloniki, 54635
Greece

Chrysoula Belai

G. Gennimatas General Hospital

Eth. Aminis 41
Thessaloniki, 54635
Greece

Christos Katsioulis

G. Gennimatas General Hospital ( email )

Eth. Aminis 41
Thessaloniki, 54635
Greece

Georgios Papazisis (Contact Author)

Aristotle University of Thessaloniki - Department of Clinical Pharmacology ( email )

Greece

Clinical Trials Unit, Special Unit for Biomedical Research and Education, School of Medicine, Aristotle University

University Campus
S. Kyriakidi 1
Thessaloniki, Thessaloniki
Greece

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Downloads
237
Abstract Views
1,207
Rank
195,295
PlumX Metrics