Clinical trial NCT04756817: Immunogenicity of the BNT162b2 Covid-19 Vaccine in Elderly People Aged 85 and Older in Greece
Official title: Immunogenicity of the BNT162b2 mRNA Covid-19 Vaccine in Elderly People Over 85 Years of Age: Real World Data From Greece
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Immunogenicity, Vaccine
Lead sponsor: G.Gennimatas General Hospital
Sponsor class: OTHER
Collaborators: name: Aristotle University Of Thessaloniki
First posted: 2021-02-16
Enrollment: 297
Sex: ALL
Minimum age (years): 85
Maximum age (years): 100
Standard ages: OLDER_ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Elderly aged 85 or older prioritised for vaccination based on the greek national vaccination plan

Brief summary: Real-world evidence confirming the effectiveness and safety of the new COVID-19 vaccines among the elderly is currently lacking. However, scarce (sparse) data derived from phase II/III trials attest to a weaker humoral immune response generated post-immunization among seniors, in contrast to younger adults. According to the national priority vaccination scheme the age group of 85 and older was the first to receive the BNT162b2 mRNA Covid-19 vaccine in Greece. The aim of the study is to enhance our insight into the humoral immunity and antibody generation elicited by the BNT162b2 mRNA Covid-19 vaccine among the elderly. The study population will include people aged 85 or older who are either uninfected or have a positive history of PCR-confirmed SARS-CoV-2 infection occurring one to 4.5 months prior to vaccination. Upon receipt of informed consent, a cohort of persons vaccinated in the two vaccination centers of the "G. Gennimatas" General Hospital of Thessaloniki will be followed over a period of six months post-injection of the second dose. To monitor the immunogenicity of the BNT162b2 mRNA Covid-19 vaccine, the SARS-CoV-2 IgG II Quant assay will be applied to conduct both 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, day 21 after the second dose and within 3 and 6 months after the second dose.

Detailed description: Real world data regarding the effectiveness and safety of the new COVID-19 vaccines in older people are currently lacking. The sparse data from Phase II/II trials suggest a reduction in antibody responses in older people compared to younger participants. 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 is to enhance insight into the immunity and antibody generation elicited by the BNT162b2 mRNA Covid-19 vaccine among elderly people over age 85. The study population will include both uninfected vaccinated persons and persons with PCR-confirmed previous SARS-CoV-2 infection occurring one to 4.5 months prior to vaccination. After informed consent a cohort of persons vaccinated in the two vaccination centers of the "G. Gennimatas" General Hospital of Thessaloniki will be followed for six months post-second dose injection. The immunogenicity of the vaccine will be 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, day 21 after the second dose and within 3 and 6 months after the second dose.

Having set the positivity threshold of the immunoassay (50 AU/ml) as a cut-off point, participants will be classified both by history of infection with SARS-CoV-2 and by SARSCoV-2 IgG II Quant assay outcomes. Subsequently, the IgG geometric mean concentration (GMC) and its 95% Confidence Interval will be calculated, based on the recorded antibody concentration values. Regarding the reactogenicity of the vaccine, on the day of blood collection the participants will be asked to report their experienced side effects. Of note, participants are asked to officially report all unsolicited adverse drug reactions (ADRs) to the National Medicines Organization via the Yellow Card scheme. The study protocol has been endorsed and ethical approval was obtained by the ethics committee of the scientific council of the "G. Gennimatas" General Hospital (protocol number:2/12.02.2021).

Regarding the reactogenicity of the vaccine, on the day of blood collection the participants will be asked to report their experienced side effects. Of note, participants are asked to officially report all unsolicited adverse drug reactions (ADRs) to the National Medicines Organization via the Yellow Card scheme.

The study protocol was approved and ethical approval was obtained by the ethics committee of the scientific council of the "G. Gennimatas" General Hospital (protocol number:2/12.02.2021).

Eligibility criteria: Inclusion Criteria:

1. Age of 85 or older
2. Without previously known SARS-CoV-2 infection, or
3. With previous PCR-confirmed SARS-CoV-2 infection one to 4.5 months prior to vaccination

Exclusion Criteria:

* Occurence of any other vaccination 4 weeks prior to enrollment
* Participation in any other clinical trial

Primary outcomes:
measure: Immunogenicity after the first dose of the BNT162b2 mRNA Covid-19 vaccine
timeFrame: 21 days after the first dose
measure: Immunogenicity after the second dose of the BNT162b2 mRNA Covid-19 vaccine
timeFrame: 21 days after the second dose
measure: Immunogenicity after the second dose of the BNT162b2 mRNA Covid-19
timeFrame: 3 months after the second dose
measure: Immunogenicity after the second dose of the BNT162b2 mRNA Covid-19
timeFrame: 6 months after the second dose
Secondary outcomes:
measure: PCR-confirmed cases of SARS-CoV-2 infection anytime after the first dose.
timeFrame: 6 months after the second dose
Other outcomes:
Locations:
city: Thessaloníki
country: Greece
facility: G. Gennimatas General Hospital
state: Thessaloniki
Study officials:
affiliation: School of Medicine,Aristotle University of Thessaloniki
name: Georgios Papazisis, As.Professor
role: STUDY_CHAIR
References:
citation: Kontopoulou K, Nakas CT, Ainatzoglou A, Ifantidou A, Ntotsi P, Katsioulis C, Papazisis G. Immunogenicity of the BNT162b2 mRNA Covid-19 vaccine in elderly people over 85 years of age in Greece: the GREVAXIMO study. Aging Clin Exp Res. 2021 Dec;33(12):3385-3389. doi: 10.1007/s40520-021-01997-7. Epub 2021 Oct 11.