Brief Summary

Age is the main risk factor associated with the severity of COVID-19. From the beginning of the vaccination campaign, elderly subjects are part of the priority population. However, immunosenescence appears to play a role in the natural post-COVID-19 immunity of convalescent elderly subjects and also in the post-vaccination response. However, vaccination recommendations for both naïve (2 doses of vaccine) and convalescent subjects (1 dose of vaccine) do not differ according to age. To date, there is little data to suggest that the response to the vaccine in naïve or convalescent subjects may vary according to age in terms of qualitative and quantitative response and duration.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for phase_4 covid19

Timeline

Completed

Started Oct 2021

Typical duration for phase_4 covid19

Geographic Reach

1 country

2 active sites

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

1.4 years study duration

First Submitted

Initial submission to the registry

September 14, 2021

Completed

3 days until next milestone

First Posted

Study publicly available on registry

September 17, 2021

Completed

18 days until next milestone

Study Start

First participant enrolled

October 5, 2021

Completed

11 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 29, 2022

Completed

6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

February 28, 2023

Completed

Last Updated

December 11, 2024

Status Verified

June 1, 2023

Enrollment Period

11 months

First QC Date

September 14, 2021

Last Update Submit

December 6, 2024

Conditions

Covid19

Keywords

ImmunogenicityreactogenicitymRNA COVID-19 vaccineCOVID-19 natural immunityage

Outcome Measures

Primary Outcomes (1)

Anti-S neutralizing antibody titer
The neutralizing antibody titer against protein S from the majority variants at the time of sampling and vaccine S will be evaluated in viral neutralization and pseudoneutralization
Days : 15, 90, 180 after each dose of vaccine

Secondary Outcomes (9)

Kinetic of Anti-S antibody titer
Days : 15, 90, 180 after each dose of vaccine
Kinetic of Anti-N antibody titer
Days : 15, 90, 180 after each dose of vaccine
Kinetic of Anti-SARS-CoV-2 immunoglobulin A (IgA) titers in saliva
Days : 15, 90, 180 after each dose of vaccine
Kinetic of SARS-CoV-2 quantiferon value
Days : 15, 90, 180 after each dose of vaccine
CD4 and CD8 lymphocyte polarization specific to the vaccine S protein
Days : 15 (group Naive and convalescent), 180 (group Boost only) after last dose of vaccine
+4 more secondary outcomes

Study Arms (5)

convalescent participants PFIZER

EXPERIMENTAL

Participants with prior history of COVID-19 in ≥3 months, virologically confirmed and vaccinated by anti-covid19 Pfizer vaccine

Biological: COVID-19 vaccine Pfizer (2 doses)

Naive participants PFIZER

EXPERIMENTAL

Participant without past history of COVID-19 and vaccinated by anti-covid19 Pfizer vaccine

Biological: COVID-19 vaccine Pfizer (3 doses)

convalescent participants MODERNA

EXPERIMENTAL

Participants with prior history of COVID-19 in ≥3 months, virologically confirmed and vaccinated by anti-covid19 Moderna vaccine

Biological: COVID-19 mRNA Vaccine Moderna (2 doses)

Naive participants MODERNA

EXPERIMENTAL

Participant without past history of COVID-19 and vaccinated by anti-covid19 Moderna vaccine

Biological: COVID-19 mRNA Vaccine Moderna (3 doses)

Boost only

EXPERIMENTAL

Participant without past history of COVID-19 and vaccinated by anti-covid19 mRNA vaccine.

Biological: COVID-19 mRNA Vaccine Moderna (1 dose)