NCT05160766

Assessing Immune Response of Different COVID-19 Vaccines in Older Adults

A Multinational, Phase 2, Randomised, Adaptive Protocol to Evaluate Immunogenicity and Reactogenicity of Different COVID-19 Vaccines Administration in Older Adults (≥75) Already Vaccinated Against SARS-COV-2 (EU-COVAT-1_AGED)

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 323 (actual)
• Sponsor: Oliver Cornely, MD · Academic / Other
• Sex: All
• Age: 75 Years
• Healthy volunteers: Accepted

Summary

This is a randomised controlled, adaptive, multicentre Phase II protocol evaluating different booster strategies in individuals aged 75 years and older already vaccinated against SARS-CoV-2. Part A of this trial foresees testing of different vaccines as a 3rd vaccination dose (first booster) for comparative assessment of their immunogenicity and safety against SARS-CoV-2 wild-type and variants in the elderly, a usually neglected population. Part B of this trial foresees testing of different vaccines as a 4th vaccination dose (second booster) for comparative assessment of their immunogenicity and safety against SARSCoV-2 wild-type and variants in the identical population.

Detailed description

Part A of the present trial in which individuals received a 3rd vaccination (first booster) of either BNT162b2 or mRNA-1273 was closed to further recruitment as of January 13, 2022. This was due to a change in vaccination policies, recommending a 3rd vaccination with either BNT162b2 or mRNA-1273. Therefore, Part A was supplanted by Part B that investigated a 4th COVID-19 vaccination and started on 21 Jan 2022. The initial study protocol started the trial with Part A in which participants were randomized to a 3rd vaccination (first booster) with either BNT162b2 or mRNA-1273: Subjects who - prior to study entry - received a vaccination series of either BNT162b2 \& BNT162b2 or mRNA-1273 \& mRNA-1273 or ChAdOx-1-S \& ChAdOx-1-S. For the reasons mentioned above, the study protocol was amended to continue the trial with Part B in which participants were randomized to a 4th vaccination (second booster) with either BNT162b2 or mRNA-1273: Subjects who - prior to study entry - received a vaccination series of either BNT162b2 \& BNT162b2 \& BNT162b2 or BNT162b2 \& BNT162b2 \& mRNA-1273 or mRNA-1273 \& mRNA-1273 \& mRNA-1273 or mRNA-1273 \& mRNA-1273 \& BNT162b2 or ChAdOx-1-S \& ChAdOx-1-S \& BNT162b2 or ChAdOx-1-S \& ChAdOx-1-S \& mRNA-1273.

Conditions

• Prevention of COVID-19

Interventions

Type	Name	Description
BIOLOGICAL	Comirnaty (BTN162b2)	Single booster shot (3rd dose in Part A and 4th dose in Part B)
BIOLOGICAL	Spikevax (mRNA-1273)	Single booster shot (3rd dose in Part A and 4th dose in Part B)

Timeline

• Start date: 2021-11-08
• Primary completion: 2022-10-01
• Completion: 2023-09-13
• First posted: 2021-12-16
• Last updated: 2025-05-20
• Results posted: 2025-05-20

Locations

9 sites across 4 countries: Germany, Lithuania, Norway, Spain