Health Care Workers Cohort Study in the EuCARE Project (EuCARE-HCW)

September 15, 2025 updated by: Euresist Network GEIE
The WP3 healthcare workers cohort in EuCARE is an observational multicentre study including collection of retrospective (historical) and prospective data and sample collection from health care workers with either a vaccination or a confirmed SARS-CoV-2 infection. Samples from HCW are sent to central laboratories for WP2 study were the impact of different variants in humoral and cellular immunity is to be analysed by biostatistical methods and with artificial intelligence in WP5. This analysis will focus on the impact on vaccine escape of viral variants / viral sequences as well as on any escape from any combination of natural and vaccine induced immunity. Eight countries will participate (Portugal, Italy, Germany, Lithuania, Georgia, Russia, Vietnam and Mexico).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Background: Protection from SARS-CoV-2 infection is known to occur soon after vaccination or natural disease, fading over time. Although protection from serious illness does occur, protection from infection is insufficient and the impact of each variant and of each vaccine or vaccine schedule is a matter of continuous study. Recruiting participants from countries with different vaccines and vaccine schedules is of upmost importance to analyse these relationships and breakthrough infections. Study objectives: The EuCARE-HCW study contributes with data and samples from

HCW to EuCARE-IMMUNITY study that will analyse the NtAb and CMI to different SARS- CoV-2 variants following any combination of natural infection and vaccination. Specific

objectives include:

  • to collect data and biological material from COVID-19 healthcare workers in 9 clinics from 8 countries and 3 continents.
  • Enrolment of HCW with an immunogenic event, either vaccination or infection.
  • Periodic collection of serum and whole blood every 4 months since enrolment and during 12-24 months (depending on how long immunity persists).

  • Sample preparation, storage and shipment to central EuCARE laboratories where WP2 study group will analyse natural and artificial immunity to SARS-CoV-2 variants (EuCARE-IMMUNITY), namely:

    • Analyse the magnitude, breadth and duration of immunity following natural infection and/or vaccination.
    • Define the cross-immunity among the different viral variants.
    • Analyse the immune escape in a comprehensive set of combinations of vaccines and natural infection(s).

  • To accomplish the above objectives, WP2 will test:

    • Neutralising antibodies
    • Cellular immunity
    • Viral sequences

Study Type

Observational

Enrollment (Estimated)

1800

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

For each subject baseline will be the occurrence of the first known immunization event, either natural infection or vaccination. The follow-up is planned to last 24 months with respect to this baseline.

Health CareWorkers can be enrolled in the category of:

(i) vaccination not followed by any later infection, (ii) infection followed by vaccination and (iii) vaccination followed by infection. However, infections diagnosed during the first wave of the epidemic are suitable for the analysis of natural immunity to SARS-CoV-2 because vaccination was administered several months later.

Description

Inclusion Criteria:

The study subjects will be selected based on the following inclusion criteria:

  1. Adult (>18 years) HCW with mandatory information on their SARS-CoV-2 infection and vaccination status.
  2. For those with a history of SARS-CoV-2 infection, diagnosis obtained by detection of SARS-CoV-2 RNA
  3. Having a signed informed consent when required by ethical approval

Exclusion Criteria: NONE

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Other

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Heath care workers (HCW)
Adult (>18 years) HCW with mandatory information on their SARS-CoV-2 infection and vaccination status. For those with a history of SARS-CoV-2 infection, diagnosis obtained by detection of SARS-CoV-2 RNA
Other: Follow up of the first known immunization event

The baseline for enrolment into the study is defined by the occurrence of the first known immunization event, either natural infection or vaccination. The follow-up is planned to last 24 months with respect to this baseline. In subjects with natural infection, the viral variant must be determined for each prospective case by analysis of a nasopharyngeal swab obtained as soon as possible at diagnosis. For historical cases where the variant was not determined and a contemporary nasopharyngeal swab has not been stored, the viral variant may be inferred when a specific variant was dominating the geographic area according to official records available at local health agencies. However, the variant assignment will be labelled as putative, rather than proved.

HCWs can be enrolled in the category of:

(i) vaccination not followed by any later infection, (ii) infection followed by vaccination and (iii) vaccination followed by infection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of HCW involved in the study
Time Frame: through study completion, an average of 3 years
To collect the higher possible number of data and biological materials from the HCWs of the participating Units
through study completion, an average of 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Euresist Network GEIE

Collaborators

Heinrich-Heine University, Duesseldorf
Centro Hospitalar Lisboa Ocidental
ASST Santi Paolo e Carlo
Bach Mai Hospital
Hospital Regional de Alta Especialidad "Dr. Juan Graham Casasus"
Vilnius University Hospital Santaros Klinikos
Istituto Europeo di Oncologia

Investigators

  • Study Chair: CRISTINA TOSCANO, DR, Centro Hospitalar de Lisboa Ocidental (CHLO)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2022

Primary Completion (Estimated)

December 15, 2025

Study Completion (Estimated)

December 15, 2025

Study Registration Dates

First Submitted

September 6, 2022

First Submitted That Met QC Criteria

September 6, 2022

First Posted (Actual)

September 9, 2022

Study Record Updates

Last Update Posted (Estimated)

September 19, 2025

Last Update Submitted That Met QC Criteria

September 15, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EuCARE-HCW

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The study is part of a project funded by the European Commission and the project agreement with theCommission affirms that the data and the results will be publi

IPD Sharing Time Frame

AFTER THE STUDY END NO TIME LIMIT WAS FIXED

IPD Sharing Access Criteria

REQUEST TO THE STUDY COORDINATOR OR TO THE PROJECTPARTNERS

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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