Observational study of healthcare workers' immunity to COVID-19

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

Euresist Network GEIE · NCT05534009

This study looks at how long and how well healthcare workers' immunity to COVID-19 lasts after vaccination or infection, while also checking if new virus variants can dodge that immunity.

Quick facts

Study typeObservational
Enrollment1800 (estimated)
Ages18 Years and up
SexAll
SponsorEuresist Network GEIE (other)
Locations7 sites (Düsseldorf and 6 other locations)
Trial IDNCT05534009 on ClinicalTrials.gov

What this trial studies

The EuCARE-HCW study is an observational multicentre project that collects both retrospective and prospective data from healthcare workers who have either been vaccinated against COVID-19 or have had a confirmed SARS-CoV-2 infection. Participants will provide biological samples periodically over 12-24 months to analyze the impact of different viral variants on immunity. The study aims to understand the duration and breadth of immunity following vaccination and natural infection, as well as the potential for vaccine escape by various SARS-CoV-2 variants. This research involves collaboration across eight countries, enhancing the diversity of data collected.

Who should consider this trial

Good fit: Ideal candidates for this study are adult healthcare workers over 18 years old with documented vaccination or SARS-CoV-2 infection status.

Not a fit: Patients who do not work in healthcare or do not have a history of vaccination or SARS-CoV-2 infection may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide valuable insights into the effectiveness of COVID-19 vaccines and natural immunity, potentially guiding future vaccination strategies.

How similar studies have performed: Other studies have shown success in analyzing immunity to COVID-19 variants, making this approach both relevant and necessary.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Düsseldorf and 6 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: COVID-19

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.