Observational Study of SARS-CoV-2 Immunity in Adult Health Care Workers Collecting Data and Samples on Vaccination and Infection Across Multiple Countries

What this Trial Is About

Researchers are studying healthcare workers who have either received a COVID-19 vaccine or had a confirmed SARS-CoV-2 infection. This observational study involves multiple centers across eight countries and aims to analyze how different virus variants affect immunity from vaccination and natural infection. The focus is on understanding how virus variants may evade immune protection from vaccines or past infections by examining both antibody and cellular immunity. Participants include adult healthcare workers aged 18 and older who have known vaccination or infection history. The study follows each participant from their first immune event, either infection or vaccination, with follow-up planned for up to 24 months. Blood and serum samples are collected every four months and sent to central laboratories where advanced statistical and artificial intelligence methods analyze immune responses and viral sequences to assess protection and immune escape. Participants will provide retrospective and prospective data and biological samples over one to two years, depending on immune persistence. Researchers measure neutralizing antibodies, cellular immunity, and viral variants to understand immunity duration and effectiveness against different SARS-CoV-2 variants. The study tracks the number of healthcare workers involved through an average of three years and collects data to help define cross-immunity among variants and the impact of vaccine and natural infection combinations.

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