The Gutenberg COVID-19 (GCS) Study was a prospective cohort study based on a representative population sample from the Rheinhessen region. Participants were recruited through a random selection process conducted via the local registration offices, a total of 10,250 individuals were enrolled across several representative waves.

Two study visits took place between October 2020 and June 2021. During each visit, participants completed a detailed, interdisciplinary questionnaire on health, infection status, symptoms, psychosocial well-being, and living conditions, and submitted a stool sample collected at home. In addition, they visited the study center for a brief interview and the collection of various biological samples, including blood and throat swabs, as well as periodontal pocket swabs, tear fluid, and blood cells for immunological and genetic analyses. The Gutenberg COVID-19 app was also used, allowing volunteer participants to provide additional information at regular intervals. To track long-term developments and potential consequences, a follow-up was conducted one year after the initial examination. In this way, both the acute health status and the potential long-term effects of the pandemic and a SARS-CoV-2 infection could be systematically documented.