The percentage of individuals in a population who have antibodies to an infectious agent in their blood is called seroprevalence. It refers to a certain point in time in a defined group of people.
The COVID-19 prevalence study conducted by Statistics Austria in December 2021 surveyed the antibody status of the population that had not been vaccinated and was not officially known to be recovered. Statistics Austria conducted this study on behalf of the Federal Ministry of Education, Science and Research and in cooperation with the Federal Ministry of Social Affairs, Health, Care and Consumer Protection as well as the Medical University of Vienna, the Austrian Society for Paediatric and Adolescent Medicine, and the Federal Ministry of Defence.
Based on the results of the survey, the number of unreported SARS-CoV-2 infections was calculated among unvaccinated persons as well as those not officially known to be recovered.