Abstract
Objective: To evaluate the socioeconomic patterns of SARS-CoV-2 antigen contacts through infection, vaccination or both ("hybrid immunity") after 1 year of vaccination campaign. Methods: Data were derived from the German seroepidemiological Corona Monitoring Nationwide study (RKI-SOEP-2; n = 10,448; November 2021-February 2022). Combining serological and self-report data, we estimated adjusted prevalence ratios (PR) of SARS-CoV-2 infection, COVID-19 vaccination, basic immunization (at least two SARS-CoV-2 antigen contacts through vaccination and/or infection), and three antigen contacts by education and income. Results: Low-education groups had 1.35-times (95% CI 1.01-1.82) the risk of SARS-CoV-2 infection compared to high-education groups. COVID-19 vaccination (at least one dose) and basic immunization decreased with lower education and income. Low-education and low-income groups were less likely to have had at least three antigen contacts (PR low vs. high education: 0.74, 95% CI 0.65-0.84; PR low vs. high income: 0.66, 95% CI 0.57-0.77). Conclusion: The results suggest a lower level of protection against severe COVID-19 for individuals from low and medium socioeconomic groups. Pandemic response and vaccination campaigns should address the specific needs and barriers of these groups.