Real-World Trends in SARS-CoV-2 Antibody Levels

This technical report assesses the levels of SARS-CoV-2 antibodies over time in a real-world setting and examines the association between these antibody levels and subsequent COVID-19 outcomes. The study utilizes data from the Elecsys Anti-SARS-CoV-2 S assay, which quantifies antibodies in human serum and plasma, and links antibody data with infection and vaccination records from a claims repository. The analysis includes 268,844 individuals tested between April 2021 and June 2022. Results indicate that overall antibody levels increased significantly during the study period. The findings reveal that vaccinated individuals without prior infections exhibited higher median antibody titers compared to those with prior natural infections. The report concludes that higher antibody levels correlate with a reduced risk of developing symptomatic and severe COVID-19 outcomes, suggesting the relevance of monitoring SARS-CoV-2 antibody levels as a surveillance tool during the pandemic and beyond.