Anti-RBD IgG dynamics following infection or vaccination

Identifying parameters influencing SARS-CoV-2 antibody dynamics post infection or vaccination is crucial for refining vaccination strategies. In a longitudinal analysis of 1340 samples from 375 healthcare workers, we characterized peak serological response and IgG half-life. Peak antibody titers post 2 vaccine doses were ∼ 20 times higher than natural infection; conversely, infected individuals had extended antibody half-life. Clinical and demographical factors such as BMI, age and smoking shaped peak response without affecting anti-RBD IgG half-life. A third mRNA vaccine dose increased peak antibody titers and prolonged half-life compared to the second dose. These findings underscore the diverse kinetics of SARS-CoV-2 antibody responses, which is influenced by immunization type/number and clinical factors.