COVID-19 Pandemic
Demographic characteristics associated with SARS-CoV-2 antibody trajectories, February 2021 to January 2023 Ashley Judge* Ashley Judge Judge Judge Judge Judge Judge Judge Indiana University- Bloomington
Background: Antibody trajectories after SARS-CoV-2 infection provide information on immune response to natural infection [i.e. Anti-Nucleocapsid proteins (Anti-N)] and both natural infection and vaccination [i.e. Anti-Receptor Binding Domain proteins (Anti-RBD)]. Information on differences in antibody trajectories after incident SARS-CoV-2 infection among demographic subgroups may inform potential targets for future public health interventions.
Methods: We used data from a prospective cohort study of ~2,100 US adults collected between February 2021 to January 2023 to compare trajectories of anti-N antibodies (measured in ln(1+ AUC) values) after incident infection by age group, sex, race/ethnicity, income, and essential worker status. For each demographic factor, we employed separate linear mixed-effect models with random subject-specific intercepts and an interaction term between the factor and time after infection, modelled with a natural cubic spline with four degrees of freedom. We estimated peaks in trajectories by locating the maximum estimated marginal mean of antibody values during the first 90 days after infection. We performed unadjusted pairwise comparisons of the predicted peak values for each demographic group. We restricted analyses to individuals vaccinated and without prior infection to assess whether these factors influenced conclusions.
Results: Among 430 individuals with an incident infection and complete data and among correctly identified peaks, there were no statistically significant differences in the magnitude of anti-N peaks by demographic factors. Among 402 vaccinated and among 324 without prior infection, conclusions remained consistent.
Conclusion: Initial immune response to natural infection appears to be robust in magnitude across a range of social and biological factors. Future work will refine methods to identify and model anti-RBD peaks and may assess whether there exist differences in peak timing.
