Integrated Antibody and DIA–Based Plasma Proteomics Uncover Temporal Host Responses to SARS–CoV–2 Infection

This is a single–case longitudinal study in which we monitored antibody responses and plasma proteome dynamics over a 310–day period in a single individual who underwent COVID–19 vaccination and SARS–CoV–2 infection. To evaluate COVID–19 antibody responses, human plasma samples collected over 310 days (August 18, 2021, to June 22, 2022) were analyzed by DIA–LC–MS/MS proteomics. This led to the acquisition of a quantitative protein profile and allowed validation of the temporal behavior of expressed proteins within the samples. A total of 1,502 proteins were identified from the plasma samples. Before vaccination, after the first dose, after the second dose, and during the period after contracting the novel coronavirus, protein quantification values during each event interval were compared. Despite minimal changes before and after COVID–19 vaccination, notable proteins exhibiting distinct high–expression and low–expression patterns were identified after SARS–CoV–2 infection.