Cytokine Profiles in Peripheral Blood Mononuclear Cells and Neutrophils following SARS-CoV-2 Vaccination: A Study from Kuwait.

COVID-19 continues to be associated with substantial morbidity and mortality, and understanding vaccine-induced immune regulation beyond antibody responses remains important. This study characterized cytokine profiles in peripheral blood mononuclear cells (PBMC) and neutrophils following SARS-CoV-2 vaccination with Pfizer-BioNTech (mRNA-based) and AstraZeneca (adenoviral vector-based) vaccines in Kuwait. The study included 200 adult participants: 100 unvaccinated healthy controls; 18 recipients of two Pfizer-BioNTech doses; 32 recipients of two AstraZeneca doses; and 50 recipients of a third Pfizer-BioNTech dose. Blood samples were collected at 0-2 months and 3-6 months after vaccination, and cytokines were measured in mitogen-stimulated PBMC and neutrophil culture supernatants. Both vaccine platforms induced measurable cytokine responses, but the cytokine patterns differed according to vaccine type, cell population, and time after vaccination. Pfizer-BioNTech vaccination was associated with an early Th2-skewed profile in PBMC, while AstraZeneca vaccination showed broader activation of Th1/Th2/Th17-associated cytokines. IL-6 and IL-10 decreased over time in several comparisons; however, these findings should be interpreted with caution because cytokine concentrations are dynamic and may vary with sampling time, cell type, and stimulation conditions. Overall, vaccine-induced cytokine profiles waned by 3-6 months after primary vaccination, whereas the third Pfizer-BioNTech dose enhanced several PBMC cytokine responses. These findings support the immunomodulatory effects of SARS-CoV-2 vaccines and highlight the value of booster vaccination for sustaining cellular immune responsiveness.