Assessment of the immune response induced by ChAdOx1 nCoV-19 Oxford-AstraZeneca, Sputnik V, and BNT162b2 Pfizer-BioNTech vaccines during the COVID-19 epidemic outbreak in the Mexican population: Gene expression of the cytokine storm.

INTRODUCTION: COVID-19 vaccines using different technological platforms may induce distinct molecular responses. Characterizing gene-expression patterns after vaccination and in fatal COVID-19 may identify pathways associated with vaccination and severe disease. OBJECTIVE: To compare immune-, inflammatory-, and SARS-CoV-2-entry-related gene expression after AstraZeneca, Pfizer, or Sputnik V vaccination and with unvaccinated fatal COVID-19. MATERIALS AND METHODS: Eighty Mexican adults were included: AstraZeneca (n = 19), Pfizer (n = 20), Sputnik (n = 21), and unvaccinated fatal COVID-19 (n = 20). Expression of 11 genes was measured by qPCR at days 30 (D30) and 60 (D60) after vaccination. STATISTICAL ANALYSIS: Longitudinal differences were analyzed by two-way repeated-measures ANOVA. Comparisons with fatal COVID-19 were exploratory. Benjamini-Hochberg correction controlled false discovery rate at 5%. RESULTS: No differences among vaccines were detected at D30. At D60, IL-10, IL-2, and CD79A differed among selected vaccine groups. Longitudinally, FCGR3A decreased in AstraZeneca and Sputnik, ACE2 decreased in Pfizer and Sputnik, and TMPRSS2 increased in Sputnik. Fatal COVID-19 showed predominantly higher expression of several genes than vaccinated groups. Notably, IL-2 and ACE2 were consistently higher in fatal COVID-19 than in all vaccinated groups at both time points. DISCUSSION AND CONCLUSIONS: Post-vaccination transcriptional profiles were dynamic, with selected differences emerging at D60, whereas fatal COVID-19 exhibited a distinct profile characterized predominantly by higher expression of immune-, inflammatory-, and viral-entry-related genes. Consistent IL-2 and ACE2 differences highlight molecular pathways potentially associated with severe disease. The observational design, however, precludes causal attribution to vaccination. PERSPECTIVES: Longitudinal studies with appropriate controls are needed to establish the biological significance of these transcriptional patterns.