Cytokine production and TLR 7/8 gene expression following BBIBP-CorV COVID-19 vaccination

Abstract

Introduction and objective

The impact of inactivated vaccines for COVID-19, BBIBP-CorV COVID-19, on the human immune system was not studied. This study investigates the immune response induced by the BBIBP-CorV COVID-19 vaccine.

Method

A total of 90 blood samples (5 ml each) were collected from participants (mean age: 20 years) in Basrah, Iraq. The study included 60 vaccinated individuals (38 males, 22 females), 60 days post-BBIBP-CorV vaccination and 30 unvaccinated controls (15 males, 15 females). Blood was divided: 2 ml in EDTA tubes for TLR7/TLR8 mRNA expression (RT-qPCR) and 3 ml in clotting activator tubes for serum isolation to measure IL-7, IL-10, IL-12, IL-18, and IL-21 levels (sandwich ELISA). Data were compared with controls and analysed for statistical differences. Volunteers with flu, COVID-19 symptoms, fever, chronic diseases, or immunocompromised conditions were excluded.

Results

The BBIBP-CorV vaccine did not disrupt cytokine production, with no significant differences in IL-7, IL-10, IL-12, IL-18, and IL-21 levels between vaccinated and unvaccinated groups after 60 days (p > 0.05). However, TLR7 and TLR8 mRNA expression was significantly upregulated (p < 0.05) in vaccinated individuals compared to controls, indicating enhanced innate immune activation without affecting cytokine balance. These findings highlight the vaccine's ability to stimulate immunity while maintaining normal cytokine levels.

Conclusions

These results are particularly significant as they demonstrate that the BBIBP-CorV COVID-19 vaccine successfully induces immunological responses via TLR7 and TLR8 activation without abnormal effects on cytokine production. As a pilot study, these findings lay a strong foundation for future research.