Sequential vaccination against influenza and COVID-19, and innate immunity indexes: efficiency aspects

Evaluation of cytokine dynamics during vaccination is an important aspect in assessing the vaccine preventive efficiency and personalized approach to combined vaccination. Our aim was to study the impact of influenza and COVID-19 vaccination on innate immunity in young patients by assessing the time-related changes of cytokine profile. The study group included 76 young adults of 19 years old. The cytokine contents were studied in venous blood sera by enzyme immunoassay. The first series of blood samples was taken before influenza vaccination; the second sampling was performed 1 month after influenza vaccination and before COVID-19 vaccination; the third series was carried out 1 month after COVID-19 vaccination and 2 months after influenza vaccination. The results were processed by Statistica-10 and SPSS v. 20 software. The vaccinated persons were monitored for 6 months after vaccination. IL-8, IL-17 levels before vaccination were above normal in 100% of subjects; IL-6, in 76% of cases. IL- 1â, IL-4 and IL-10 levels were under normal levels in more than 50% of cases. After influenza vaccination, a significant decrease in cytokine levels was observed: IL-1â comtet was below normal values in 89%; IL-4, in 100% of cases, as well as IL-6 (in 79%), IL-8 (in 74%), IL-10 (in 89%), IFNã (in 63%), TNFá (in 76%), and only IL-17 was within normal ranges in 72% of cases. After vaccination against COVID-19 and influenza, a more rapid decrease in cytokine levels was observed: IL-1â was below baseline values in 95%, IL-6, IL-8, IFNã and TNFá were reduced in 100%; IL-10, in 90% of cases, along with normalization of anti-inflammatory IL-4 cytokine. Despite a significant decrease of the indexes, we revealed multiple strong multidirectional correlations between the cytokine contents, being especially significant between IL-1â, IL-6, and IL-8. During 6-mo observation after vaccination, two cases of COVID-19 (2.6%) were documented and confirmed by PCR test. No influenza cases have been detected over this period. At the begining of the study, a favorable cytokine background for effective vaccination was observed. After vaccination against COVID-19 and influenza, a decrease of the pro- and anti-inflammatory cytokine levels was recorded, and strong correlations were found, thus suggesting an increase in the immune response following vaccination. The changes of IL-1â, IL-6, IL-8 were most remarkable at all stages of vaccination.