Aim: To study and analyze data on clinical and laboratory parameters of investigated children in 6 months after treatment and 6 months after Covid-19 vaccination. Materials and Methods: A prospective clinical and laboratory examination of a children group (group 1) with identified Covid-19 (n=68) was carried out in comparison with a group (n=31) of Covid-19 vaccinated children (group 2) after 6 months of observation. Results: The data of Anti-SARS-CoV-2-S1-RBD IgG, non-significant intergroup differences in levels were found (344.71 ± 87.62 versus 315.67 ± 74.91 BAU/ml, p=0.11). Significant differences were found in the children group who was 6 months after Covid-19 treatment and the control group, as well as in the group before and 6 months after Covid-19 vaccination, in the following parameters: IL-2 (p6<0.01; p7<0.01, with a prevalence of 6 and 4 times, respectively); IL-4 (p6<0.01; p7<0.01with a prevalence of 6 and 4.6 times, respectively), IL-10 (p6<0.01; p7<0.01 with a prevalence of 6 and 4.8 times, respectively), Procalcitonin (p6<0.01; p7<0.01, 18 times and 1.4 times respectively). Conclusions: In our study, according to the data of multivariate linear regression analysis, the level of Anti-SARS-CoV-2-S1-RBD IgG is the dependent variable, and D-dimer, Na level, Total Cholesterol, LF, IL-6, IgG are the influencing factors which determine the COVID-19 anti-infective protection.