COVID-19 is a life-threatening infectious disease affecting mainly the upper-airways. This disease caused by the SARS-CoV-2 RNA virus has been causing millions of deaths worldwide since December 2019, and it was announced as a pandemic already in March 2020 by World Health Organization. In this study, the SARS-CoV-2 specific T cell activation was studied by using a novel whole blood method. The heparinized whole blood samples from 190 individuals, who had experienced mild /moderate symptoms or been exposed to COVID-19 in the work environment, were stimulated with S1 peptides and peptide-mix containing M, S, and N peptides of the SARS-CoV-2 genome. The samples were stained with OX40, CD25, CD69, and CD137 fluorescent marked antibodies to detect potential antibody markers specific to SARS-CoV-2 T cells. The stimulated samples were further analyzed using flow cytometric assay. Results showed that S1 peptide stimulated SARS-CoV-2 specific CD4+ T cells were significantly expressed among the infected individual whereas CD8+ T cell activation was not significantly detected. Also, OX40/CD25 antibody marker combination was found to be more potent than the combination of CD69/CD137 in the detection of activated CD4+ T cells. Previously reported pre-existing T cells for SARS-CoV-2 were studied in the samples activated by the peptide-mix. As expected, pre-existing T cells were detected among the individuals, who had not had SARS-CoV-2 infection. Overall, the study showed the potentiality of the new whole blood method in the detection of antibody-specific T cells. In order to introduce this method into clinical settings, it needs to be studied further.