Worldwide, there are millions of afflicted individuals. by SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2, which is the cause of the COVID-19 global pandemic. reactions to vaccinations and the SARS-CoV-2 virus that trigger immunity. Numerous COVID-19 vaccines have been developed so quickly. Both cellular immunity, which consists of helper CD4+T cells and cytotoxic CD8+ T cells, and humoral immunity, which is mediated by antibodies and memory B cells, are responsible for producing protective immunity, which can be triggered by vaccination or infection. With minimal attention paid to cellular immunity, the majority of research on COVID-19 vaccines has been on neutralising antibody (NAb) responses. Mechanistic immunological correlates of vaccination protection as well as the duration, effectiveness, and type of immunity generated throughout SARS-CoV-2 infection are yet little known. Our research examined the response of SARS-CoV-2 T cells in 40 patients who recovered and in 40 more people who received the vaccine. Six to twelve months post-symptom onset (PSO), every patient exhibited measurable results of SARS-CoV-2-specific CD3+, CD4+, or CD8+ T cells; the immunisation group also showed similar outcomes. When we examined the T cell response in COVID-19-vaccinated individuals to non-vaccinated convalescent patients, we discovered that there were no statistically significant changes between the two groups in terms of overall T cell populations, namely CD3+ T cells, CD8+ Tc cells, and CD4+ Th cells. Our findings offer important proof that, in most patients, the response of T cells continues at least a year after an infection or immunisation.