iarjimphIARJIMPHIARJIMPH2709-331Xhttps://doi.org/10.47310/iarjimph.2022.v03i01.021Role of Hemocytometry in Early Predicting COVID 19 Infections, a Comparison Study Between Non-Vaccinated and Vaccinated CasesSadeelOsama TahaAlshabkhoonHibaRafeaTaherEsraaAdelMahmoodAlthough the novel pandemic COVID-19 a primary respiratory tract infection, it is a multi-systemic illness, and has an important impact on the haemopoietic cells. The purposes of this study is to concentrate on the possibility of utilizing the hemocytometry results in predicting the infected cases during epidemic periods. Methods: A total 220 cases included in this study, (118 males, 102 females), divided into 3 groups, 1st group represent those of second wave of pandemic COVID-19 in Iraq, 2nd group during period of third wave, and 3d group includes post vaccine infection. Using the 5 diff Sysmex autoanalyzer for complete blood count as a rapid, informative, cheap test. Results: About 1/3d of group 1 and 2 (37%, 33%) respectively are presented with leukocytosis while no one of vaccinated group, in opposite to leucopenia, more common in 3d group (25%), while in group 1and 2only few (8%, 11%) cases respectively. Thrombocytopenia is infrequent in all three groups. The differential white blood cell count is symmetrical in 1st and 2nd group, all patients presented with eosinopenia followed by high N/L ratio (84%, 92%) -whether due to neutrophilia and/or lymphopenia, or both within normal range-, this is not the finding in post-vaccinated group, eosinopenia presented in 25%, of cases and neutropenia is the most common finding 31% in 3d group, while lymphopenia is rare in third group.