Effects. During an infection, your body produces a greater number of white blood cells. This is called leukocytosis. Depending on the type of infection, one of the specific white blood cell types may be elevated more than others.For example, during bacterial infections, neutrophils are elevated.ignificance. Another effect of certain infections is to lower the white blood cell count. A decrease in the level of white blood cells is called leucopenia. According to MedlinePlus, infections with certain viruses, such as parvovirus, can suppress the production of these cells in the bone marrow.