[The cell-mediated response after measles vaccination].

Natural measles virus infection is recognized for causing prolonged abnormalities in immune responses, that contribute to the severe and complicated evolution of the disease. Immunization with live measles virus vaccine could be considered a mild form of the measles infection. Results of investigation of in vitro immune response after measles immunization with live attenuate vaccine have been conflicting. In this work we studied cellular immune parameters in children aged between 3 and 12 years. T cells, CD4+ and CD8+ subsets were analyzed by cytometry. CD3+ cells were significantly reduced compared to controls (p < 0.01) whereas CD4+/CD8+ ratio was normal. The in vitro proliferative response to polyclonal mitogen was significantly reduced (p < 0.01). This study confirms the presence of a mainly functional immunosuppression of cellular response in a cohort of children belonging to a developed area. These findings improve the understanding of the mechanism of immune response to virus measles and provide suggestions for the development of a better approach to immunization, taking account for the strain, vaccine titre, age and environmental conditions of the target population.