ABSTRACT
Objective To evaluate and compare the cellular immune response induced by live at-tenuated and inactivated hepatitis A vaccines. Methods A total of 18 healthy volunteers were enrolled in this study. They were divided randomly into 2 groups and injected by inactivated hepatitis A vaccine and at-tenuated hepatitis A vaccine, respectively. All volunteers' heparinized venous blood was separately collected for testing anti-HAV antibody and the responses of PBMC. The level of IFN-γsecreted by effect T cell was tested by ELISPOT. The percentage of lymphocytes secreting IFN-γ from CD+ and CD8+ T cell was tested by intracellular cytokine staining (ICS) technique. The concentrations of IFN-γ, IL-2, IL-10 and IL-4 in the culture supernatants(grown in the presence or absence of HAV) of the in vitro HAV-primed PBMC were determined by Luminex. Results These two types of vaccines can elicit specific anti-HAY antibodies and no statistical significance between them were observed. At the early stage after inoculation, T cell-mediated immune responses with the secretion of IFN-γ were detected in vaccines inoculated with either type of vac-cines. There was a tendency that the cellular immune responses level induced by inactivated hepatitis A vac-cine was higher than that by live attenuated hepatitis A vaccine during 1 to 3 weeks post-injection. The booster inoculation could significantly increase the level of cellular immune responses induced by the inacti-vated vaccine. Conclusion Both live attenuated and inactivated HAV vaccines can elicit an earlier specific humoral and cellular immune responses, and booster inoculation of inactivated HAV vaccine can rapidly and intensively evoke memory immune responses.