Detection of long term cellular immune response to Japanese encephalitis vaccination using IFN-γ ELIspot assay.

Vaccine is the most effective preventive measure against Japanese Encephalitis infection. Role of IFN-γ expressing T cells for JE virus clearance has been described as a part of cellular immunity. Vaccine induced immunity also involve the cellular immune response, therefore the study was aimed to observe induction and persistence of IFN-γ expressing T cells by IFN-γ ELISpot assay. The cell count increased significantly after 28 (P < 0.0001) days post vaccination, and remained higher at all time points (day 28, day 180, day 360) when compared with prevaccination. This study will be helpful for designing future vaccination strategy and improving vaccine efficacy.