Mucosal DNA vaccination in infected sheep
Mucosal immunisation is the administration of a vaccine that enters the body through the mucosal membrane, which lines the body's passages and cavities. These include the gastrointestinal, respiratory and urogenital tracts as well as the inner and middle ear and the eyes. Therefore, any vaccine taken orally will take the gastrointestinal mucosal route of immunisation, for example. Researchers from the MVAC project evaluated mucosal DNA vaccination in sheep infected with the maedi visna virus (MVV), which causes encephalitis and chronic pneumonitis. The team found that antibody responses were elevated after plasmid immunisation. There was no evidence that the commercially available vaccine modified vaccinia Ankara (MVA) boosted the antibody response. Most animals developed detectable antibodies in their blood serum after being challenged with MVV. However, there was not a significant difference in antibody concentrations between immunised and control groups. Immunisation with gag resulted in an increase in IFNg (interferon gamma) production by T cells, compared to controls, seven weeks after DNA immunisation. T cell cytotoxic responses were extremely limited before and after mucosal immunisation.
