Edible Vaccines: eating our way to the eradication of disease

There is a clear need for new vaccines, and vaccination strategies Eradication of small-pox Vaccine preventable diseases millions of deaths per year No vaccines HIV; ~2 million deaths per year malaria; 1.5 - 2.7 million deaths per year There is a clear need for new vaccines, and vaccination strategies

Why is measles still killing children? Failure to vaccinate: fear safety and side effects misconceptions prevalence and seriousness access/availability Vaccine failure: inactivation by heat interference by maternal antibodies

A subunit based edible vaccine? economical heat stable oral administration no more needles mucosal immune response sub-unit vaccine unable to replicate overcome maternal antibodies

Developing an edible vaccine for measles select an antigen Hemagglutinin (H) protein surface exposed protein targeted during the immune response sufficient to induce protective immunity H F P RNA + N L M

Tobacco expressing the MV-H protein MV-H control PNGase F - + - + 100kDa 75kDa 50kDa Transgenic tobacco Western blot

Feeding tobacco induces MV neutralising antibodies in mice

Feeding tobacco may also induce a mucosal immune response titre MV-H Control Naive Treatment groups

From model system to practical vaccine Edible species lettuce tobacco control rice control 75kDa MV-H 50kDa

From model system to practical vaccine Edible species – intraperitoneal experiment MV-specific serum IgG titers MV-H tobacco MV-H lettuce control lettuce

From model system to practical vaccine Edible species – intraperitoneal experiment MV-neutralisation titers MV-H lettuce control lettuce

From model system to practical vaccine an edible species delivery and dose issues quantity and number higher antigen expression in plants targeting the antigen for better uptake safety issues quality control and licensing GMO issues

tobacco, lettuce and rice can express the MV-H protein Summary: tobacco, lettuce and rice can express the MV-H protein plant-derived MV-H protein is able to induce MV neutralising antibodies in mice edible vaccines have the potential to address the limitations of the current measles vaccine

Acknowledgements Viral Vaccine Unit, CSIRO, Adelaide (Monash University) Steve Wesselingh Jenny Martin Diane Webster Michelle Cooney Zhongjun Huang CSIRO, Adelaide Ian Dry Terri King Steve Choimes Melbourne University Richard Strugnell