1. Edible Vaccines: eating our way to the eradication of disease

2. 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; million deaths per year
There is a clear need for new vaccines, and vaccination strategies

3. 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

4. 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

5. 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

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

7. Feeding tobacco induces MV neutralising antibodies in mice

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

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

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

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

12. 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

14. 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

15. 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