Prevention of zoonotic tissue cyst formation in sheep using live attenuated and parapoxvirus vector based vaccines against Toxoplasma gondii

Description

Toxoplasmosis is among the most important foodborne infections worldwide. In the EU, most human infections are due to consumption of meat containing Toxoplasma gondii tissue cysts. Prevalence of Toxoplasma is higher in outdoor reared animals, such as sheep, than in animals reared indoors, and consumer interest in animal welfare and free-range meat production may contribute to a further increase in the prevalence of Toxoplasma unless control measures are implemented. Vaccination of consumption animals to prevent Toxoplasma infection and tissue cyst formation could be highly effective in reducing the disease burden in humans. The only commercially available vaccine against toxoplasmosis in sheep, Toxovax, prevents congenital disease in lambs but the effect of vaccination on tissue cyst development has not been studied. Toxovax uses a live attenuated strain of T. gondii and there may be a risk of the vaccine strain reverting back to wild-type and causing disease in animals or humans. We propose to develop a safer vaccine strategy based on a recombinant parapox-virus expressing Toxoplasma antigens (TOXPOX). We will compare efficacy of TOXPOX and Toxovax in the induction of a protective immune response and the prevention of tissue cyst development using advanced immunological and molecular methods which reduce the need for use of experimental animals. A safe vaccine effective in preventing the formation of zoonotic tissue cysts in sheep is our ultimate goal. The specialized laboratory and animal facilities at Moredun and the host expertise in parasitology, virology and immunology provide the best possible infrastructure and mentoring environment to bring this project to a success. Working on this multidisciplinary project in combination with complementary skills training offered at Moredun and its affiliated organizations in the Easter Bush Research Consortium will be of indispensable value to the applicants career progression.

KEY DATES
  • Status
  • Completed
  • Project Launch
  • 01 April 2012
  • Project completed
  • 31 August 2013
Toxoplasmosis food disease
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