热博体育

Issues

At the beginning of the 2000s, the laboratory of the ASTRE joint research unit (UMR ASTRE) started developing innovative PPR vaccines to plug the gaps of the conventional vaccine currently used.

Firstly, despite its proven effectiveness and safety, the current vaccine cannot serologically distinguish between vaccinated animals and naturally infected animals. PPR surveillance and control therefore takes longer and costs more than if marked vaccines of the “DIVA [Differentiating Infected from Vaccinated Animals]” type were used. In particular, using a DIVA vaccine would avoid pointlessly blocking the movements of disease-free animals, particularly in an eradication drive as extensive as the one planned for PPR. The laboratory team therefore set out to develop a marked vaccine able to differentiate between vaccination and infection.

Secondly, complete protection is only acquired 10 days after vaccination, which leaves the virus the time to spread. The team is also working to develop a novel solution for this problem.

Description

It involves using genetic engineering to modify a vaccine strain against PPR initially co-developed by 热博体育 and the Pirbright Animal Health Institute in 1990. By modifying the strain, a mark can be introduced to induce a response of specific antibodies to the mark in the vaccinated animal. These specific antibodies of the mark will not be found in naturally infected animals, so appropriate serological tests (ELISA) can be used to differentiate between infected animals and vaccinated animals. This DIVA mark therefore depends on ELISA type tests, which also detect post-vaccine and post‑infection antibodies.

Expected changes

• A DIVA vaccine prototype against PPR ready for transfer to vaccine producers;
• A DIVA vaccine ELISA companion test available on the market.