New DIVA vaccine candidates against peste des petits ruminants virus
Two new vaccine candidates that could differentiate between vaccinated and infected animals and contribute to the goal of global eradication of peste des petits ruminants virus (PPRV) have been developed by researchers at The Pirbright Institute.
In a study published in Viruses, researchers explored ways to create live attenuated DIVA (Differentiating Infected from Vaccinated Animals) vaccines using reverse genetics which provides a way to manipulate the RNA virus genome through DNA copies (cDNA). Using these techniques, researchers have taken current vaccine strains of PPRV and replaced the variable part of the N gene (a gene that codes for nucleoproteins which play a role in the host’s immune response), with that from a related virus, dolphin morbillivirus. These modified strains of PPRV were then assessed for their growth characteristics in the laboratory and were found to behave similarly to the parent strains. They were also found to be safe and offer protection against disease for vaccinated goats similar to parent vaccine strains. To demonstrate that these vaccines were DIVA vaccines, ELISAs were designed to successfully differentiate antibodies in the blood of infected and vaccinated animals.
Prof Satya Parida who led the research and was head of the Vaccine Differentiation Group while at Pirbright, now working at the Food and Agriculture Organisation of United Nations (FAO) as laboratory and vaccine specialist said, “This is a key breakthrough in the global eradication of PPRV as a DIVA vaccine was the next piece of the puzzle. It allows for surveillance of animals to determine disease spread and monitor outbreaks, while also protecting animals and preventing virus shedding. We also showed that these novel vaccines can protect against any of the four lineages of PPRV. The next step is to test the efficacy of these DIVA vaccines on a larger number of animals to further establish the safety and potency before they are used in the field.”
Article: Selvaraj, M., Mahapatra, M., Parida, S. (2021). Exchange of C-Terminal Variable Sequences within Morbillivirus Nucleocapsid Protein Are Tolerated: Development and Evaluation of Two Marker (DIVA) Vaccines (Sungri/96 DIVA, Nigeria/75/1 DIVA) against PPR. Viruses, 13(11), 2320, doi: 10.3390/v13112320
[SOURCE: The Pirbright Institute]