Genetic analysis of the blue tongue virus (BTV) currently found in the field indicates that it is the same virus found last year (BTV-3/NET2023). This is the result of research by Wageningen Bioveterinary Research (WBVR, part of Wageningen University & Research) commissioned by the Dutch Ministry of Agriculture, Fishery, Food security and Nature (LVVN).
To determine the genetic composition, a so-called sequence analysis is done. The sequence is mapped at the level of RNA and virus proteins. All the sequences together form the complete genetic material of the virus. "Our research shows that the bluetongue virus found in the field in 2024 is practically identical to the virus we found in September/October 2023," said WBVR researcher Marc Engelsma. The similarities are more than 99.9 percent at both nucleotide level (genetic material) and protein level (virus proteins).
Immunogenic protein
For the immunogenic virus protein VP2, the similarity is even 100 per cent. "This VP2 protein is the most important immunogenic protein," Engelsma explains. The body recognises such an immunogenic protein of a virus as foreign to the body, the immune system makes antibodies against that protein and thus tries to clear the virus. Vaccines are designed to stimulate or accelerate this process. The BTV-3 vaccines authorised for use in the Netherlands are based on killed-off BTV-3 that also contains this protein. "Based on this genetic analysis, we conclude that there are no changes in the virus itself that affect the efficacy of the three available vaccines authorised for use."
