Introduction
Viral Nervous Necrosis (VNN), also known as Viral E ncephalopathy and Retinopathy (VER), is caused by a virus belonging to the genus Betanodavirus of the Nodaviridae family. The disease has been described in more than 50 fish species and is still considered a serious threat to aquaculture . Farmed European sea bass is severely affected , the virus is causing animal suffering and significant losses to the industry. Because of the need for preventive measures, Pharmaq developed a vaccine against VNN and the demand for vaccines is growing.
Methods and Results
Development of the monovalent injection vaccine targeting Viral N ervous N ecrosis V irus (VNNV) was initiated in 2012 and extensive research and documentation continued up to 2017 when the first Marketing Authorization was granted. Developing a robust and reproducible challenge model is key to be able to test and document vaccine efficacy. Protection was assessed clinically* through dose-response studies, evaluation of onset- and duration of immunity, and cross protection testing using challenge isolates of various origin. The safety of the vaccine, including local reactions such as abdominal adhesions and pigmentation, was investigated after vaccination . Extensive clinical testing under controlled laboratory conditions showed that the vaccine is safe to use and provides high levels of protection, which has been further supported by experience from the field. Data have also been gathered after large scale commercial use of the vaccine, and feedback from farmers has been vital to monitor efficacy and safety.
This presentation will review the highlights of the development process, with a special focus on clinical studies. Current field situation will also be addressed.
*The pre-clinical studies were conducted in line with the “License to Carry out Research on Animals” granted to AquaBioTech Group by the Ministry for Agriculture, Fisheries, Food and animal rights, Animal welfare Department in Malta and in accordance with procedures approved by the Zoetis Animal Ethics Committee.