Evaluation and Optimization of Chick Embryo Fibroblasts for Production of a Fowl Pox Vaccine Based on Cell Culture

Abstract Background and Aims: For more than half a century, the production of fowl pox vaccine at Razi Vaccine and Serum Research Institute, has been carried out by injection method in the chick chorioallantoic membrane (CAM) and the vaccine has a favorable and effective in poultry flocks and has provided a complete satisfaction to the poultry flocks owner. Fowl pox vaccine is also manufactured using chicken embryo cell (CEF) culture in other countries. The aim of this project is to develop fowl pox vaccine based on CEF which is of vital importance and a requirement for Razi institute. Materials and Methods: In this study, chicken fibroblastic cells were used as primary cell culture in Hanks or DMEM media supplemented with fetal bovine serum 10% (FBS). First the cells were cultured and the cell count was determined. Subsequently, the virus was added to the cells. The virus that used to prepare the vaccine was initially grew up in the fibroblast cells and had a titer of 106.3 TCID50/ml. To determine the viral load, two methods plaque-forming unit (PFU) and TCID50 were used, safety and efficacy tests were performed on 10 chickens, and the potency test on 20 chickens, and vaccinated chickens were challenged with wild fowl pox virus strain. Results: The results of the tests showed that the vaccinated chickens had an adequate and sufficient resistance to the acute form of fowl pox virus. Conclusion: In total, according to the OIE standard, the above experiments showed that cell culture-based fowl pox vaccine can generate good immunity response and have high efficacy.