Evaluation of the Efficacy of a Recombinant Adenovirus Expressing the Spike Protein of Porcine Epidemic Diarrhea Virus in Pigs

Liu, Xinsheng; Zhao, Donghong; Zhou, Peng; Zhang, Yongguang; Wang, Yonglu

At present, all commercially available vaccines, especially in Asia, are traditional live attenuated or inactivated/ killed vaccines, and their efficacy needs to be further developed and improved through further study [11, 17, 18] . erefore, many studies have been carried out for the development of next-generation PEDV vaccines based on the S protein, such as a recombinant Lactobacillus vaccine [19] , a recombinant DNA plasmid vaccine [20] , an attenuated Salmonella typhimurium vaccine [21] , a recombinant Parapoxvirus vaccine [22] , a recombinant orf virus (ORFV) vaccine [23] , and a recombinant vesicular stomatitis virus (VSV) vaccine [24] . Moreover, the first commercial PEDV vaccine used in the US, called the iPED vaccine, was based on a truncated version of the PEDV spike gene and a pVEK replicon vector derived from the Venezuelan equine encephalitis virus [14] . e vaccine induced immunity in young pigs after two doses given intramuscularly (IM) in a three-week interval, significantly reduced the severity of clinical signs (diarrhea), and reduced viral shedding for the first 72 hours [14] . Going forward, new genetically engineered vaccines will be an important direction for the development of PEDV in the future.