Intranasal Immunization with a Recombinant Avian Paramyxovirus Serotypes 2 Vector-Based Vaccine Induces Protection against H9N2 Avian Influenza in Chicken

Even though the inactivated viral vaccine against H9N2 avian influenza viruses proved successful, it could not match the clinical demands of the live viral vectored vaccine. NDV can be utilized as a live vectored vaccine, but preexisting maternal antibodies reduce its effectiveness. Therefore, recombinant Avian Paramyxovirus-2 (APMV-2) expressed H9N2 HA was investigated as a live viral vector vaccine against the H9N2 avian influenza virus by intranasal vaccination. The rAPMV-2/HAs viruses were generated by the reverse genetics method. The biological characteristics and pathogenicity of the rAPMV-2/HAs were similar compared with the parental APMV-2-T4 virus. Experimental investigations on animals revealed that vaccination with rAPMV-2-NP-UTR-HA elicited robust H9N2-specific antibody responses and conferred complete immune protection to prevent viral shedding in the oropharyngeal and cloacal swabs from chickens challenged with the H9N2 virus. Therefore, rAPMV-2-NP-UTR-HA might be a good live viral vector vaccine candidate suitable for mass vaccination of commercial chickens in field conditions.

(MMR)

Development and Scalable Production of Newcastle Disease Virus-Vectored Vaccines for Human and Veterinary Use

A possible platform that has been authorized for use against the SARS-CoV-2 and Ebola viruses is the viral vector. NDV has been intensively researched for its oncolytic potentials, but because of its safety, immunogenicity, thermostability, and capacity to produce a variety of antigens directed against both veterinary and human diseases, it can also be an excellent choice for a viral vaccine vector. NDV-vectored vaccine candidates have been developed for a range of pathogens, including HIV, EBOV, and predominantly respiratory viruses such as influenza, SARS-CoV, SARS-CoV-2, and the Avian Influenza virus. Moreover, genetically modified chimeric NDVs that alter surface antigens can be used as potential vectors for animal disease vaccines. Nevertheless, there are several shortcomings in the large-scale production of NDV vector viruses. The NDV vector vaccine is commonly manufactured in embryonated chicken eggs and cell lines. More than ever, it is crucial to close the gaps in the process development of NDV-vectored vaccines for humans by evaluating and perfecting scalable NDV manufacturing techniques employing cell culture in bioreactors.

(MMR)