Preclinical evaluation of a recombinant MVA expressing the hemagglutinin-neuraminidase envelope protein of parainfluenza virus 5 (Mammalian orthorubulavirus 5)

PIV 5 (Mammalian orthorubulavirus 5 - ICTV, 2021, previously known as Parainfluenza virus 5) is one of the main causes of ITB (infectious tracheobronchitis) affecting dogs, with a global distribution and potential to generate outbreaks from time to time. The currently available vaccines against the disease do not prevent the symptoms, require a high number of doses, and use adjuvants that, in addition to the cost of production, are responsible for adverse reactions, sometimes severe. Such drawbacks have raised the interest for new vaccine's development against ITB. In this context, we designed a recombinant immunogen based on the modified Vaccinia virus Ankara (MVA) expressing the hemagglutinin-neuraminidase (HN) envelope protein of PIV 5, and evaluated the immunogenic potential of this vaccine in C57BL/6 female mice. For the immunogenicity analyzes, epitopes of CD8⁺ T cell for the MHC-I murine alleles were predicted in silico, evaluated in vitro through flow cytometry and ELISA assays, and were used to evaluate the CD8⁺ T cell responses. The efficient expression of the envelope protein by the recombinant vector, allied to the immunogenic responses in vivo, highlights the potential of our recombinant MVA as a vaccine against PIV 5.