A One Health approach to bovine coronavirus vaccine development, using LSDV as a live virus vector

Bovine coronavirus (BCoV) causes significant pneumo-enteric infections in cattle and other ruminants. A BCoV-like coronavirus was previously found in a symptomatic human child and shares 97.1% sequence identity with one of the more prevalent human coronaviruses, HCoV-OC43. Zoonosis of a virulent BCoV from livestock is a feasible threat. Lumpy skin disease virus (LSDV) is a poxvirus that can be used as a live attenuated dual vaccine vector in cattle and potentially as a replication-deficient vaccine vector, in humans. This paper explores the development of a vaccine, considering the increasingly significant One Health approach, which recognizes the importance of curbing disease at the animal-human interface to prevent future epizootics and pandemics. A recombinant LSDV (LSDV-BCoV-K1L) was developed to express the spike and nucleocapsid proteins of BCoV. The spike and nucleocapsid antigens used in this vaccine were derived from consensus sequences of 38 spike and 24 nucleocapsid amino acid sequences, encompassing multiple BCoV genotypes. The insertion of the foreign gene cassette between LSDV open reading frames 49 and 50 was verified using polymerase chain reaction and DNA sequencing. Furthermore, western blot analysis confirmed the expression of BCoV spike and nucleocapsid proteins in cells infected with LSDV-BCoV-K1L. The immunogenicity of LSDV-BCoV-K1L was evaluated in mice and compared to the parent virus, nLSDVSODis-UCT. Mice immunized with LSDV-BCoV-K1L produced nucleocapsid-specific T-cells and high levels of spike-specific antibodies. This combined vaccine targeting both lumpy skin disease virus and BCoV requires further evaluation.