Abstract: Disclosed is a recombinant vertebrate F such as vaccinia virus which comprises in its genome (i) spheroidin promoter of entomopoxvirus such as Choristoneura biennis and (ii) at least one structural gene coding for at least one protein foreign to entomopoxvirus and to the vertebrate poxvirus and is capable of expressing the foreign protein gene in a vertebrate tissue culture cell or in a vertebrate animal susceptible to the vaccinia virus. The recombinant virus is capable of expressing the foreign gene at a significantly higher rate due to the presence of the entomopoxvirus spheroidin promoter than the same virus without the entomopoxvirus promoter. The protein may be antigenic or otherwise pharmaceutically useful. Also disclosed vaccine and a process for producing the protein using the recombinant virus.