A cDNA clone representing the genome of structural proteins of Japanese encephalitis virus (JEV) was inserted into the thymidine kinase gene of vaccinia virus strains LC16mO and WR. Inoculation of rabbits with the infectious recombinant vaccinia virus resulted in rapid production of antiserum specific for the PreM and E glycoproteins of JEV. Mice vaccinated with the recombinant produced JEV-neutralizing antibodies and were resistant to challenge with JEV (Yasuda et al., 1990).