Recombianant Hepatitis a virus

The present invention is directed to genetically engineered expression systems which encode a recombinant Hepatitis A virus (HAV) proteins capable of forming capsid particles. By way of example baculovirus vectors were utilized in order to express recombinant HAV proteins. The recombinant baculoviruses of the invention are formed by replacing regions of the polyhedrin structural gene coding sequences with HAV DNA by recombinant DNA techniques. Additionally, the polyhedrin transcriptional initiation site is altered in these recombinant baculoviruses such that only HAV proteins and not polyhedrin protein sequences are expressed from the polyhedrin promoter. The recombinant HAV capsid particles produced in accordance with the present invention can be particularly useful as vaccines.