The present invention is directed to a reassorted ISA virus comprising Genome segments 1-8 wherein at least one genome segment is from Genotype I and at least one genome segment is from genotype II, wherein genome segment 6 is of Genotype II. The reassorted ISA virus was found to grow well in suspension culture. The present invention is also directed to method to make the reassorted virus as well as vaccination methods using the reassorted ISA virus and to vaccine compositions comprising the reassorted ISA virus.