 This difference results in different neuraminidase conformations around the receptor binding site and variations in neuraminidase activity between the two viral variants.Another research study shows that SeV variants, adapted to grow in cell culture 4647 (African green monkey kidney cells) and in HEK 293 (human embryonic kidney cells) instead of embryonated chicken eggs, also acquire mutations in HN gene and both SeV variants lost their oncolytic activity.All Sendai virus strains belong to the same serotype.