Multiple basic amino acids have been demonstrated in the virus (either directly or by deduction) at
the C-terminus of the F2 protein and phenylalanine at residue 117, which is the N-terminus of the
F1 protein. The term ‘multiple basic amino acids’ refers to at least three arginine or lysine
residues between residues 113 and 116. Failure to demonstrate the characteristic pattern of
amino acid residues as described above would require characterisation of the isolated virus by an
ICPI test.’