Table 4. The parameters of codon usage bias pre- and post-codon adaptation of the vaccine construct .

Parameter	Before	After
CAI	1.0 (0.558)	0.9
Nc	13.8	15.0
tAI	0.4	0.4
Overall G/C content (%)	57.5	57.3
G/C content at 1st place (%)	57.4	57.4
G/C content at 2nd place (%)	47.8	47.8
G/C content at 3rd place (%)	66.9	65.7

CAI: Codon adaptation index; Nc: Effective number of codons; tAI: tRNA adaptation index.