Table 1. Amino acid sites that differ between the Caribbean B strains and the subtype B reference strains.

Gene	Location	Mutation	Caribbean B	Reference B	p
gag			(n = 25)	(n = 19)
	matrix	D102E	23	11	0.01
	capsid	I159V	9	15	0.005
pol			(n = 14)
	signal peptide	N21TDA	8	18	0.03
	protease	K97R	1	13	0.0004
rev			(n = 14)
		V102I	2	13	0.002
env			(n = 14)
	V3 loop	T319-	5	0	0.008
	C5	N474D	5	15	0.01
	C5	K476RM	5	17	0.002