Table 1. Initial relative fitness^a (±s.e.m.) of wt and mt virus.

Virus	Cell type
	MT4	C8166
wt	1.04±0.02	1.02±0.02
mt	0.83±0.02	0.81±0.03

^aFitness is relative to reference strain v13

wt>mt, p<0.0001