 Pseudotyped clade C viruses were partitioned into three infection stage groups according to their sequential gain of HIV-0 specific antibody responses as a marker of time from infection; pre-seroconversion (Ab-) (n = 00) indicated in blue, indeterminate (Ab-/+) (n = 00) indicated in grey and post-seroconversion (Ab+) (n = 00) indicated in red. Each point represents the geometric mean of viruses tested for neutralization sensitivity using 