Fig. 2.
Transmitter and recipient viruses are resistant to plasma neutralizing antibodies of transmitters circulating at transmission. The 50 % neutralization titer (NT50, i.e., the reciprocal plasma dilution yielding 50 % neutralization) for a transmitter, b recipient and c SF162 Env-pseudoviruses against transmitter (red) and recipient (blue) plasma samples, respectively. Off-antiretroviral treatment (ART) plasma samples tested were from time points before the estimated date of transmission (EDT) (only for transmitter plasma), closest to the EDT or after the EDT. Due to differences in ART initiation and limitations in sample availability, plasma sample time points and virus combinations are not identical for each probed individual. NT50 values were derived from 2 independent experiments each performed in duplicates. SF162 was included as a Tier-1 neutralization sensitive virus. The dotted line indicates the threshold for NT50 determination as the highest plasma concentration tested was 1:40 and values below the threshold were given an arbitrary value of 30. For detailed NT50 values and for plasma sample time points see Additional file 8: Table S3 and Additional file 2: Figure S2, respectively