Neutralizing activity of sequential serum samples.

aTitres are expressed as the reciprocal dilution of serum required to reduce infectivity by ≥90% (IC90) compared to pooled HIV ve- serum control. bSerum samples collected from the indicated days after onset of symptoms characteristic of PHI. Time-points from which envs were cloned are underlined. cThe development of autologous Nabs was assessed against the envs cloned from acute infection (days 6–32), as previously reported [16], [27]. d<10, less than 90% reduction of infection was observed at the highest serum input tested (1∶10 dilution). ent, not tested. f*, A clear autologous Nab response had developed by day 405, but it only achieved ∼80% reduction of infection at the highest serum input assayed (1∶10 dilution).