Neutralization response demonstrated by early and late responders. The numbers on the bars are postinfection months. (A) The mean neutralization response (against isolates C-I and C-II) demonstrated by four early responders. SC-9 demonstrated a neutralization response at 2 months and SC-6, SC-20, and SC-30 at 3 months of infection. The neutralization response remained consistent up to 6–10 months; however, the neutralization response could not be studied subsequently due to the nonavailability of samples. (B) The mean neutralization response (against isolates C-I and C-II) demonstrated by three late responders. SC-25 demonstrated a neutralization response at 22 months, which remained consistent up to 44 months. SC-26 and SC-27 demonstrated a neutralization response at 38 and 25 months postinfection, which remained consistent up to 55 months.