Table 1.

Anti-S. typhi Ty2 LPS responses in serum following primary and booster oral immunizations with live attenuated typhoid vaccine in healthy adults

Immunization (day)VolunteerSerum IgG anti-Ty2 LPSSerum IgA anti-Ty2 LPS
Baseline titerPeak titerResponseaBaseline titerPeak titerResponsea
Primary (1)84.6911.17+0.532.53+
101.572.200.470.73
1110.7644.41+2.667.66+
132.2059.14+1.5110.88+
150.2317.33+0.195.74+
Booster (418)88.5513.280.541.01
1110.8816.051.993.95
150.111.04+0.090.55+
  • a A significant response (+) is defined as a ≥2-fold increase in antibody titers. −, no response.