Table 2. Nymphal tick infection in vaccine field studies in 1998–1999 and 2001–2002
No. of I. scapularis nymphs infected with B. burgdorferi assayed by PCR
1999 sites 2002 sites
Vaccine for P. leucopus 1 2 3 4 5 6
Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg. Pos. Neg.
GST 90 315 57 89 127 224 57 56 93 221 94 168
OspA 87 288 49 121 96 241 41 71 76 178 67 193
OR (95% CI) 1.06 (0.76-1.48) 0.63 (0.39-1.04) 0.70 (0.5-0.98) 0.57 (0.32-0.99) 1.01 (0.69-1.48) 0.62 (0.42-0.92)
C—M—H OR 0.81 (0.65-0.99) P = 0.04 0.75 (0.59-0.95) P = 0.02
  • Pos., positive; Neg., negative.