Figure 4.

Efficacy of the vaccines containing the F₈ and F₁₀ haptens against alfentanil and acetylfentanyl, respectively. Rats immunized with control, F₁–CRM, or F₈–CRM were challenged with 0.25 mg/kg alfentanil, subcutaneous (s.c.) (A–C); and rats immunized with control, F₁–CRM, or F₁₀–CRM were challenged with 1.0 mg/kg acetylfentanyl s.c. (D–F). Rats were monitored at 15 min intervals for: (A,D) antinociception by latency to respond on a hot plate; (B,E) oxygen saturation (%); and (C,F) heart rate measured by pulse oximetry. Data are expressed as mean ± SEM. Below the graphs, significance of each vaccine group vs CRM control is indicated compared to control at each time point. Symbols and statistics: exact p-values are listed for 0.05 ≤ p ≤ 0.1, and “–” indicates no significant difference, 0.10 ≤ p.