Table 2A. The passive immunizing protection assay (in vivo).
| Group NO. | Serum dose(U/mouse) | serum dilution fold | No.of survival | Total | survival ratea |
|---|---|---|---|---|---|
| 1–1 | 12.00 | 0 | 8 | 8 | 100.00% |
| 1–2 | 3.00 | 4 | 7 | 8 | 87.50% |
| 1–3 | 0.75 | 16 | 5 | 8 | 62.50% |
| 1–4 | 0.19 | 64 | 2 | 8 | 25.00% |
| 1–5 | 0.09 | 128 | 0 | 8 | 0.00% |
a Survival rate of pups born to immunized dams after lethal viral challenge. Estimation of 50% effective dose (ED50). (50.0–25) ÷ (62.50–25.00) = 25 ÷ 37.5 = 0.67; (−0.125)–(−0.72) = 0.595;∴0.595*0.67 = 0.39865; Antilog of (−0.72 + 0.39865) = Antilog of −0.32135; ED50 = 0.477 U.