Table 7.

Calculation of viral safety margins

	HIV	HCV	HBV	HAV	Parvovirus
Viral load (log; from Table 1)	5.7	6.0	4.4	2.9	6.6
Fibrinogen
Viral clearance capacity (log)	17.5	17.5	15.5	10.3	6.8
Safety margin (fold)	6.3 × 1011	3.2 × 1011	1.3 × 1011	2.5 × 107	1.6
Risk/vial (with virus at maximum load)*	3 × 10−16	5 × 10−16	1 × 10−15	7 × 10−12	1 × 10−4
Adjusted risk/vial (all lots)†	1 × 10−19	3 × 10−19	5 × 10−17	2 × 10−16	2 × 10−6
Thrombin
Viral clearance capacity (log)	18	19	17	11	7.3‐9.9
Safety margin (fold)	2 × 1012	1 × 1013	4 × 1012	1 × 108	2 × 103
Risk/vial (with virus at maximum load)‡	8 × 10−18	2 × 10−18	4 × 10−18	1 × 10−13	3 × 10−6‐8 × 10−9 §
Adjusted risk/vial (all lots)†	4 × 10−21	8 × 10−22	2 × 10−19	3 × 10−18	7 × 10−8‐2 × 10−10 §

^* Assumes 1 vial per L of plasma.

^† The risk was adjusted to include lots without virus (calculated from Table 1, Column 4) and further assumes that the average viral load of contaminated lots is 1 log lower than the maximum load.

^‡ Assumes 10 vials per L of plasma.

^§ The larger number applies to Baxter's thrombin and the smaller number applies to Omrix's thrombin.