Table 6.
Estimated viral elimination when processing fibrinogen and thrombin: based on both Omrix's and Baxter's processes
| Step | Log reduction | |||||
|---|---|---|---|---|---|---|
| HIV | HCV | HBV | HAV | Parvovirus B19 | ||
| Fibrinogen | ||||||
| Cryoprecipitation + Al(OH) or wash | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 | |
| Immune neutralization | 3* | 3* | ||||
| S/D treatment | >6 | >6 | >6 | 0 | 0 | |
| Heat treatment | >6 | >6 | >6 | >5.8 to >6.5† | 1.3 | |
| Greater heat sensitivity of B19 than CPV | 1 | |||||
| Reserve capacity of virucidal methods‡ | 4 | 4 | 2 | 0 | 0 | |
| Sum: | 17.5 | 17.5 | 15.5 | 10.3‐11.5 | 6.8 | |
| Thrombin | ||||||
| Cryo removal | 1 | 1 | 1 | 1 | 1 | |
| Immune neutralization | 0 | 0 | 0 | 0 | 0 | |
| Initial fractionation (Baxter)§ | 2 | 2 | 2 | 2 | 2 | |
| Chromatographic purification | 3 | 3 | 3 | 3 | 3 | |
| S/D treatment | >6 | >6 | >6 | 0 | 0 | |
| S/D reserve capacity | 4 | 4 | 2 | NA | NA | |
| Heat treatment (Baxter) | >6 | >6 | >6 | 6.9 | 1.3 | |
| Nanofiltration (Omrix) | >4.4 | >5.3 | >5.5 | 7 | 5.9 | |
| Sum: | 18‐22 | 19‐22 | 17.5‐20 | 11‐13 | 7.3‐9.9¶ | |
*
Virus neutralization is predicated on the fibrinogen containing antibody.
†
The lower number applies to Omrix's fibrinogen and the higher number applies to Baxter's fibrin.
‡
The reserve capacity of vapor treating is estimated at zero since most of the reported viral kill takes place prior to initiating the heat cycle. The estimate of HBV reserve capacity with S/D treatment comes from studies with duck HBV added to whole plasma.
§
A mean of 2 log removal during cold alcohol fractionation is assumed.
¶
The lower number applies to Baxter's thrombin and the higher number applies to Omrix's thrombin.
NA = not applicable.