Table 3.
Immunogenicity and protective activity of ACAM1000 and Dryvax® in mice and monkeys.
| Study | Species (strain) | Vaccine (8 log10 pfu/mL) | No. animals | Immune response |
Challenge | Survival | |||
|---|---|---|---|---|---|---|---|---|---|
| Cutaneous pock N (%) | Neutralizing antibody N (%) | Neutralizing antibody titera | IFN-γ secreting cells × 10−61 | ||||||
| 1 | Mouse (Balb/c) | ACAM1000 | 10 | –b | 10 (100%) | 53 | – | Cowpox 10 LD50 INc | 10/10 (100%) |
| Dryvax® | 9 | – | 5 (56%) | 14 | – | 7/7 (100%) | |||
| Sham | 5 | – | 0 (0%) | <10 | – | 0/5 (0%) | |||
| 2 | Mouse (Balb/c) | ACAM1000 | 5 | – | – | – | – | Vaccinia WR 100 LD50 INd | 5/5 (100%) |
| Dryvax® | 5 | – | – | – | – | 5/5 (100%) | |||
| Sham | 5 | – | – | – | – | 0/5 (0%) | |||
| 3 | Mouse (Balb/c) | ACAM1000 | 5 | – | 5 (100%) | 92 | 1450 | ||
| Dryvax® | 5 | – | 3 (60%) | 20 | 1052 | ||||
| Sham | 5 | – | 0 (0%) | <20 | 0 | ||||
| 4 | Mouse (Balb/c) | ACAM1000 | 4 | – | – | – | – | Ectromelia 4.3 log10 pfu aerosol | 4/4 (100%) |
| Dryvax® | 4 | – | – | – | – | 4/4 (100%) | |||
| Sham | 4 | – | – | – | – | 0/4 (0%) | |||
| 5 | Monkey (rhesus) | ACAM1000 | 6 | 6 (100%) | 5 (83%) | 18 | – | ||
| Dryvax® | 6 | 6 (100%) | 4 (67%) | 25 | – | ||||
a
Geometric mean.
b
– = not tested.
c
5 weeks after vaccination.
d
3 weeks after vaccination.