Table 3. Viremia and antibody responses of interferon-α/β/γ receptor–deficient mice experimentally inoculated with Heartland virus*.
| Inoculum dose, PFU | dpi | Mean peak titer† | Mean ELISA titer | ELISA positive, no. (%) | Mean PRNT70 titer‡ | PRNT70 positive, no. (%) |
|---|---|---|---|---|---|---|
| 104 | NA | 8 (1.0) | NA | − | NA | − |
| 104 | NA | − | NA | − | NA | − |
| 103 | 21 | 6.6 (1.2) | 4.1 (2.0) | 1 (50) | NT | − |
| 102 | 28 | 5.3 (2.3) | 3.9 (1.7) | 1 (50) | NT | NT |
| 102 | 32 | − | NT | − | 2.2 (0.4) | 2(100)§ |
| 101 | 28 | 4.6 (2.1) | 3.5 (1.4) | 1 (33) | 1.5 (0.6) | ND |
| 101 | 42 | − | NT | − | 1.3 (0.5) | 1 (33) |
| 100 | 28 | 3.4 (2.2) | 2.7 (1.4) | 1 (9) | 1 | 1 (9) |
| 100 | 42 | − | NT | − | 1.5 (0.6) | 2 (33) |
*Bold indicates initial (not given a booster immunization) sampling of a pair of animals that were later given a booster immunization. dpi, day postinoculation; NA, not applicable because uniform deaths were observed; ND, not detected; NT, not tested; PRNT70, 70% plaque reduction neutralization test; −, not assessed for titer. †Peak titers (log10 PFU/mL of serum) (SD). Detection limit was 1.5 log10 PFU/mL. ‡log10 reciprocal titer (SD). §Tested at 4 d postchallenge.