TABLE 1.
Virulence of wild-type and mutant TBEV in suckling mice
| Virusa (dilution) | No. of surviving mice/total no. of mice | % Mortality | Avg survival time (days)b |
|---|---|---|---|
| WT (10−5) | 0/9 | 100 | 5.3 ± 0.9 |
| WT (10−7) | 0/6 | 100 | 8.2 ± 1.8 |
| prM(ΔR88) | 23/35 | 34 | 17.6 ± 3.6 |
| prM(ΔR88)-A (10−3) | 1/9 | 89 | 5.4 ± 0.9 |
| prM(ΔR88)-A (10−5) | 5/11 | 55 | 7.3 ± 0.8 |
| prM(ΔR88)-B (10−3) | 0/10 | 100 | 5.0 ± 0.0 |
| prM(ΔR88)-B (10−5) | 2/9 | 78 | 7.7 ± 1.8 |
| prM(ΔR88/Y76C) | 1/11 | 91 | 10.3 ± 3.5 |
| prM(ΔR88/C79Y) | 0/10 | 100 | 8.0 ± 3.8 |
a
WT virus, prM(ΔR88)-A, and prM(ΔR88)-B were mouse brain suspensions; prM(ΔR88), prM(ΔR88/Y76C), and prM(ΔR88/C79Y) were undiluted cell culture supernatants.
b
Data are means ± standard deviations.