Table 5.
Protective efficacy of live or inactivated chimeric LGT/DEN4 viruses tested in mice
| Immunizing virus | Dose of immunization (PFU) | ELISA mean antibody titer | Mean neut. antibody titer | Mortality after i.p. challenge with 1,000 i.p. LD50 of TP21 |
|---|---|---|---|---|
| E5/DEN4 | 10 | 240 | 52 | 0/5 |
| 103 | 200 | 52 | 1/5 | |
| 105 | 1,530 | 151 | 0/5 | |
| E5/DEN4 | 10* | <100 | <20 | 4/5 |
| (UV) | 103* | <100 | <20 | 4/5 |
| 105* | 100 | <20 | 4/5 | |
| TP21/DEN4 | 10 | 240 | 65 | 1/5 |
| 103 | 280 | 174 | 0/5 | |
| 105 | 3,680 | 257 | 0/5 | |
| TP21/DEN4 | 10* | <100 | <20 | 5/5 |
| (UV) | 103* | <100 | <20 | 5/5 |
| 105* | <100 | <20 | 3/5 | |
| TP21 | 10 | 6,400 | 528 | 0/2 |
| E5 | 10 | 6,400 | 536 | 0/3 |
| DEN4 | 105 | <100 | <20 | 5/5 |
| Control | NA | <100 | <20 | 5/5 |
*
Titer before UV irradiation that completely inactivated infectivity.