Table 2. Long-term antibody response of CD46-IFNAR mice to immunization with MV-EDIII-ectoM.
| Injectionsa (time, months) | Time of sera collection (months) | MV Ab Titerb | DV-1 Ab Titerb | DV-1 rEDIII Titerb | Anti-DV1 FRNT50c | Anti-DV1 FRNT75d |
| MV-EDIII-ectoM (0) | 1 | 15,000 | <100 | ≤ 100 | nd | nd |
| MV-EDIII-ectoM (1) | 2 | 40,000 | 1,600 | 400 | 40 | 10 |
| 3 | 30,000 | 1,000 | 600 | 40 | 10 | |
| 5 | 20,000 | 500 | 100 | 40 | 10 | |
| rEDIII-ectoM (6) | 7 | 20,000 | 20,000 | 100,000 | 1600 | 200 |
| 9 | 10,000 | 2,000 | 10,000 | 320 | 40 | |
| DV1 inoculation (9) | 10 | 10,000 | 200,000 | 800,000 | 32,000 | 4,000 |
a
CD46-IFNAR mice were inoculated intraperitoneally (i.p.) twice with 104 TCID50 of MV-EDIII-ectoM at one month of interval. At 6 months, mice were boosted with 10 µg of recombinant DV1 rEDIII-ectoM protein (from S2 cells) in Alugel adjuvant. At 9 months, mice were inoculated with 107 FFU of DV-1 FGA/NA d1d. bDetermined by ELISA on pooled heat-inactivated sera collected one month after immunizations or DV infection. cFRNT50 represents the highest serum dilution that reduced the number of DV focus-forming units (FFU) on Vero cells by at least 50% and dFRNT75 by at least 75%.