Table 2. Serologic responses in 3 infected alpacas, as measured by virus neutralization tests and Luminex bead assays for selected sample days*.
| Dpi | Serologic results |
No. positive/no. tested)§ |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| VNT titer† |
Luminex assay MFI‡ |
|||||||||
| Alpaca 1 | Alpaca 2 | Alpaca 3 | Alpaca 1 | Alpaca 2 | Alpaca 3 | VNT | Luminex | |||
| 0 | Negative | Negative | Negative | 787 | 889 | 167 | 0/3 | 0/3 | ||
| 3 | Negative | Negative | Negative | 373 | 814 | 152 | 0/3 | 0/3 | ||
| 5 | Negative | Negative | Negative | 418 | 945 | 223 | 0/3 | 0/3 | ||
| 7 | Negative | Negative | Negative | 272 | 932 | 249 | 0/3 | 0/3 | ||
| 10 | Negative | 1:40 | Negative | 478 | 2,869 | 58 | 1/3 | 1/3 | ||
| 12 | Negative | 1:40 | Negative | 928 | 10,274 | 331 | 1/3 | 1/3 | ||
| 14 | Negative | 1:40 | Negative | 1,041 | 7,658 | 899 | 1/3 | 1/3 | ||
| 21 | 1:10 | 1:40 | Negative | 877 | 6,893 | 629 | 1/3 | 1/3 | ||
| 24 | 1:20 | 1:20 | Negative | 1,506 | 3,324 | 678 | 2/3 | 1/3 | ||
| 26 | 1:20 | 1:20 | Negative | 853 | 4,161 | 667 | 2/3 | 1/3 | ||
| 28 | 1:20 | 1:20 | Negative | 773 | 4,682 | 724 | 2/3 | 1/3 | ||
| 31 | 1:20 | 1:40 | Negative | 548 | 11,259 | 649 | 2/3 | 1/3 | ||
| 33 | 1:10 | 1:20 | Negative | 688 | 6,090 | 455 | 1/3 | 1/3 | ||
| 35§ | 1:10 | NA | Negative | 510 | NA | 586 | 0/2 | 0/2 | ||
*Bold indicates positive results. Gray shading indicates that >1 animal was positive for the sample collected on that day. Dpi, day postinfection for challenge (initial infection); MFI, median fluorescent intensity; VNT, virus neutralization test. †The starting dilution was 1:10, and the threshold for a positive result was a dilution of >1:20. ‡The MFI threshold for a positive result for the Luminex assay was 2,500. §Alpaca 2 was euthanized at day 33, leaving only 2 animals in the study at day 35.