TABLE 3.
Detection of PRRSV-specific antibodies in experimentally infected pigsa
| Infection | Pig no. | Seroconversion (ELISA/IPMA result) on day postinfection:
|
|||
|---|---|---|---|---|---|
| 0 | 7 | 14 | 21 | ||
| Cloned virus | 1 | −/0 | −/0 | +/1,250 | +/6,250 |
| 2 | −/0 | +/50 | +/1,250 | +/6,250 | |
| 3 | −/0 | +/50 | +/250 | +/6,250 | |
| 4 | −/0 | +/0 | +/6,250 | +/6,250 | |
| Parental virus | 5 | −/0 | +/250 | +/6,250 | +/6,250 |
| 6 | −/0 | +/0 | +/1,250 | +/6,250 | |
| 7 | −/0 | +/0 | +/1,250 | +/6,250 | |
| 8 | −/0 | +/0 | +/1,250 | +/6,250 | |
| None (negative control) | 9 | −/0 | −/0 | −/0 | −/0 |
| 10 | −/0 | −/0 | −/0 | −/0 | |
| 11 | −/0 | −/0 | −/0 | −/0 | |
| 12 | −/0 | −/0 | −/0 | −/0 | |
a
Seroconversion was assayed by blocking ELISA and immunoperoxidase monolayer assay (IPMA), two tests routinely used for large-scale examination of field serum samples at the Danish Veterinary Institute. ELISA results: −, no anti-PRRSV antibodies detected; +, anti-PRRSV antibodies detected. Immunoperoxidase assay: sera were tested at 1:50, 1:250, 1:1,250, and 1:6,250 dilutions; 0, negative (anti-PRRSV antibodies not detected); positive results are indicated as the reciprocal of the highest serum dilution at which anti-PRRSV antibodies could be detected.