Table 2. Pig pre- and post-exposure serum antibody titers.
| Pigs infected with: | Antibody titers to challenge virus | |||
| Pre-infection sera | Post-infection sera a | |||
| HI test | VN test | HI test | VN test | |
| Ck/Indo/03 | <10 | <20 | 10–160 (2) | 80–1280 (2) |
| VN/04 | <10 | <20 | 320 (1) | 1280–5120 (1) |
| WS/Mong/05 | <10 | <20 | 10–80 (2) | 80–320 (2) |
| MDk/VN/05 | <10 | <20 | <10 | 20–40 (1) |
| Sw/NC/04 | 10–20 | <20 | 160–320 (2) | 640–2560 (2) |
| Sw/IN/88 | 20 | <20 | 640 (2) | 640–1280 (2) |
a
The number of pigs (of 2) positive for antibodies against the challenge virus is shown in brackets.