Figure 5.

Serological follow-up of PRRSv-specific antibodies in unvaccinated, control piglets born from PRRSv-vaccinated seropositive sows (E+ piglets) and PRRSv-vaccinated seronegative sows (E− piglets) in two Belgian farrow-to-finish herds. Piglets in herd 1 (A–C) were sampled at 3, 6 and 11 weeks of age. Piglets in herd 2 (D–F) were sampled at 4, 7 and 12 weeks of age. All piglets were analyzed using IDEXX ELISA (A + D; ELISA 1), CIVTEST ELISA (B + E; ELISA 2) and virus neutralization assay (C + F; VN). Individual S/p values (ELISA 1), IRPC values (ELISA 2) and Log₂ VN titers are shown as dots with lines connecting the values at each sample moment for each piglet. Cut-off values for seropositivity are included in each graph as a dotted horizontal line.