PRRSV-specific IPMA antibody titers (log₂) (upper panel) and VN antibody titers (log₂) (lower panel) after vaccination and challenge for group H (Mock-vaccinated control), I (Alhydrogel adjuvant) and J (Suvaxyn o/w adjuvant)  = primo vaccination,  = booster vaccination and  = challenge. Symbols represent individual animals and lines represent mean IPMA or SN titers for each group. The dashed line gives the mean titers for group H. The dotted line gives the detection limit for the IPMA or SN test.