Figure 2From: Longitudinal field studies reveal early infection and persistence of influenza A virus in piglets despite the presence of maternally derived antibodiesPrevalence of IAV antibodies at the different sampling times of both sows and piglets of the three herds. The columns present the proportion of IAV seropositive sows 2 weeks before farrowing and seropositive piglets at weeks 3 and 10–12.Back to article page