3.2. Challenge studies
No clinical abnormalities that could be related to treatment
were present in the periods between vaccination and challenge.
However, some vaccinated and control pigs had lameness during
the studies, most likely due to a Streptococcus suis infection, and
in total eight vaccinates and six controls had to be euthanized for
animal welfare reasons. The PCV2 challenge infection did not result
in any clinical signs, but the qPCR data clearly showed infection of
the various lymphoid tissues and lung (Fig. 1). Mean viral loads
were in general in the order of 2-3 log10 lower in the vaccinated
pigs, and the differences between the groups were statistically significant
(p < 0.05). Vaccination also resulted in a significantly