nor the feed intake (as measured by body weight at 3 or 7 weeks
post vaccination in the field studies) of the animals was affected, this
transient increase of rectal temperature can be considered to be an
acceptable vaccine related finding. This notion is supported by the
fact that an average increase of 1C is well within the limit of 1.5C
that is allowed according to European Pharmacopoeia monograph
2448 (porcine enzootic pneumonia vaccine (inactivated)).
The experimental challenge studies indicate that the onset of
immunity occurs as early as 2 weeks (PCV2) to 4 weeks (M. hyopneumoniae)
post vaccination and lasts for at least 21 (M. hyopneumoniae)
to 22 (PCV2) weeks. This was demonstrated by a
significant reduction of the PCV2 viral load in lymphoid organs
and lungs and a significant reduction of M. hyopneumoniae specific
lung lesions. Accordingly, a single vaccination of animals at 3
weeks of age may protect fattening pigs against PCV2 and M. hyopneumoniae
infections during the production life cycle.