Effect of maternally derived antibodies on the clinical signs and immune response in @entity1707 after primary and secondary XXXX with an influenza H1N1 virus.

@entity1707 @entity281 @entity1865
The aim of this study was to determine the role of maternally derived antibodies ( @entity1865 ) against an influenza H1N1 virus in the clinical protection of piglets and especially their effect on the development of the active immunity after an @entity281 with a homologous influenza H1N1 virus. Twenty piglets with @entity1865 and 10 piglets without @entity1865 were housed together and inoculated twice with influenza H1N1 virus, at 7 and 15 weeks of age. Nine piglets without @entity1865 were added to these groups at 12 weeks of age to be inoculated at 15 weeks of age only. Clinical signs, body temperature, growth performance, virus excretion, antibody responses, and influenza-specific T-cell response were monitored. It was shown that @entity1865 protect piglets against the clinical consequences of a primary @entity281 , but that this protection is not complete. A short but significant rise in body temperature was observed and growth seemed to be inhibited due to the @entity281 . Piglets with @entity1865 shed virus for a longer period after an @entity281 than piglets without @entity1865 . Piglets with and without @entity1865 were protected against the clinical consequences of a secondary @entity281 . However, both after primary and secondary @entity281 significant differences in immune responses were observed that indicated that @entity1707 with @entity1865 developed a weaker immunity than @entity1707 without @entity1865 . Furthermore, overall growth performances from weaning to slaughter show a trend in favour of @entity1707 without maternal antibodies, compared to @entity1707 with maternal antibodies, mainly caused by a significant better performance in the second half of the finishing period. The results of this study provide us insight in the role of @entity1865 in clinical protection and their influence on active immunity after an influenza virus @entity281 of @entity1707 . Furthermore, it leads us to the discussion about the profitability of massive sow herd vaccinations in an attempt to increase @entity1865 levels in piglets, taking into account the overall performance of these piglets and the possible effects on antigenic drift.
