Passively acquired maternal derived immunity (MDI) is a double-edged sword, according to Meggan Bandrick and colleagues at the University of Minnesota in a paper in BMC Veterinary Research.

They explain that maternal derived antibody-mediated immunity (AMI) and cell-mediated immunity (CMI) are critical immediate defences for the neonate. However, MDI may interfere with the induction of active immunity in the neonate, i.e. passive interference.

The effect of antigen-specific MDI on vaccine-induced AMI and CMI responses to Mycoplasma hyopneumoniae (M. hyopneumoniae) was assessed in neonatal piglets. To determine whether CMI and AMI responses could be induced in piglets with MDI, piglets with high and low levels of maternal M. hyopneumoniae-specific immunity were vaccinated against M. hyopneumoniae at seven days of age. Piglet M. hyopneumoniae-specific antibody, lymphoproliferation and delayed type hypersensitivity (DTH) responses were measured seven and 14 days post-vaccination.

Piglets with M. hyopneumoniae-specific MDI failed to show vaccine-induced AMI responses; there was no rise in M. hyopneumoniae antibody levels following vaccination of piglets in the presence of M. hyopneumoniae-specific MDI. However, piglets with M. hyopneumoniae-specific MDI had primary (antigen-specific lymphoproliferation) and secondary (DTH) M. hyopneumoniae-specific CMI responses following vaccination.

From their study, Bandrick and colleagues concluded that neonatal M. hyopneumoniae-specific CMI is not subject to passive interference by MDI. Furthermore, they added, it appears that both maternal derived and endogenous CMI contribute to M. hyopneumoniae-specific CMI responses in piglets vaccinated in the face of MDI.

Reference

Bandrick M., K. Theis and T.W. Molitor. 2014. Maternal immunity enhances Mycoplasma hyopneumoniae vaccination induced cell-mediated immune responses in piglets. BMC Veterinary Research. 10:124. doi:10.1186/1746-6148-10-124

July 2014