Tuberculosis vaccination sequence effect on protection in wild boar

Area of Science:

• Veterinary Immunology
• Wildlife Disease Ecology
• Bacteriology

Background:

• Eurasian wild boar (Sus scrofa) act as reservoirs for tuberculosis (TB).
• Vaccination strategies are crucial for controlling TB transmission in wild boar populations.
• Understanding the efficacy of different vaccination regimens is essential.

Purpose of the Study:

• To evaluate the protective immunity and immune response elicited by homologous and heterologous vaccination regimens in Eurasian wild boar against TB.
• To compare the efficacy of BCG and heat-inactivated Mycobacterium bovis (IV) vaccines administered in different sequences.

Main Methods:

• Twenty-one wild boar piglets were randomly assigned to five groups: Control, homologous BCG, homologous IV, heterologous IV-BCG, and heterologous BCG-IV.
• Animals were challenged with Mycobacterium bovis, and lesion scores were assessed to determine protection.
• Immune responses were evaluated, though not detailed in the abstract.

Main Results:

• Homologous IV (IVx2) and heterologous IV-BCG regimens significantly reduced total lesion scores by 67% and 66%, respectively, compared to controls.
• Homologous BCG showed a 48% reduction in lesion score, while BCG-IV showed only a 3% reduction, with no statistical significance.
• Heterologous regimens did not offer superior protection compared to homologous ones and yielded variable results.

Conclusions:

• Homologous vaccination, particularly with heat-inactivated Mycobacterium bovis (IV), is the most effective strategy for vaccinating wild boar against TB.
• The sequence of vaccine administration significantly influences the outcome, highlighting the importance of prior sensitization.
• Further research into the impact of prior sensitization on vaccination outcomes is warranted.