Evaluating Oral and Parenteral Vaccines for Wild Boar TB

Twenty 3-4-month-old wild boar piglets were bought in a commercial farm known to be free of mycobacterial lesions at slaughter and with a fully negative ELISA test [35] (link). The animals were housed in class III bio-containment facilities where they had ad libitum food and water. Wild boar piglets were randomly assigned to one of four treatment groups: Group 1, unvaccinated controls; Group 2, parenterally vaccinated with heat-inactivated M. bovis; Group 3, orally vaccinated with heat-inactivated M. bovis; Group 4, orally vaccinated with live BCG. Oral vaccines were delivered in baits designed for wild boar piglets [36] (link). For the challenge, 5 ml of a suspension containing 10⁶ colony forming units (cfu) of an M. bovis field strain were administered by the oropharyngeal route as described in previous experiments [17] (link), [37] (link).
The animals were handled nine times during the experiment, including the vaccination (T1, day 1), the challenge two months after vaccination (T2, day 60), and the necropsy four months after challenge and six months after vaccination (T3, day 189). In addition to T1, T2 and T3, blood samples were taken at days 8, 21, and 49 post-vaccination (p.v), and after challenge at days 74, 83, 104 and 133 p.v.
Handling procedures and sampling frequency were designed to reduce stress and health risks for subjects, according to European (86/609) and Spanish laws (R.D. 223/1988, R.D. 1021/2005). The protocol was approved by the Committee on the Ethics of Animal Experiments of the Regional Agriculture Authority (Diputación Foral de Vizcaya, Permit Number: 2731-2009).