Table 1.

Overall evolution of TB status of farms 1, 2, 3 and 5 throughout 36 months of vaccination trial.

	Month 0	Month 6	Month 12	Month 24	Month 36
Total Census	1255	1387	1335	1345	1506
% TB + animals	44% (33–63)	39% (23–61)*	39% (5–65)*	35% (1–57)**	30% (2–48)**
Attributable fractiona	–	11% (0–32)	11% (0–85)	19% (0–97)	31% (14–94)

^aAttributable Fraction: Percentage of prevalence reduction between prevalence at M0 and the prevalence at subsequent samplings. Ranges are shown in parenthesis. * P < 0,05. ** P < 0,001. Chi square test. Significant differences respect to the initial proportion of positive animals at M0.