Table 1 BCG vaccination studies comparing the use of both one single dose or repeated doses of the vaccine in cattle and wildlife

Red deer ( Cervus elaphus )

2 doses of 2.5×10⁶ cfu BCG Pasteur

8 weeks

Subcutaneous

[5]

Two doses of vaccine were superior to one dose producing protection against infection.

Red deer ( Cervus elaphus )

2 doses of 2×10⁶ cfu BCG Pasteur

6 weeks

Subcutaneous

[18]

Single-dose vaccines protected against disease. Boosting was required to protect against infection.

White-tailed deer ( Odocoileus virginianus )

2 doses of 10⁷ cfu BCG Pasteur

6 weeks

Subcutaneous

[19]

Pathology scores were lower in deer receiving 2 doses of M. bovis BCG compared to unvaccinated ones or those who received a single dose.

Brush-tailed possum ( Trichosurus vulpecula )

12 doses of 1×10⁸; 2 doses of 1×10⁸ cfu BCG Pasteur

1 Week (12 doses); 6 weeks (2 doses)

Intranasal aerosol and conjuntival instillation

[20]

The group vaccinated 12 times showed the greatest level of protection. Revaccination after a period of 6 weeks had no beneficial and no deleterious effects as compared to the protection induced by a single dose of vaccine.

Cattle

2 doses of 10⁶ CFU BCG Pasteur

6 weeks

Subcutaneous

[21]

Significantly less protection than those vaccinated only once. Revaccination reduced the level of protection induced by a single vaccination.