Injecting a TB vaccine into the blood, not the skin, boosts its effectiveness
The BCG vaccine is notoriously bad at preventing the most common form of tuberculosis
PET-CT scans of rhesus monkey lungs show spots of TB infection and tissue inflammation (red and orange). Monkeys that received a TB vaccine intravenously (bottom) were better protected than those who received it just under the skin (top).
University of Pittsburgh School of Medicine