Table 1.

The research of revaccinating BCG to protect against tuberculosis.

Authors (Countries)	Study Design	Results
Christopher Dye South Africa	9290 new cases observed in a cohort	(1) Reduce the likelihood of TB transmission (2) Risk of infection falling from 5.7% to 4.8% per year (3) Cost-effectiveness: about twice as cost-effective as preventing transmission
Rakshit S, Ahmed A, Adiga V, Sundararaj BK, Sahoo PN, Kenneth J, et al. India	Two hundred healthy adults, BCG vaccinated at birth, were tested for their IFN-γ release assay (IGRA) status. Of these, 28 IGRA+ and 30 IGRA– were BCG revaccinated, and 24 IGRA+ and 23 IGRA– subjects served as unvaccinated controls.	(1) IFN-γ and/or IL-2 Ag85A- and BCG-specific CD4+ and CD8+ T cell responses were boosted by revaccination at 4 and 34 weeks (2) CD4+ T cells expressing up to 8 cytokines were also significantly enhanced in both IGRA+ and IGRA- vaccinees relative to unvaccinated controls, most markedly in IGRA+ vaccinees. (3) Compared with control group, the innate IFN-γ+ NK/γδ/NKT cell responses were higher in both IGRA+ and IGRA- vaccinees. (4) the immunogenicity of BCG was not affected even in patients with LTBI
Nemes E, Geldenhuys H, Rozot V, et al. South Africa	Randomized, three-arm, placebo-controlled, partially-blinded clinical trial aimed to enroll 990 healthy, HIV-uninfected, QFT-negative, 12- to 17-year-old adolescents, BCG- vaccinated in infancy	An effectiveness of 45.4% for continuous QFT conversion by BCG reinoculation