These techniques allowed researchers to develop reliable and effective vaccines– first for smallpox, and again in 1921, when scientists developed the BCG vaccine to battle TB.

研究人员这些技术研制出了可靠、有效疫——首先是针对天花，然后在 1921 年，科学家又研发出了卡，于对抗肺结核。

And this is a pretty useful feature of IGRAs since BCG vaccine is given to a lot of children around the world to prevent disseminated TB.

这是IGRA有种特性，因为世界上多小孩都接种过卡，预防TB在体内播散。

Importantly, BCG is massively scalable and has a safety profile that's among the best of any reported vaccine.

重要是，卡可大规模生产，并且它安全性在所有有记录疫中是最好。

Also, the IGRA is more specific to TB rather than other types of mycobacterial infections and is unlikely to be positive as a result of having BCG vaccine in the past, a vaccine that protects against TB.

而且IGRA对于TB说有更高准确性，而不会对其它类型分枝杆菌感染出现反应，且IGRA并不会对于曾经接种过卡患者出现阳性反应；卡是种抵抗肺结核疫。

We are repurposing the BCG vaccine, which had been used against TB for almost a century.

我们正在重新利卡，这种疫在近个世纪前就被预防结核病。

A 100-year-old vaccine, the BCG, has helped, but it's only partially effective.

种百年历史疫——卡，已经发挥了作，但它仅部分有效。

Together, in heart and mind, in the prevention of tuberculosis by the BCG vaccine.

同心协力，以卡预防结核病。