so no effective TB vaccine.

instead people injected with BCG might get positive skin tests, thus trouble. for example, me. ever since i came to the US, i had to take several chest x-rays to clear suspicion. docs, though, thought i was infected with latent TB and always recommended treatment. i declined, though, for fear of side effects to liver. i might change mind later.

there's effective treatment for TB, unless the unlucky guy got the drug-resistant superbug.

so to your Q, better do nothing, unless you are sure the destination in china is an underdeveloped place, where active TB patients are common.

like HBV, most TB infected chinese are latent ones, no danger of air-air transmission