How long can the redness and swelling on the arm subside after playing tuberculosis vaccine?

To tell you exactly, there is no such thing as a tuberculosis vaccine.

According to your description, there are two possibilities.

1. The injection position is in the forearm, between the wrist and elbow. That thing is called "PPD"

Generally, the swelling is the most serious in 48-72 hours, which can reflect the infection of tuberculosis in the body and serve as a reference for clinical diagnosis.

The injection site is in the deltoid muscle of the left upper arm, which is called "BCG".

Generally, only children fight. It will break in about 30 days, and it will scab naturally. Don't worry.