Over 56% of the test candidates involved had been vaccinated with BCG 12 months previously.
Unfortunately, it is not clear from the study what the distribution of the reduced immune response to the previous vaccination is.
A reduced response of the toll like receptors is even desired on certain time!
For this reason it would be interesting, how it looks 2 or 3 months after the 2nd vaccination?
Unfortunately, there is no data on this either.
Therefore, as an absolute layman, I can not classify this study as very questionable.