The tuberculosis morbidity rate in BGC-unvaccinated infants is 18 times greater than that in BCG-vaccinated infants and 6 times higher than the rate of complications due to BCG vaccination. If a scar due to BCG vaccination is absent or 1-2 mm, the tuberculosis morbidity in children of 3 years of life is 7 times higher than when a 3-mm or more scar has formed after vaccination. The technological failures are main causes of complications due to BCG vaccination. The type of a vaccine (BCG-1 or BCG-M) does not play a substantial role in the development of complications.