What is the BCG vaccination?

What is the BCG vaccination?

• A. BCG is a live attenuated strain of Mycobacterium used to prevent TB; it may cause a false positive PPD
• B. BCG is a killed vaccine for TB and cannot affect PPD
• C. BCG is a toxoid vaccine for TB
• D. BCG is an inactivated virus vaccine for TB

Answer: (A)

BCG vaccination uses a live, attenuated strain of Mycobacterium (M. bovis) to help protect against tuberculosis, especially severe disease in children. Because it’s a live mycobacteria, it can provoke a delayed-type hypersensitivity reaction to tuberculin, leading to a positive PPD test even if there isn’t active TB. This cross-reaction is why a PPD can be falsely positive after BCG. It is not a killed vaccine, a toxoid, or an inactivated virus.

BCG vaccination uses a live, attenuated strain of Mycobacterium (M. bovis) to help protect against tuberculosis, especially severe disease in children. Because it’s a live mycobacteria, it can provoke a delayed-type hypersensitivity reaction to tuberculin, leading to a positive PPD test even if there isn’t active TB. This cross-reaction is why a PPD can be falsely positive after BCG. It is not a killed vaccine, a toxoid, or an inactivated virus.