How long does it take BCG to become effective?

BCG (Bacillus Calmette-Guérin) vaccine typically takes about 6 to 8 weeks after administration to become effective in providing protection against tuberculosis. However, the exact time can vary based on individual immune responses. It's important to note that while the vaccine can help reduce the risk of severe TB, it does not guarantee complete immunity. Regular screenings and preventive measures are still essential for those at risk.