BCG Vaccine Injection

• Full Name: Bacillus Calmette–Guérin (BCG) Vaccine

• Type: Live attenuated bacterial vaccine

• Form: Injectable solution, usually given intradermally (just under the skin).

How It Works

• Contains a weakened strain of Mycobacterium bovis, a bacterium closely related to Mycobacterium tuberculosis.

• Stimulates the immune system to recognize and fight tuberculosis (TB) bacteria.

• Helps develop cell-mediated immunity, which is important for controlling TB infection.

Common Uses

• Prevention of severe forms of tuberculosis in children, such as:

  • TB meningitis

  • Miliary TB (spread throughout the body)

• Sometimes used as immunotherapy for bladder cancer (given directly into the bladder, not as an injection).

When It Is Given

• Usually administered to newborns or infants in countries where TB is common.

• Given as a single dose on the upper arm.

Advantages

• Reduces the risk of severe, life-threatening TB in children.

• Provides partial protection against pulmonary TB (effectiveness varies by region).

• Long-lasting immunity, though booster doses are generally not recommended.

Possible Side Effects

• Small red bump at injection site (normal)

• May develop into a small ulcer or scar (a sign of immunity)

• Swollen lymph nodes near the injection site (rare)

• Very rare: severe allergic reaction, disseminated BCG infection (mainly in people with weak immune systems)

Precautions

• Not recommended for people with:

  • Severe immune suppression (HIV, cancer chemotherapy, congenital immunodeficiency)

  • Generalized skin infections at injection site

• Should be given only by trained healthcare professionals, as incorrect injection can cause complications.

• Pregnant women usually do not receive this vaccine.