The Story Behind a Common Scar: What Is the BCG Vaccine?

The image above shows a small, circular scar on a person’s upper arm. The text states that millions of people around the world realize they have the exact same scar. This is a very common observation. The scar is the result of the BCG vaccine, which is given to protect against tuberculosis.

What Is the BCG Vaccine?

The BCG vaccine stands for Bacillus Calmette-Guérin. It is a vaccine primarily used against tuberculosis. Tuberculosis is a bacterial infection that usually affects the lungs but can affect other parts of the body. The vaccine is made from a weakened strain of the bacteria that causes tuberculosis in cattle. It does not cause the disease in humans, but it helps the immune system recognize and fight the real infection.

Why Does It Leave a Scar?

The BCG vaccine is typically injected into the skin of the upper arm. After the injection, a small bump may form. Over the next few weeks, the bump can turn into a small blister or ulcer. This is a normal reaction. The area then heals and leaves a small, permanent scar. The presence of the scar is often used as a sign that the vaccine was successfully administered.

Who Gets the BCG Vaccine?

The BCG vaccine is not routinely given to everyone. It is usually given to infants and children in countries where tuberculosis is common. It is also given to healthcare workers and people who are at high risk of exposure to the disease. In countries where tuberculosis is rare, the vaccine is not typically part of the standard vaccination schedule.

The Bottom Line

The small, circular scar on the upper arm is a common sight for millions of people. It is the result of the BCG vaccine, which protects against tuberculosis. It is a sign of public health efforts to prevent a serious disease. If you have this scar, you are part of a global community that has been protected against tuberculosis.

Do you have this scar? Share your thoughts in the comments below.