Find out why the BCG vaccine leaves a mark on the arm in most people

Photo: Julia Prado/MS

You know that little scar on the arm that almost everyone has? The famous brand is the result of the body’s reaction to the BCG vaccine, which is given to newborns preferably before the baby leaves the maternity ward. Because of this vaccine, serious cases of tuberculosis are extremely rare today.

BCG was developed to prevent severe forms of tuberculosis, a disease that primarily affects the lungs, and is the result of long research by Frenchmen Léon Calmette and Alphonse Guérin. The scientists diluted a bacterium called Bacillus Calmette and Guérin — hence the acronym BCG.

The vaccine is freely available in the SUS, and is usually given on the maternity ward or in health centers soon after the baby is born or as soon as possible. The BCG vaccine is highly effective, especially against the common form of tuberculosis, with a protection rate of 78%.

No scars, no trace?

It is still believed that if the BCG vaccine does not leave a scar on the arm, it is because the vaccination did not work. this is not true. Even in those rare cases when the vaccine does not leave a mark, protection is guaranteed.

In addition, international studies conducted by the World Health Organization (WHO) and analyzes conducted by the Ministry of Health concluded that it is not necessary to apply a booster dose to children between the ages of 6 to 10 years, as was done in Brazil a few years ago.

Source: Ministry of Health