Written by The BCG vaccine is a vaccine against tuberculosis (TB). It is named after its inventors, Albert Calmette and Camille Guérin. The vaccine is made from a weakened strain of TB bacteria. When injected into the skin, the vaccine helps the body develop immunity to TB.
The BCG vaccine is not widely used in the United States because of the low risk of TB in this country. However, it is often given to infants and small children in other countries where TB is common. The vaccine is also recommended for people who are at high risk of TB, such as health care workers and people who live with someone who has TB.
The BCG vaccine is not 100% effective. It is estimated to be about 70% effective in preventing severe forms of TB, such as TB meningitis and miliary TB. The vaccine is less effective in preventing TB that affects the lungs in adults.
The BCG vaccine is given as a single injection into the skin. It is usually given on the upper arm or the back. The vaccine may cause a small sore at the injection site that can be red, swollen, and tender. The sore usually heals within a few weeks.
In some people, the BCG vaccine can cause a more serious reaction, such as a skin infection or a lump under the skin. These reactions are rare.
If you are considering the BCG vaccine, talk to your doctor about the risks and benefits.
Here are some additional things to know about the BCG vaccine:
- The BCG vaccine is not recommended for people who are allergic to the vaccine or its components.
- The BCG vaccine can interfere with the results of the tuberculin skin test (TST). The TST is a test used to screen for TB infection. If you have been vaccinated with BCG, the TST may be positive even if you do not have TB infection.
- The BCG vaccine is not effective against all strains of TB.