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The bacilli Calmette-Guerin (BCG) vaccine, used in many countries, helps to prevent the spread of tuberculosis (TB). TB is one of the most prevalent infectious diseases globally. According to the United States Agency for International Development (USAID), this bacterial infection kills 4,300 people every day, mostly in underdeveloped countries.
This is why many foreign-born individuals get the BCG vaccine at some point in their lives. However, in the United States, BCG is not recommended in the list of vaccinations. This article will explain more about the vaccine and why it is not prescribed in the U.S.
What Is the BCG Vaccine?
The BCG vaccine consists of a weakened strain of Mycobacterium bovis, which is closely related to M. tuberculosis, the organism that causes tuberculosis. Developed by bacteriologists Albert Calmette and Camille Guerin in 1921, it produces an immune response that helps protect people against infection with tuberculosis.
This vaccine is commonly given to young children in countries where tuberculosis is rampant. That does not include the United States, which does not have many cases of TB annually. The vaccine is mandatory in many European countries, including:
- Hungary
- Bosnia
- Bulgaria
- Croatia
- Estonia
- Turkey
- Ukraine
There is also a universal vaccine policy in Central and South American countries. Brazil requires it for healthcare personnel, and indigenous communities in Canada receive it. Certain Asian countries also give it to babies at birth.
How Effective is the BCG Vaccine?
The effectiveness or efficacy of the BCG vaccine depends on many different factors. One 1994 study reports it is 50% effective in preventing widespread infection.
According to the World Health Organization (WHO), the vaccine is effective against meningitis and TB in children. However, it does not prevent the primary infection. In other words, someone with the vaccine can still get TB, but it helps fight it, so it is not as severe. However, a latent infection can come back at some point in the person’s life. The vaccine does not protect against that reactivation.
TB Epidemiology in the U.S.
The Centers for Disease Control and Prevention reports there were a little over 8,000 cases of TB in the U.S. in 2022. That is a 5.9% increase since 2021.
However, the number of cases of TB declined significantly in 2021. In that year, there were 609 deaths attributed to the infection.
Why Isn’t the BCG Vaccine Given in the U.S.?
The primary reason the vaccine is not common in the United States is the low infection rate. It is also not generally effective on adults with TB.
Many industries, especially healthcare, require tuberculin skin tests as part of tuberculosis prevention in the U.S. The BCG vaccine will cause a positive reaction, making the testing less effective. It is easier to test for TB and then isolate and treat those who are positive than try to figure out who might have it in a vaccinated population.
Today, the goal is early identification and treatment of active and latent TB. Other industries that test employees for TB include:
- Zoos
- Child care centers
- Laboratories
- Corrections
- Homeless shelters
The U.S. public health strategies involve screening those most vulnerable and allowing for treatment before the infection can spread in communities.
