When I was growing up in Mexico, an epidemic of tuberculosis struck my town. In an effort to protect us, the school staff rounded us up at lunch time and took us into a classroom to immunize us with the Bacillus Calmette-Guérin (BCG) vaccine. That vaccine is not very effective at preventing tuberculosis pneumonia, but it does show some effectiveness against tuberculosis meningitis in children. According to my parents, that is what the school wanted to prevent. For any pneumonia cases, they were ready to deploy antibiotics.
I still have the scar from the vaccine on my arm, and it reminds me of where I came from. You see, the BCG vaccine is not given in the United States. The work of George W. Comstock, MD, showed that screening and antibiotic treatment was preferred over relying only on the vaccine and waiting for cases to show up. Unfortunately, many developing countries lack the capacity to screen all of their population effectively and/or deliver antibiotics on a mass scale.
That was the case in Mexico in the 1980s. If we had been just a few kilometers north, the sick people would have been given antibiotics and ordered to stay home or hospitalized. The children would then be screened for latent tuberculosis infection and given antibiotics if they tested positive, even if they were not showing any symptoms.
This week, researchers working on a new tuberculosis vaccine found that it was showing good effectiveness at preventing diseases and — what was truly remarkable —
it cleared up latent infection as well prevented latent infection from becoming active. If these results are found to be accurate and reproducible, it would mean a decreased need for antibiotic treatment in poor parts of the world. All those places would need is a way to deliver the vaccine, and they already deliver vaccines like BCG.
According to the World Health Organization, tuberculosis is the number one cause of death from an infectious disease in the world, killing an estimated 1.5 million people a year, many of them co-infected with Human Immunodeficiency Virus (HIV). Not only that, but the use of antibiotics is giving rise to antibiotic-resistant strains. Some strains are resistant to all known drugs, leaving people infected few options — if any — for recovery.
Now, some fun… If you’re a fan of video games — and even if you’re not — this quick 15-minute video talks about tuberculosis and how it shaped the narrative of one of the most successful games of the last few years. (Pay close attention to the counter at the top left of the video and what it means.) There’s also a good explanation of how tuberculosis causes disease.
UPDATE (11/4/19): We clarified the statement about clearing up latent infection. The vaccine shows signs of preventing latent infection not clearing it. We regret the error.