Promising Tuberculosis Vaccine Breakthroughs
Tuberculosis is not just a disease of the past. Referred to as “consumption,” tuberculosis was the most feared illness in the world. TB was known as the “Great White Plague” at one time. Today in the U.S., this disease has generally remained under control, although it still kills many people worldwide.
There is still no known cure for tuberculosis, but researchers are working on developing a vaccine for people of all ages. Recently, scientists have gained strides in battling this disease, and there have been some significant breakthroughs in vaccine development.
Facts about Tuberculosis
Tuberculosis (TB) derives from the bacterium Mycobacterium tuberculosis. It usually invades the lungs but can infect the brain, kidneys, and spine.
Tuberculosis is an airborne illness. TB bacteria travel person-to-person through the air when infected individuals cough, sing, or speak near others. If you breathe in the bacteria, it settles in your lungs and can spread to other parts of your body. You cannot get tuberculosis through kissing, shaking hands, sharing food, or touching toilet seats and bedding.
Tuberculosis symptoms can vary, depending on where the TB bacteria reside. People with TB in the lungs typically suffer chest pain, a bad cough lasting longer than three weeks, and coughing up phlegm or blood. Other symptoms include:
- Chills
- Fatigue or weakness
- Fever
- Night sweats
- Poor appetite
- Unexplained weight loss
Many people have a latent infection, meaning they have TB bacteria but do not get sick. People with latent infection typically do not present symptoms of the disease. Although they cannot spread the infection to others, they may get sick if they do not get the proper treatment.
Tuberculosis was the leading cause of death in the U.S. at the turn of the 20th century. Today, it still poses a public health threat. In 2021, almost 8000 cases were reported in the U.S., with as many as 13 million living with latent infection. Besides COVID-19, tuberculosis is the deadliest infectious disease worldwide.
A New Tuberculosis Vaccine Breakthrough
Currently, there are no reliable tuberculosis vaccines for adults. The Bacille Calmette-Guérin (BCG) is often given to children in other countries where tuberculosis is more prevalent. Some healthcare workers take the BCG vaccine if they risk high exposure to TB bacteria.
Scientists are testing a new vaccine, which has shown promise in early clinical trials. Dr. Munyaradzi Musvosvi leads a research team at the University of Cape Town that has made strides in developing an mRNA vaccine that could be suitable for children and adults.
Although over 80% of South Africans are exposed to the TB bacterium, only about 10% develop tuberculosis. A question for researchers was whether the other 90% of South Africans have blood cells that boost their immunity to tuberculosis.
Blood samples collected since 2005 hold crucial information spurring the new vaccine-related development. More specifically, the blood drawn from about 6,000 high school students in South Africa has cells that contain information that Dr. Musvosvi’s team could only recently access thanks to new technology.
These cells provide insights into how the body’s immune system can attack and kill TB bacteria. Dr. Musvosvi’s team tried to test whether specific immune cells—T-cells—can identify proteins that TB bacteria make, which is crucial in fighting tuberculosis infection. Unfortunately, conducting this kind of analysis was too expensive until recently.
In 2019, Stanford University researcher Huang Huang developed an advanced and affordable technique that pinpoints what proteins a T-cell responds to. With access to this new technology, Dr. Musvosvi’s team was able to identify the T-cells that occur more often in people less likely to develop tuberculosis. Their research also led to discovering proteins that these T-cells target.
The development of messenger RNA (mRNA) vaccines brings the prospect of widespread tuberculosis immunization even closer. This type of vaccine contains the protein’s genetic code that the body needs to fight off a disease like tuberculosis. Several vaccine manufacturers are currently working on mRNA prototypes. Although it will take several more years before a vaccine is finalized and approved for distribution, scientists are closer than ever to a solution to tuberculosis infection.
Tuberculosis Prevention
If you have a latent TB infection, there is a chance you will never develop tuberculosis. However, there is an increased risk of developing the illness for some individuals:
- Infants and young children
- Older adults
- People with HIV infection
- Individuals with comprised immune systems
- People who inject illegal substances
- Individuals who were infected with the TB bacteria in the last two years
- People not receiving proper tuberculosis treatment in the past
People with latent infection should seek short-term treatment to prevent developing tuberculosis. The Centers for Disease Control and Prevention (CDC) and the National Tuberculosis Controllers Association (NTCA) recommend treatment regimens that last three to four months. Contact your physician if you have information on the drugs that treat a latent infection.
Use caution if you plan to travel to places with higher rates of tuberculosis, especially if you are HIV-positive or have other underlying medical conditions. Travelers visiting or working in hospitals and clinics tend to have a greater risk of exposure.
Research and materials for this article were compiled, written, and distributed on behalf of the National Public Health Information Coalition. The views and opinions expressed in this blog are those of the various authors and do not necessarily reflect the official policy or position of the National Public Health Information Coalition or its members.
References
https://www.cdc.gov/tb/topic/basics/default.htm
https://www.cdc.gov/tb/topic/basics/howtbspreads.htm
https://www.cdc.gov/tb/topic/basics/signsandsymptoms.htm
https://www.cdc.gov/tb/topic/basics/tbinfectiondisease.htm
https://www.lung.org/blog/how-we-conquered-consumption
https://www.cdc.gov/tb/statistics/default.htm
https://www.cdc.gov/tb/topic/basics/vaccines.htm
https://www.nature.com/articles/s41591-022-02110-9
https://medlineplus.gov/genetics/understanding/therapy/mrnavaccines/