Tuberculosis is a disease caused by the bacteria Mycobacterium tuberculosis that kills millions of people every year. BCG, or bacille Calmette-Guerin, is a vaccine prepared from a live attenuated strain of Mycobacterium bovis that is the only approved vaccine against TB but has proven to not be effective against pulmonary TB. BCG is a vaccine given in the muscles of the upper arm which provides protection against tuberculosis meningitis and miliary TB but not against TB that enters the lungs, which is the most common portal of entry. BCG is used in countries with a high prevalence of TB but is not used in the United States because there is a low risk for infection, this vaccine is not effective against pulmonary TB, and this vaccine causes tuberculin skin tests to read positive which makes it difficult to identify patients with actual TB. To combat pulmonary TB, researchers led by Dr. Jordi Torrelles have developed a new type of TB vaccine that has so far proven to be effective against pulmonary TB in animals and human macrophages.
Intranasal Delipidated BCG Vaccine
One of the main reasons tuberculosis is so damaging to the lung is from the potent pro-inflammatory lipids contained in the cell wall of the Mycobacteria. These lipids induce rapid and powerful innate immune responses that cause inflammation and damage to the lung tissue. Researchers discovered that removing these lipids from the BCG vaccine (delipidation) leads to lowered innate inflammatory responses without affecting the viability of the vaccine. This led researchers to hypothesize that delipidated BCG (dBCG) can provide efficient protection for pulmonary TB. This vaccine is so groundbreaking because it could provide immunity for people of any age or stage of immunocompetency. BCG currently cannot be given to immunocompromised patients such as elderly or HIV/AIDS who are at a high risk for developing TB. This modified dBCG vaccine causes less burden and delays immunopathology so immunocompromised individuals can tolerate this type of vaccine. Dr. Torrelles claims that this type of vaccine does not fall into the general category of vaccines like attenuated or inactivated so he has classified dBCG under a new category of vaccines called “selective attenuation.”
I personally find this research so interesting because if it goes through all necessary testing and becomes approved by the FDA, the majority of the population, including those that are immunocompromised, can have effective protection against the most common form of TB that kills so many people. I also find it creative that the researchers predict this vaccine to be an intranasal spray that works similar to an asthma inhaler (but like through the nose). If you’re like me, shots are not my thing, especially when I was a child so having a vaccine that can just take a spray or so up the nose would provide a lot more comfort for those afraid of needles. I truly hope that this vaccine is successful and that millions of lives across the world can be saved.
Vaccine Culture 