![[FILE] Women take part in a march on the occasion of World Tuberculosis Day, in Chennai, (India), Tuesday, March 23, 2010. EFE/Nathan G.](https://i0.wp.com/efe.noticiasdopara.net/wp-content/s/2025/01/rss-efede39722998338c9ed4380885946078f70aac9508w.jpg?fit=1920%2C985&ssl=1)
Science Desk, Jan 10 (EFE).- Scientists have developed a breakthrough mechanism that makes the intravenous Bacillus Calmette-Guérin (BCG) tuberculosis vaccine safer and more effective by enabling the injected viral load to self-destruct after completing its task, thereby reducing the risk of accidental self-infection.
Researchers from the American universities of Pittsburgh and Cornell have developed the innovative method of enhancing the efficacy and safety of the BCG tuberculosis vaccine.
The World Health Organization has labeled tuberculosis the deadliest disease of 2024, with more than 10 million new infections and 1.3 million deaths annually.
The BCG vaccine, widely used in countries with high tuberculosis prevalence, primarily protects children against severe forms of the disease, such as tuberculous meningitis and miliary tuberculosis.
However, the traditional intradermal injection provides limited protection for young children and almost none for adults.
In an article published in Nature Microbiology, researchers detailed a new intravenous vaccination approach that significantly improves the vaccine’s effectiveness and safety. The method has shown promising results in tests on macaque monkeys.
An Autodestructive Vaccine In earlier studies, the scientists observed a 100,000-fold reduction in bacterial load in the lungs of animals vaccinated intravenously compared to those given the standard intradermal injection.
Additionally, nine out of 10 animals that received the intravenous BCG vaccine showed no signs of lung inflammation.
To address safety concerns associated with intravenous vaccine istration, the researchers designed a double safety switch. The BCG particles are programmed to self-destruct after exposure to the antibiotic doxycycline or when doxycycline treatment is stopped. This mechanism ensures that any remaining mycobacteria cannot cause infection.
This double safety switch protects animals from tuberculosis with the same efficacy as standard BCG vaccination but allows for faster and safer elimination of the vaccine, even in immunocompromised individuals, the authors said in the study.
Stronger Immune Response In macaque monkeys, the self-destructing BCG vaccine elicited a more robust immune response and offered better protection against tuberculosis than the traditional intravenous BCG vaccine.
None of the monkeys that received the updated vaccine displayed detectable lung inflammation eight weeks after being infected with tuberculosis.
Moreover, six out of eight monkeys had no recoverable traces of live tuberculosis, compared to only two out of eight in the standard BCG group.
Despite the challenges that lie ahead in conducting clinical trials to extend the use of the updated vaccine in humans, researchers remain hopeful.
“We hope that this ‘kill switch’ BCG strain could limit safety concerns over intravenous vaccine istration and provide an option for a safer and more effective vaccination route for individuals who are immunocompromised,” said Joanne Flynn, a professor of microbiology and molecular genetics at the University of Pittsburgh.
The discovery marks a significant step forward in the global fight against tuberculosis, offering new hope for better prevention methods in vulnerable populations. EFE
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