At the same time, there are also opportunities to improve the response to vaccines. For example, by vaccinating at a more suitable time. Follow-up research must show what time that should be. The discovery may also contribute to the development of new tuberculosis vaccines and new vaccines in general.
Tuberculosis is an infectious disease caused by a bacterium. The disease can occur (and cause damage) in any organ, but it is often found in the lungs. Common symptoms include persistent coughing (sometimes coughing up blood), weight loss and night sweats. A month-long course of medication is available against tuberculosis, but if a person does not receive proper treatment, the disease can be fatal. According to the WHO, more than 1.3 million people in the world will die from tuberculosis in 2022.
The BCG vaccine has also been available against tuberculosis for more than a century, which reduces the chance that tuberculosis will make someone seriously ill. The vaccine contains weakened tuberculosis bacteria. These are harmless, but they must ensure that the immune system comes into action. It was already known that the vaccine mainly protects young children, but not so much in adults, who often transmit the disease.
A quarter of research participants are able to clear bacteria without a vaccine
During the study, research participants, all of whom had never had tuberculosis, received the BCG vaccine. Researchers in the laboratory used blood tests to see whether cells of the immune system were able to inhibit bacterial growth. For example, Krista van Meijgaarden (PhD candidate at the Department of Infectious Diseases) and Simone Joosten (Associate Professor of Infectious Diseases) discovered that the vaccine did not lead to the immune system response needed to actually clear the infection in everyone.
About a quarter of people were already able to kill the bacteria before vaccination. For another quarter of the participants, this happened after vaccination. So about half were unable to clear the bacteria, regardless of BCG vaccination. Moreover, the two groups that can clear bacteria appeared to do so in different ways. That was also a new discovery.
Response to vaccination may soon be predictable in advance
The researchers do not know why the response to the vaccine may differ. Finding that out is the holy grail. However, they do have strong indications that it has something to do with the metabolism and status of people’s immune system at the time of vaccination. It is possible that the response to vaccination can be predicted in advance by examining properties of the immune system. “Suppose – and this is just an example – it has something to do with vitamin C,” says Joosten. “Then you may be able to increase vaccine effectiveness by having people take vitamin C. We can use this to bring about enormous changes worldwide,” she says.
Important for testing new vaccines
The LUMC researchers therefore speak of a breakthrough. “Before this, we did not even know that there were differences in the immune response. We have now solved a piece of that puzzle,” says Van Meijgaarden. The new results could lead to better and more effective use of the BCG vaccine. The findings also contribute to the development of new tuberculosis vaccines. Moreover, it would the study published in Nature Communications could also be an inspiration for other vaccine studies.
2024-01-08 16:15:47
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