Researchers at the Murdoch Children’s Research Institute have shown that the BCG tuberculosis vaccine has an immune-boosting effect that lasts more than 14 months after the vaccine is administered. Article published in the journal Science Advances.
The randomized controlled study included 130 infants from the Melbourne study. One group received the BCG vaccine within 10 days of birth. 14 months after the vaccine, the scientists found that the activity of the genes in the monocytes of the vaccinated children was very different from the control group.
Monocytes are a subtype of immune cells that become resident macrophages after maturation, that is, specialized and localized to a particular tissue or organ. The off-target effects of the BCG vaccine were first identified in Africa, where a significant reduction in mortality in vaccinated children was observed. According to the concept of trained immunity, the BCG vaccine increases the ability of the immune system to fight any infection, not just tuberculosis, precisely due to the reprogramming of monocyte genes.
Previously, immunostimulation after BCG vaccination was studied only in adults and only 1-3 months after vaccination. Results in adults do not always apply to children most likely to receive the vaccine. The authors of the study show for the first time how the BCG vaccine can have a long-term effect on the immune system of infants, and they also get further proof of the validity of the concept of trained immunity.
The next step for researchers will be to explore what effects this early trained immunity has on the body in the future, including adulthood.
The research team collaborated with scientists from Radboud University in the Netherlands, the International Educated Immune Consortium (INTRIM), the University of Melbourne, the Walter and Eliza Hall Institute of Medical Research, and the University of Bonn in Germany.