0
0
Barcelona, Spain – A groundbreaking study has revealed a potential link between gut microbiota, immunoglobulin A (IgA) deficiency, and the effectiveness of pneumococcal vaccines. Researchers at the Hospital del Mar Research Institute have discovered that an imbalance in gut bacteria, stemming from IgA deficiency, could explain why some individuals fail to mount a strong immune response to these crucial vaccines.
Published in the journal Science Advances, the study, led by the B Cell Biology Research Group, examined the effectiveness of two types of pneumococcal vaccines, one for children and one for adults, using genetically modified mouse models. These vaccines are designed to protect against Streptococcus pneumoniae, a bacterium that can cause severe illnesses like pneumonia.
The researchers focused on individuals with IgA deficiency, a condition where the immune system lacks the ability to produce sufficient IgA, an antibody crucial for regulating gut microbiota. Normally, IgA maintains a healthy balance of bacteria in the gut, preventing overgrowth and spread. However, in its absence, gut bacteria can proliferate, triggering a persistent immune response that ultimately leads to immune cell exhaustion.
“The vaccine may be less effective in the absence of immunoglobulin A because bacterial molecules originating from the gut overstimulate the immune system, leaving it exhausted,” explained Dr. Andrea Cerutti, a researcher at the Hospital del Mar Research Institute and ICREA. This exhaustion results in the overproduction of another antibody, immunoglobulin G (IgG), which, while present, does not effectively compensate for the lack of IgA in the context of the pneumococcal vaccine.
Mauricio Guzmán, a Ramón y Cajal researcher at the institute, added, “Under normal conditions, vaccines generate a response through pneumococcus-specific IgG antibodies. However, in patients with IgA deficiency, the lack of IgA reduces the vaccine’s effectiveness.”
The study also revealed that this abnormal IgG response and impaired vaccine response begin early in life, even though IgA deficiency primarily affects adults. This finding suggests that early intervention could be key.
“We should explore the possibility of early supplementation with recombinant IgA antibodies, as a form of immunotherapy, to counteract the excessive immune response to gut bacteria and prevent immune system exhaustion,” Dr. Cerutti proposed.
The research team believes these findings could pave the way for new preventative strategies for individuals at high risk of severe pneumococcal infections, such as those over 65 and individuals with weakened immune systems. Furthermore, the implications may extend to other vaccines as well.
Researchers from the Vall d’Hebron Research Institute (VHIR), the Sant Pau Biomedical Research Institute (IIB-Sant Pau), the Icahn School of Medicine at Mount Sinai, and Weill Cornell Medicine also contributed to this study.
Disclaimer: This news article is based on the provided research information and should not be taken as medical advice. The findings are preliminary, and further research is necessary to confirm these results and develop clinical applications. Individuals with concerns about vaccine efficacy or IgA deficiency should consult with a healthcare professional.
