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New findings reveal that obesity significantly impaired the quality and longevity of antibody responses to a Pseudomonas aeruginosa vaccine in a mouse model. The impaired antibody production was due to defects in germinal centers, a transient part of the immune system where specialized immune cells, called B cells, produce antibodies and build memory against pathogens
Researchers say the findings, which are published in The Journal of Immunology , provide an important reason for why traditional vaccines, which rely on high antibody production, tend to underperform in people with obesity.
“We hope these findings shift the focus of vaccine design and lead to more effective, tailored vaccines for the millions of people living with obesity who are at higher risk for severe respiratory infections,” said Wendy L. Picking , PhD, Professor in the Department of Pathobiology and Integrative Biomedical Sciences at the University of Missouri and lead author of the study.
Though the antibody response was decreased, the vaccine did generate a strong response from lung tissue-resident memory T cells. These specialized cells live permanently in the lungs and do not circulate through the bloodstream. In response to the P. aeruginosa vaccine, resident memory T cells provided early, critical protection against infection that was not observed in mice fed a normal or low-fat diet. This suggests that the tissue-resident memory T cells could be compensating for antibody deficiencies.
“Instead of just trying to boost blood antibody levels, we should intentionally design vaccines that prioritize tissue-resident immunity, ensuring protection directly where pathogens like Pseudomonas enter the body,” shared Dr. Picking.
P. aeruginosa is a leading cause of severe pneumonia for people with obesity and emerging antibiotic resistance increasingly makes the infection difficult to treat, highlighting the need for effective vaccines. To date, no other studies have examined the effectiveness of vaccines targeting gram-negative bacterial pathogens, like P. aeruginosa , in people with obesity. Understanding the relationship between obesity and the immune system addresses a significant gap in current vaccine research.
The researchers plan to build on these findings by identifying the specific molecular signals that enable the lung tissue-resident memory T cells to become activated despite the chronic inflammation associated with obesity. This could allow researchers to optimize vaccine formulations to further boost these resident memory cells. Ultimately, the researchers seek to create a vaccine that ensures robust protection for all individuals, regardless of their metabolic health.
The research article will be available in The Journal of Immunology or you can read more on AAI News & Views on April 13, 2026. Once published, the research article will be available at: doi.org/10.1093/jimmun/vkag052 .
Requests for interviews with authors, The Journal of Immunology , or the American Association of Immunologists can be made to kpalmer@aai.org .
About The American Association of Immunologists
The American Association of Immunologists (AAI) is one of the world’s largest organizations of immunologists and scientists in related disciplines. Our mission is to improve global health and well-being by advancing immunology and elevating public understanding of the immune system. AAI members are responsible for some of the most significant biomedical discoveries of the past century, including the development of life-saving cancer immunotherapies, antibody therapies, transplant technologies, and vaccines. We support scientists across the field of immunology through knowledge dissemination, community building, advocacy, and public outreach.
About The Journal of Immunology
The Journal of Immunology ( The JI ) publishes peer-reviewed manuscripts describing novel findings in all areas of experimental immunology, including both basic and clinical studies. The JI is owned by the American Association of Immunologists and published in partnership with Oxford University Press.
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Animals
For Review Only Effectiveness and Immunogenicity of a Nanoemulsion Protein Subunit Vaccine Against Pseudomonas aeruginosa: Investigation in Diet-Induced Obese Mice
13-Apr-2026