Positive thinking could boost immune response to vaccines, say scientists [View all]

[highplainsdem]

Source: Guardian

In the study, healthy volunteers took part in brain training sessions in which they tried different mental strategies to boost activity in particular parts of the brain. They knew how well they were doing thanks to real-time feedback in the form of scores that rose in line with brain activity.

After four training sessions, the volunteers were given a hepatitis B vaccine. They then gave blood two and four weeks later, which researchers analysed for antibodies against hepatitis.

The scientists found that people who boosted activity in part of the brain’s reward system called the ventral tegmental area (VTA) had the strongest immune response to the vaccine. And those who boosted it most successfully did so through positive expectations, or imagining good things happening.

The effect may prove useful in boosting patients’ immune systems, but large trials are needed to show if there is any clear medical benefit. Dr Tamar Koren, a co-author, said the team is now investigating whether other parts of the immune system are also affected, such as inflammation.

Read more: https://www.theguardian.com/society/2026/jan/19/positive-thinking-could-boost-immune-response-to-vaccines-study-finds

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From the study, published in Nature today:

https://www.nature.com/articles/s41591-025-04140-5

Growing evidence points to a close neurophysiological link between brain and body. Recent rodent studies have shown that the dopaminergic mesolimbic pathway, which underlies expectations of positive outcomes, also modulates immune function. However, it remains unknown whether a similar brain-immune link exists in humans and whether it involves conscious positive expectations. In a preregistered, double-blind randomized controlled trial, we used fMRI neurofeedback (NF) to train healthy participants to increase reward mesolimbic activity through self-chosen mental strategies, followed by an immune challenge with the hepatitis B virus (HBV) vaccine and assessments of HBV antibody (HBVab) levels. Eighty-five participants were randomized to (1) reward mesolimbic upregulation (n = 34), (2) non-mesolimbic control upregulation (n = 34) or (3) no-NF control (n = 17). Prespecified primary outcomes were (1) differences in reward mesolimbic activation between NF groups, (2) correlation between reward mesolimbic upregulation and post-vaccination HBVab changes across both NF groups and (3) group differences in post-vaccination HBVab changes. Both NF groups showed significant increases in reward mesolimbic activation. Notably, greater ventral tegmental area (VTA) upregulation—but not nucleus accumbens or control region activation—was associated with larger post-vaccination increases in HBVab levels (r = 0.31, P = 0.018). Sustained VTA upregulation was further linked to mental strategies involving positive expectations. Post-vaccination antibody levels did not differ between groups, and no adverse effects occurred. Together, these findings suggest that consciously generated positive expectations can engage reward circuitry to influence immune function, a process that may be leveraged for non-invasive immune modulation.