Can Your Thoughts Boost Your Vaccine Response?
A Summary of Brain Training and Hepatitis B Vaccination Study
Article: Lubianiker et al. (2026). "Upregulation of reward mesolimbic activity and immune response to vaccination: a randomized controlled trial." Nature Medicine
DOI: https://doi.org/10.1038/s41591-025-04140-5
Executive Summary (The Elevator Pitch)
Scientists trained people to increase activity in their brain's reward center using real-time MRI feedback, then gave everyone a hepatitis B vaccine to see if "thinking positively" could boost immune response. People who learned to sustain higher activity in a specific brain region (the VTA) using mental strategies involving positive expectations developed stronger antibody responses to the vaccine. While the differences between groups weren't statistically significant, the findings suggest that consciously generated positive thoughts might influence how well your immune system responds to vaccination—providing a potential scientific basis for why optimism during medical treatment (the "placebo effect") might actually help your body heal.
Who Did This Research?
Lead Authors:
- Nitzan Lubianiker (Yale, Princeton, Tel Aviv)
- Tamar Koren (Tel Aviv)
- Asya Rolls (Tel Aviv/Technion) - corresponding author
- Talma Hendler (Tel Aviv) - corresponding author
Institutions:
- Tel Aviv University and Tel Aviv Sourasky Medical Center (Israel)
- Yale University and Princeton University (USA)
- Technion Israel Institute of Technology
Conflicts of Interest:
- Dr. Hendler is Chief Medical Scientist at GrayMatters Health (a neurofeedback company)
- Four authors (Hendler, Rolls, Lubianiker, Koren) have filed a patent on using neurofeedback to boost immune responses
- Funding came from Joy Ventures foundation and Israeli government innovation grants
What They Found
The study measured whether training people to voluntarily increase activity in their brain's reward system could enhance their immune response to vaccination:
- 85 healthy adults participated (average age 25, 60% female)
- Participants were randomly assigned to train different brain regions using fMRI neurofeedback over 3-4 sessions
- Immediately after the last training session, everyone received a hepatitis B vaccine
- Blood tests measured antibody levels before vaccination and at 2 weeks and 4 weeks after
Key Result: People who achieved greater increases in VTA (ventral tegmental area) activity during training showed larger antibody responses to the vaccine (r=0.31, statistically significant). However, the experimental group didn't show significantly higher antibody levels overall compared to control groups.
Interesting Finding: When researchers analyzed what people were thinking during successful brain training, they found that "positive expectations"—consciously imagining or anticipating positive outcomes—was uniquely linked to sustained VTA activation.
Strengths (What They Did Well)
Rigorous Scientific Design
- This was a preregistered, double-blind randomized controlled trial—the gold standard for medical research. Neither participants nor experimenters knew who was in which group until after all data was analyzed.
Novel Control Condition
- Instead of comparing brain training to nothing, they had a control group that also did brain training but on different brain regions. This helps ensure any effects are specific to the reward system, not just general practice effects.
Thorough Alternative Explanation Testing
- The researchers systematically ruled out multiple alternative explanations: general task success, reward responsiveness during feedback, baseline motivational traits, and functional brain connectivity patterns. This strengthens confidence in their specific VTA-immune link.
Translation from Animal Research
- Previous mouse studies showed similar brain-immune connections, and this study successfully demonstrated the same phenomenon in humans, which is scientifically important for validating animal research.
Innovative Mental Strategy Documentation
- They developed a systematic method to characterize what people were actually thinking during neurofeedback training (45 different mental features), rather than just assuming or guessing.
Multiple Statistical Safeguards
- They included proper correction for multiple comparisons, assessed both early and sustained brain activity patterns, and used mixed-effects models to account for individual variability.
Weaknesses (Where Questions Remain)
Main Hypothesis Not Supported
- The primary prediction—that the experimental group would show higher antibody levels than control groups—was not confirmed. The significant finding was a correlation within individuals, not a group difference, which is a weaker type of evidence.
Control Group Also Activated Reward System
- Both the experimental group and the control group increased VTA activity during training, making it unclear why one group was called "experimental" when both seemed to be doing similar things neurologically.
Modest Effect Size
- The correlation between VTA activity and antibody response (r=0.31) is statistically significant but accounts for only about 10% of the variation in immune response, suggesting other factors are more important.
Post-Hoc Data Exclusions
- Seven "non-responders" to the vaccine were excluded from analysis, but this exclusion criterion wasn't specified in the original pre-registration, which raises questions about cherry-picking favorable data.
Small Sample for Clinical Significance
- With only 30 people per group in the final analysis (after exclusions), this study was designed more to test mechanisms than to prove clinical effectiveness. Larger trials would be needed to recommend this as a treatment.
Self-Report Limitations
- The characterization of mental strategies relied entirely on what people reported thinking after the sessions, which may not accurately capture what was actually happening in their minds during training.
Unclear Mechanism
- The study shows an association between brain activity and immune response but doesn't prove causation or explain exactly how the brain is communicating with the immune system (through hormones? nerves? other pathways?).
Limited Generalizability
- Only one vaccine (hepatitis B) was tested in young, healthy adults. Would this work for flu shots? In elderly people? For actual infections rather than vaccines? We don't know.
Timing Questions Unanswered
- The vaccine was given immediately after brain training. Would the effect persist if people were vaccinated days or weeks later? The study doesn't address how long any brain-immune effects might last.
Bottom Line
This study provides intriguing preliminary evidence that training your brain's reward system through positive expectations might modestly enhance vaccine responses, though the practical significance remains uncertain. Think of it as early-stage research that opens doors for future investigation rather than something that should change medical practice today.