Mind matters: the surprising link between mood and vaccine response
A good mood may be associated with improved immune responses to mRNA vaccines, research suggests.
- 17 June 2025
- 3 min read
- by Linda Geddes
A sunny disposition could do more than lift your spirits – it could also boost your immune response to vaccines.
Scientists have discovered that people who were in a more positive frame of mind when they received a COVID-19 vaccine produced more protective antibodies in response to it.
The research adds to growing evidence of a link between the mind and immune system and could eventually lead to interventions that could bolster people’s response to vaccination.
Mind-body connection
Previous research has suggested that factors such as stress, depression or poor sleep can suppress the immune system, potentially reducing the body’s response to vaccines.
For instance, when researchers led by Anette Pendersen at Aarhus University in Denmark combined the results of 13 studies, they found that psychological stress was consistently linked to weaker antibody responses to the flu vaccine.
More recently, several studies have suggested that positive emotions may boost people’s immune response to vaccines.
Prof Kavita Vedhara at Cardiff University in Wales, UK, and colleagues wondered if these findings might also apply to mRNA-based vaccines, such as those to protect people against COVID-19.
“Research with traditional vaccines, such as flu, has shown that some psychological factors, such as stress, are associated with vaccines working less well, particularly in older adults. However, mRNA vaccines work differently. Rather than using a weakened version of a virus, mRNA vaccines teach our cells how to make a protein that triggers an immune response to the virus,” Vedhara said.
“During the pandemic there was some evidence to suggest that these mRNA vaccines offered greater protection than more traditional vaccines. We were interested to know whether, despite their superiority, could psychological factors still influence how well these vaccines worked?”
To investigate, they collected blood samples from 184 UK adults before they received their first dose of Pfizer/BioNTech's BNT162b2 COVID-19 vaccine, and again four weeks after receiving their second dose. These participants were also asked to complete questionnaires measuring stress, anxiety, depression and positive mood.
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Positive boost
The research, published in Brain, Behaviour and Immunity, found that people who reported fewer depressive symptoms and greater positive mood at the time of their first vaccination went on to have significantly larger antibody responses after their second dose.
However, there was no evidence to support anxiety or stress impacting people’s vaccine responses.
“Our research provides some of the best evidence to date that psychological factors are associated with mRNA vaccine responses,” Vedhara said. “Although these effects are modest, they are striking because we are seeing these relationships in vaccines that are otherwise very effective and, in particular, in younger adults – who usually respond well to vaccines.
“These findings support a need to understand how these effects are occurring and how we might develop new treatments to optimise people’s mood at the time of their vaccines to ensure they work as well as possible.”
