Social cohesion and loneliness are associated with the antibody response to COVID-19 vaccination

•Stress and other psychosocial factors are known to influence antibody response to vaccinations.•This study found that lower social cohesion was associated with a poorer antibody response to COVID-19 vaccination.•The association between social cohesion and lower antibody response was mediated by feelings of loneliness.•Those lower in social cohesion had higher levels of loneliness and this in turn was predictive of a poorer antibody response. Recent research has suggested that psychosocial factors influence the antibody response to vaccine, including SARS-CoV-2 (COVID-19) vaccines. Here we investigated whether social cohesion and loneliness were predictive of antibody response to a single dose of a COVID-19 vaccine. We also tested if the association between social cohesion and antibody response was mediated by feelings of loneliness. Participants (N = 676) COVID-19 antibody data were extracted from March 2021 wave of the Understanding Society COVID-19 study from the UK. Relevant socio-demographics, health and lifestyle, loneliness, social cohesion indices were also used in a series of hierarchical linear regression to test our main hypotheses. After controlling for covariates (e.g., age and chronic health conditions), lower social cohesion was associated with a lower antibody response. Further, the association between social cohesion and poorer antibody responses was mediated by loneliness; those reporting lower social cohesion also reported higher loneliness, which in turn was associated with lower antibody response. This study confirms that feelings of ‘being in it together’ relate to the strength of the antibody response to COVID-19 vaccination, emphasising the importance of the social cohesion agenda during the pandemic.