Time of day of vaccination does not relate to antibody response to thymus-independent vaccinations

Variable responses to vaccination are of historical and current concern, particularly among vulnerable groups. Biochemical and behavioural methods of improving vaccination response have been examined. There is some evidence that vaccinating in the morning could enhance vaccine responses, however, this has consistently been shown in thymus-dependent vaccinations, such as influenza. The present analysis of data from two observational studies of the association between psychosocial factors and vaccination response. These data included response to a thymus-independent vaccination - pneumococcal polysaccharide vaccine, examined morning versus afternoon vaccine administration in 75 healthy young adults and 61 parents, including 32 caregivers of a child with a development disability and 29 control parents. In both datasets, timing of vaccination was not related to antibody response. This suggests that effects of time of day may be limited to thymus-dependent vaccinations although replication in a large randomised controlled trial using other thymus-dependent vaccinations is required.