Chronovaccination: The competitive edge in vaccine effectiveness?

Although chronovaccination - controlling the time of day of vaccination (TODV) to enhance protective immunity - has been described as a potential paradigm shift in vaccine immunology, unequivocal evidence for clinical benefit outweighing other societal and practical considerations has yet to be established. The current mixed evidence for chronovaccination providing an additional competitive edge to vaccine effectiveness is likely due to complex population-level interactions between various circadian, environmental, and sociodemographic factors influencing antibody responses to vaccines. Nonetheless, TODV shows the greatest potential for sub-cohorts of populations, particularly older age, and immunocompromised groups. In these contexts, this review provides a Person, Place, and Time consideration of the factors influencing the outcomes of chronovaccination studies.