What counts in cytometric analysis to document vaccine immunogenicity?

Abstract

Studies on vaccines and infectious diseases are increasingly adding immune cytometry (for e.g., flow cytometry or ELISPOT assays) to the routine use of antibody titers as a way to report immunogenicity. We advocate that the classical presentation of cytometric data in terms of percentages should best be supplemented by an absolute cell count per ml. We do this by discussing a simple hypothetical example illustrating that without knowledge of the absolute cell count per ml detection competition will render a correct comparison between different samples impossible in all situations where an inter-individual or intra-individual (longitudinal) variation in peripheral blood mononuclear cell concentrations is present.

Keywords: :

• ELISPOT
• antibody
• clinical trial
• flow cytometry
• immunogenicity
• immunology
• modeling
• vaccination

Disclosure of Potential Conflicts of Interest

B.O., V.V.T. and P.B. report no conflicts of interest. P.V.D. acts as (principal) investigator for vaccine trials PVD acts as (principal) investigator for vaccine trials conducted on behalf of the University of Antwerp, conducted on behalf of the University of Antwerp, for which the University obtains research grants from vaccine manufacturers. P.V.D. receives no personal remuneration for this work.

Acknowledgments

B.O. has received financial support from the Research Foundation Flanders (FWO).