Impact of IDP on Enhancing Immune Response to the Influenza Vaccine: A Double-Blind, Randomized, Placebo Controlled, Pilot Study

Abstract

Background: Immune Defense Proteins (IDP) is a complex of milk proteins that has been shown to have anti-inflammatory activity and provide protection from infection. The effect of IDP on enhancing immune response after an influenza vaccine in humans has not been shown and is the objective of this study. Methods: An 8-week, double-blinded, randomized, placebo-controlled pilot study was conducted. Fifty three participants were randomized to three study arms, consuming either high dose IDP (200 mg), standard dose IDP (50 mg) or placebo. Serum samples were collected prior to influenza vaccination (at 4 weeks) and 2 and 4 weeks postvaccination. Levels of influenza-specific Ig were measured in serum using enzyme linked immunosorbent assay (ELISA). Proportion of individuals achieving a 4-fold or greater increase in antibody levels, the geometric mean antibody levels after influenza vaccination and effect size of IDP dosage were determined. Results: Statistically significant difference was observed in geometric mean influenza-specific antibody levels between high dose IDP and placebo arms at 4 weeks postvaccination. High dose IDP participants exhibited a sustained 4-fold increase in antibody levels 4 weeks postvaccination. The high dose IDP provides a medium effect size trending towards large effect size at 2 and 4 weeks postvaccination compared to participants that consumed the placebo.