A TruCulture Whole Blood Assay to Evaluate Annual Flu Vaccine Recall Responses

Abstract

Evaluation of vaccine efficacy to protect against future infection remains a challenge. One of the difficulties lies in developing an antigen specific recall assay that can be applied across clinical sites. TruCulture is a whole blood collection and culture system that was designed for ex vivo/in vitro evaluation of immune responses for clinical trials. This abstract demonstrates a TruCulture tube that is highly effective in eliciting recall responses against Influenza A hemagglutinin (HA) proteins after the annual flu vaccine. Whole blood from 10 healthy donors were collected at 2 days pre- and 14 days post-vaccination (Afluria, Sequiris). Blood was collected in TruCulture tubes containing 5mg recombinant HA antigens (Immune Technology Corporation). After incubation at 37°C for 48 hours, the supernatants were collected and analyzed for 13 analytes by OptiMAP and 47 analytes by TruCulture MAP (Myriad RBM). Several analytes (such as IFNγ, IL-1β, IL-3, IL-4, IL-6, IL-10, IL-12, IL-17, and IL-23) demonstrated an increase at 14 days after the flu vaccination compared to samples taken prior to vaccination. This increase is specific to the recombinant HA antigens from flu strains included in the flu vaccine administered. The increase in these analytes were either not observed or at significantly reduced levels when the recall response was conducted using recombinant HA antigens from flu strains not included in the vaccine administered. TruCulture preloaded with HA antigens can be a valuable tool to evaluate human immune responses to the annual flu vaccine and indicates that a similar strategy using antigen-specific TruCulture tubes can be developed for the evaluation of any novel vaccine.