Assay Harmonization and Use of Biological Standards To Improve the Reproducibility of the Hemagglutination Inhibition Assay: a FLUCOP Collaborative Study

Abstract

The hemagglutination inhibition (HAI) assay is the most commonly used serology assay to detect antibodies from influenza vaccination or influenza virus infection. This assay has been used for decades but requires improved standardization of procedures to provide meaningful data.

An external quality assessment feasibility study; cross laboratory comparison of haemagglutination inhibition assay and microneutralization assay performance for seasonal influenza serology testing: A FLUCOP study

“…The goal of the FLUCOP project is to have a direct and evidencebased impact on the quality of regulatory decisions and to provide valid and appropriate serological tools for the future definition of alternative correlates of protection for (novel) influenza vaccines. The consortium has made considerable progress with standardization of the HAI assay and Enzyme-Linked-Lectin Assay (ELLA) with large collaborative studies carried out and freely available published SOPs (2,3). Additionally collaborative studies to standardize the Microneutralization (MN) assay have also been carried out (manuscript in preparation).…”

Interlaboratory Reproducibility of Standardized Hemagglutination Inhibition Assays

“…The FLUCOP collaborative (Waldock et al) recently reported similar reductions in interlaboratory variation through the use of a consensus protocol and common critical reagents ( 10 ). This group also demonstrated that the use of a pooled postvaccinated human serum pool as a reference standard provided similar reductions in interlaboratory variation when different protocols and reagents are used.…”

“…Interestingly, Waldock et al demonstrated no cumulative reduction in interlaboratory variation when using a consensus protocol, common critical reagents, and a reference standard ( 10 ). They suggest that the improvements in assay performance obtained either through the use of a consensus protocol and common reagents or the use of a reference standard, are close to the limits of improvement possible.…”

Robustness of the Ferret Model for Influenza Risk Assessment Studies: a Cross-Laboratory Exercise

“…However, as this model becomes more commonly employed in laboratories worldwide, there is a pressing need to capture the level of variability and heterogeneity intrinsic to this research. Cross-laboratory exercises have been employed in the past to evaluate the reproducibility of assays employed for influenza virus public health efforts (3)(4)(5)(6)44), but no such exercise has been performed to date evaluating influenza virus transmissibility in the ferret. In this exercise, 11 laboratories independently evaluated the ferret-to-ferret transmissibility of Cal/09 and ruddy turnstone/09 viruses that possess distinct transmission potential in humans.…”

“…These characterization efforts are undertaken by laboratories worldwide, employing zoonotic virus strains and experimental protocols that are similar but not uniform, which may lead to variation in the experimental results. To date, limited assessments of interlaboratory variability have been conducted for influenza virus serological assays (3)(4)(5)(6), but not for other in vitro or in vivo assays.…”