Single Platform Solution for Identity and Quantification of Influenza Hemagglutinin (HA) mRNA Constructs and Resulting Expressed Proteins for Application to Influenza mRNA Vaccines

The rapid response to the Coronavirus Disease (COVID-19) pandemic highlighted mRNA as an attractive modality for vaccines and therapeutics to address infectious diseases, cancer, and other diseases. The current analytical methods for identification and quantification of both the mRNA construct as well as the resulting expressed protein(s) relevant to mRNA vaccines are inherently singleplex and usually labor and time intensive, presenting a bottleneck as these vaccines become increasing multivalent. Here, we first present performance data from an approximately 2-hour DNA microarray assay developed specifically to provide identity and quantity measurements for the mRNA constructs present in an influenza virus hemagglutinin (HA)-encoding multivalent mRNA vaccine regardless of the specific strain or codon optimization strategy utilized. The assay functions on both naked and lipid nanoparticle (LNP)-encapsulated mRNAs without the requirement of an upfront mRNA extraction or amplification. Second, we show that a separate [~]2-hour multiplexed immunoassay executed on the same VaxArray Platform can be utilized to measure the expressed proteins produced from these influenza HA mRNAs post-transfection as an in vitro potency assay readout. Both assays provide the necessary specificity for each component present in a multivalent mixture and represent new tools in the analytical toolbox for multiplexed mRNA vaccine analytics.