Development and validation of a commercial dsRNA (J2 based) ELISA for the quantification of double-stranded RNA in biological preparations

mRNA vaccines have quickly gained ground after both BioNTech and Pfizer gained Emergency Use Approvals for their mRNA based SARS-CoV-2 vaccines. The development of a successful mRNA vaccine requires both stability and purity. After in vitro transcription, purification processes must be performed for removal of DNA template as well as contaminants like the highly immune stimulatory double-stranded RNA (dsRNA), which can induce fatal immune responses. dsRNA is typically removed using HPLC methods, though ELISA is used to measure the presence and therefore additional purification requirements for a successful vaccine. Currently, only one ELISA for estimation of dsRNA is commercially available - a qualitative assay in a reagents-box format, that requires the scientist to coat, optimize and validate their own assay for estimation of dsRNA. This allows for human error and variability in detection. Additionally, since the ELISA available are qualitative, the scientist is required to potentially run the same sample through purification multiple times until a satisfactorily purified sample is received with guess estimates and no benchmarks on impurity levels. The objective was to develop a new, sensitive, easy to use and pre-validated sandwich assay for measurement of dsRNA, using J2 antibodies, the gold standard in the industry for detection of dsRNA contaminants. This would ensure standardization of results, and a quantitative result would allow scientists to have a better understanding of the purity of their sample, and therefore the efficiency of their purification method