mRNA vaccines have become a cornerstone of modern immunization strategies, but potency testing remains a critical challenge. Existing methods often require complex equipment, specialized training, and significant time, making them difficult to implement consistently across global manufacturing sites—particularly in low- and middle-income countries (LMICs). Without standardized, accessible potency assays, manufacturers face delays in development, higher costs, and variability in product quality. Globally deployable solutions are needed to ensure reliable potency assessment that supports both commercial scalability and equitable vaccine access.
PATH developed and benchmarked multiple in‑vitro potency methods—fluorescence focus assay, western blot, flow cytometry, direct ELISA, and sandwich ELISA—and then qualified the sandwich ELISA as the lead platform based on sensitivity, quantitative performance, and compatibility with widely available lab infrastructure. Comparative testing across Wuhan and Omicron mRNA‑LNP candidates demonstrated the method is stability‑indicating and transferable. The team prepared an open‑access publication to enable global adoption and harmonization.
Optimize ELISAs for quantification of monovalent and multivalent vaccine antigens
Identify critical parameters for cell culture transfection and establish specification criteria to ensure consistent antigen production.
Optimizing the mRNA transfection process to ensure standardization of antigen expression in selected cell lines
Deployed at scale, the platform could potentially reduce assay time versus cell‑count–based methods by 30–50%, cut method implementation costs by up to 35%, and increase site throughput by ~2× in laboratories constrained by equipment and staffing. These benefits derive from: (i) a qualified, quantitative readout; (ii) simplified workflows; and (iii) use of common ELISA infrastructure.
Assay portfolio developed and evaluated Fluorescence Focus Assay (FFA), Western blot, Flow cytometry, Direct ELISA, Sandwich ELISA (lead platform)
Sandwich ELISA qualified; stability‑indicating and quantitative (Wuhan/Omicron mRNA‑LNP)
Comparative testing confirming concordance with other methods (direct ELISA, western blot, FFA)
BRL advanced from 4 → 6, indicating readiness for GMP validation
Manuscript published: Optimization of an mRNA Vaccine Potency Assay Platform for Global Use (open access)
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PATH Center for Vaccines Innovation & Access
