Cell-Based Relative Potency Assay Assessed for RSV Vaccine Development

Preclinical and phase 1 clinical trial results suggest an mRNA vaccine targeting the respiratory syncytial virus (RSV) F protein holds promise, authors reported in the Journal of Pharmaceutical and Biomedical Analysis.

RSV is a significant cause of severe lower respiratory tract infections globally. Developing a safe and effective RSV vaccine has been a challenging task, but there have been recent advancements in vaccine technology, researchers said. 

“In recent years, there have been significantly increased interests in mRNA vaccines due to a number of important attributes these vaccines possess compared to traditional vaccines,” researchers said. 

The RSV vaccine V171’s mechanism of action involves the formation of lipid nanoparticles (LNP) encapsulating the mRNA during the production process. This encapsulation serves to protect the mRNA from degradation and facilitates its delivery into mammalian cells. Inside the cells, the mRNA is translated into RSV F protein, eliciting both humoral and cellular immune responses. 

To support phase 2 development of the vaccine, a cell-based relative potency assay has been developed. The assay considers the inherent variability in biological test systems, making it more robust than an absolute measure of potency, researchers said. The assay demonstrated excellent linearity, with a relative bias ranging from 1.05% to 5.41%, and intermediate precision of 11.0%. By targeting a relative potency range of 25% to 250%, the assay has proven effective in testing process development samples, formulation development samples, drug product intermediates, and drug products in support of phase 2 development for the RSV mRNA vaccine, researchers said.

The preclinical and phase 1 results indicate the RSV vaccine V171 is a promising candidate and has the potential to address the significant burden of RSV-related infections worldwide, researchers said. They added that further evaluation in clinical trials will be crucial to assess the vaccine's safety, immunogenicity, and efficacy in a larger population.

Reference:
Li HH, Xu J, He L, et al. Development and qualification of cell-based relative potency assay for a human respiratory syncytial virus (RSV) mRNA vaccine. J Pharm Biomed Anal. 2023;234:115523. doi:10.1016/j.jpba.2023.115523