Tanaka Yoichi, Hamano Sayaka, Ishii-Watabe Akiko, Saito Yoshiro, Kikura-Hanajiri Ruri
Division of Medicinal Safety Science, National Institute of Health Sciences, Kanagawa 210-9501, Japan.
Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Kanagawa 210-9501, Japan.
Mol Ther Methods Clin Dev. 2025 Aug 5;33(3):101549. doi: 10.1016/j.omtm.2025.101549. eCollection 2025 Sep 11.
Assessment of the biodistribution and shedding is required for the development of viral vector-based vaccines. Vector copy number is commonly quantified using digital PCR (dPCR) or quantitative PCR (qPCR). However, the regulatory guidelines for bioanalytical PCR assays have not been released at present. To consider the future setting of acceptance criteria for method validation in a guideline, we aimed to develop and validate a method for quantifying a model adenoviral (Ad) vector vaccine (Ad-hCovHKU1S-2A-GFP) using dPCR and qPCR in biological matrices and assessed its biodistribution in mice. Primers and probes were designed for the region between the sequences of the Ad and HKU1S. Method development and validation were performed using dPCR and qPCR with 1 μg of mouse genomic DNA (gDNA)/reaction. The validation parameters and their acceptance criteria were pre-defined as possible values referred from the literature. Lower limits of quantitation were set as 12 copies and 48 copies/reaction for dPCR and qPCR, respectively. Both dPCR and qPCR met the pre-defined acceptance criteria for intra- and inter-run accuracy and precision. Cross-validation showed similar quantitative results using both dPCR and qPCR. The pre-defined acceptance criteria on dPCR and qPCR may be applicable to the biodistribution and shedding of viral vector-based vaccines.
基于病毒载体的疫苗研发需要评估生物分布和脱落情况。载体拷贝数通常使用数字PCR（dPCR）或定量PCR（qPCR）进行定量。然而，目前生物分析PCR检测的监管指南尚未发布。为了在指南中考虑未来方法验证的验收标准设定，我们旨在开发并验证一种使用dPCR和qPCR在生物基质中定量模型腺病毒（Ad）载体疫苗（Ad-hCovHKU1S-2A-GFP）的方法，并评估其在小鼠体内的生物分布。针对Ad和HKU1S序列之间的区域设计了引物和探针。使用dPCR和qPCR，每个反应加入1μg小鼠基因组DNA（gDNA）进行方法开发和验证。验证参数及其验收标准预先定义为参考文献的可能值。dPCR和qPCR的定量下限分别设定为每个反应12拷贝和48拷贝。dPCR和qPCR均符合预先定义的批内和批间准确性及精密度验收标准。交叉验证表明，使用dPCR和qPCR得到的定量结果相似。dPCR和qPCR的预先定义验收标准可能适用于基于病毒载体的疫苗的生物分布和脱落情况。
