The use of reference materials is the basis of standardization and quality control of biologicals such as vaccines produced by different manufacturers and lot-to-lot consistency. The aim of this study was to establish a secondary local and national reference standard of adsorbed tetanus toxoid that can be used for tetanus toxoid vaccine potency testing. Concentrated bulk of tetanus toxoid was adjuvanted and aliquoted before lyophilization. Lyophilized product was tested for biological and physicochemical qualities, including moisture content, identity, appearance, antigen content, degree of adsorption, and sterility. The potency of the candidate reference material was calibrated against the 4th World Health Organization International Standard (WHO IS) for tetanus toxoid by two independent laboratories (BioNet-Asia and Thai National Control Laboratory) using the WHO mouse challenge test. A total of 839 vials with lyophilized tetanus toxoid reference material were produced. Potency was estimated at 115 IU/vial [intra-laboratory geometric coefficient of variation (GCV) of 7 tests was 16.5%] and 112 IU/vial (intra-laboratory GCV of 5 tests was 38.6%) at the two laboratories, with an inter-laboratory GCV of 25.5%. The potency of the candidate standard was assigned a value of 114 IU/vial. The candidate reference standard was approved by The Thai National Central Laboratory (NCL) as the Thai national tetanus toxoid reference standard.

参考材料的使用是生物制剂（例如，不同制造商生产的疫苗）和批次间一致性的标准化和质量控制的基础。这项研究的目的是建立可用于破伤风类毒素疫苗效价测试的破伤风类毒素吸附的地方和国家二级参考标准。在冻干前，将浓缩的破伤风类毒素的大部分佐剂并等分。测试了冻干产品的生物学和物理化学性质，包括水分含量，特性，外观，抗原含量，吸附程度和无菌性。由两个独立的实验室（BioNet-Asia和泰国国家控制实验室）使用WHO小鼠激发试验，根据第四版世界卫生组织国际标准破伤风类毒素对候选参考物质的效价进行了校准。总共生产了839瓶冻干破伤风类毒素参考物质。在两个实验室中，效价估计为115 IU /小瓶[7个测试的实验室内几何变异系数（GCV）为16.5％]和​​112 IU /小瓶（5个测试的实验室内GCV为38.6％），实验室间GCV为25.5％。候选标准品的效价指定为114 IU /小瓶。候选参考标准已由泰国国家中央实验室（NCL）批准为泰国国家破伤风类毒素参考标准。