Abstract:Objective To prepare a lyophilized reference antigen of recombinant enterovirus 71 vaccine (Hansenula) for the determination of antigen content of recombinant EV-A71 vaccine (Hansenula). Methods Bulk of qualified recombinant EV- A71 vaccine (Hansenula) was selected as the raw material of reference, adding freeze-dried protective agent, then lyophilized to prepared freeze-dried recombinant EV-A71 (Hansenula) vaccine antigen reference, after the calibration on the antigen content, the reference was carried on the freeze-thaw test, stored at 37 ℃, 2-8 ℃ and -20 ℃ for the stability study. Results All the quality indexes of prepared reference met the relevant requirements, and the moisture content was 1.4%. After calibration, geometry mean of reference antigen content was 2 146 U/ml and geometric variation coefficient was 7.2%.There was no significant change in antigen content after repeated freezing and thawing for 10 times. There was no significant change in antigen content for 3 months at 37 ℃.The antigen content remained stable at 2-8 ℃ and -20 ℃ for 30 months, respectively. Conclusion A batch of stable and homogeneous reference antigens were prepared, which could be applied for the determination of antigen content in recombinant EV-A71 vaccine (Hansenula).