Seed History and In-process Control for Freeze-dried BCG Vaccine Produced in Taiwan
Wei-Cheng Lian、Wen-Chin Hsieh、Hui-Ching Yang、Yi-Wen Lo
2012 Vol.28 NO.1
Correspondence Author： Wei-Cheng Lian
Tokyo 172 strain had been selected as seed for BCG vaccine production in Taiwan since 1979. Five lots of the seed were presented by Statens Serum Institut in Denmark to Taiwan during 1981 to 1991. These master seeds were originally prepared by Japan BCG laboratory in 1960. Currently, the working seed lot was established from lot B of master seed in 1993. This working seed has been employed in vaccine manufacture until now. The BCG vaccine is supplied for 10, 30, 50, 100 infants use in amber ampoule filled with BCG and sodium glutamate. Taiwan Centers for Disease Control provides 700 thousand doses of freeze-dried BCG vaccine for Expanded Programme on Immunization every year. The specification of BCG vaccine on potency test is above 15x106 colony forming unit/mg/ml. For in-process control, 16 testing items were utilized to assure the consistency of manufacturing process for the quality of BCG vaccine. The results of in-process control were summarized from batch records as following. The average weight of harvested semi-dry BCG pellicle from three consecutive passages after one-week growth was estimated as 0.81g per 100 ml Sauton medium. The measured optical density at 470nm for intermediate product was 0.18 on average. Moreover, two other parameters were used to verify the reliability of manufacturing process. Ratio of semi-dry BCG weight to 1% sodium glutamate volume, 0.95% (weight/volume) was found for final bulk preparation. The BCG survival rate after lyophilization was above 30% by viability counting. The efficacy and safety of BCG vaccine produced in Taiwan were discussed in this report.