RESUMO
OBJECTIVE: To improve the quality of measles vaccine and find out good combination of cultural factors of measles vaccine virus seeds. METHODS: Orthogonal experiments were made to confirm optimized cultural factors. 5 lots of optimized measles vaccine working seed lot were prepared. RESULTS: The titers of the optimized vaccine seed improved significantly (> or = 0.69 +/- 0.35 LgCCID50/1.0 ml, P < 0.05), compared with 5 lots of traditional working seed lot. With these seeds we trial-prepared 5 lots of lyophilized vaccines respectively, the titer and stability met the Chinese Requirements of Biological Products. CONCLUSION: The orthogonal experiment is a kind of good method for optimizing cultural conditions of measles vaccine working seed lot. The yield and quality of measles vaccine can be improved in the optimized working seed lot with high titer and good stability.