[Study on epidemiological effect of the freeze-dried attenuated live varicella vaccine].

OBJECTIVE: To evaluate the safety and epidemiological effect of the Freeze-dried Live attenuated varicella vaccine. METHODS: A random, double-blind control clinical trial was adopted. RESULTS: In the observation period, the incidence of varicella was 0.8 per thousand in the experimental group and 8.7 per thousand in control group. There was a significant difference (B.P=0.000017). Vaccine effectiveness (VE(%)) was 90.8%, the lower limit of 95%CI was 88.7%. CONCLUSION: The varicella vaccine produced by Changchun keygen biological products co., Ltd. was safe and effective.