Analysis on the Result of the Virus Titer of Oral Live Poliomyelitis Vaccine Drage′e in Recently 5 Years

We summarized the control results of Oral Live Polimyelitis Vaccine Drage'e virus titer in our Institute from 1994 to 1998,and also analyzed the results.We came to the conclusion that the virus titer of OPV is raised gradually in the recent five years.The mean titer was raised from 6.13logTCID₅₀/human dose to 6.25logTCID₅₀/human dose.At the same time,the stability of OPV was raised in gradual.The differential value between basic titer and average titer of 37℃ 48h decreased from 0.87logTCID₅₀/human dose to 0.63logTCID₅₀/human dose.