摘要
Objective Long-term seroprotection via the hepatitis A vaccine is essential for the prevention of disease from the hepatitis A virus(HAV).Due to documented difficulties during decade-long follow-ups after receiving vaccines,statistical-modeling approaches have been applied to predict the duration of immune protection.Methods Based on five-year follow-up data from a randomized positive-controlled trial among Chinese children(1–8 years old)following a 0,6 months vaccination schedule,a power-law model accounting for the kinetics of B-cell turnover,as well as a modified power-law model considering a memory-B-cell subpopulation,were fitted to predict the long-term immune responses induced by HAV vaccination(Healive or Havrix).Anti-HAV levels of each individual and seroconversion rates up to 30 years after vaccination were predicted.Results A total of 375 participants who completed the two-dose vaccination were included in the analysis.Both models predicted that,over a life-long period,participants vaccinated with Healive would have close but slightly higher antibody titers than those of participants vaccinated with Havrix.Additionally,consistent with previous studies,more than 90%of participants were predicted to maintain seroconversion for at least 30 years.Moreover,the modified power-law model predicted that the antibody titers would reach a plateau level after nearly 15 years post-vaccination.Conclusions Based on the results of our modeling,Healive may adequately induce long-term immune responses following a 0,6 months vaccination schedule in children via induction of memory B cells to provide stable and durable immune protection.
基金
sub-project of National Major Scientific and Technological Special Project of China for‘Significant New Drugs Development’[2015ZX09501008-004]。
