How long does the period of efficacy of second liver vaccine have?

Our country is current and clinical use second liver vaccine is gene project vaccine, it is a kind of safe and effective goods, side effect is little. After liver of second of human body have an inoculation is vaccinal, produce antibody through active immunity means, make human body gains the immune strength of pair of second liver. Statistical data makes clear, antibody of surface of liver of second of the human body after vaccinal second liver is vaccinal (fight one HBs) to turn positive rate is in 95% above, protect effectively period in 5 years of above, antibody drop is spent taller, immune force is more powerful, immunity protects duration to also grow more. But also few number person is in after vaccinal second liver is vaccinal, of the generation inside body fight - HBs drop is spent very low, short of protects a value, be affected with respect to what cannot prevent second liver virus effectively so and duplicate. Additional, after second liver vaccine is vaccinal, fight - HBs follows time elapse, drop degree can drop gradually, should fight - HBs drop is spent fall to be worth to protection the following when, also have immune power to second liver virus no longer. Accordingly, to assure to prevent the effect, after vaccinal second liver is vaccinal, should exsanguinate assay, check 2 half-and-half, if fight - HBs shows masculine gender, show vaccinal success, still should check at the same time fight - HBs drop is spent. If fight - HBs drop spends highest value to be 10 ～ 100mIU/m1 only, best 1 times in the multiple cropping after 6 months; is fought - when HBs drop spends highest value to be 101 ～ 1000mIU/ml, should at first the 1 ～ after have an inoculation inside 2 years answer measure fight - if HBs; is fought - HBs is when 1001 ～ 10000mIU/ml, should be in 2 ～ inside 4 years answer measure; to should be fought - when HBs is more than 10000mIU/ml, but in 4 ～ inside 6 years answer measure; to be fought when discovery - HBs drop is spent under multiple cropping answers when 10mIU/ml, multiple cropping still undertakes by the dosage that plants first and time plan. What Gao Di spends arise to fight after still having vaccine of liver of second of have an inoculation of small number of people - HBs, but still contracted hepatitis, is this why? Because second liver virus is a kind of virus that mutates highly,basically be, after it produces mutation, can turn the virus of new structure, new property into mutation body, the antibody inside former put oneself in another's position does not have immune force to new mutation individual plant, lost precautionary action. Have an inoculation of second liver vaccine is the reliable method that prevents second liver, but also not be absolutely with get sth done once and for ever. Have an inoculation must examine after have an inoculation the effect and fight - HBs drop is spent, and the basis is fought - HBs drop spends a circumstance timely answer measure, should drip degree when be less than protection to be worth, want seasonable reseed, make often keep effective inside body fight - HBs drop is spent, such ability prevent second liver virus effectively to affect, achieve the goal that prevents second liver truly. (the exercitation edits: Plum apricot)