第一个研制出的甲型肝炎疫苗(Havrix)已在瑞士和比利时市场销售。从1988年起,研究人员用这种由灭活病毒合成的疫苗在18个国家对26000名志愿者(其中3/4儿童)进行了67次临床实验,评价其免疫源性和无害性。这种疫苗分两次注射,间隔2星期或4星期,6个月或12个月再追加一次,每针相当于720单位的酶联法抗原。第一次注射后血清转换率约为95％,第二次注射后接近 The first Hepatitis A vaccine developed (Havrix) has been marketed in the Swiss and Belgian markets. Since 1988, researchers conducted 67 clinical trials of 26,000 volunteers (three quarters of them children) in 18 countries with this vaccine made from inactivated viruses, evaluating their immunogenicity and innocuity. The vaccine is administered in two injections at intervals of 2 weeks or 4 weeks, 6 months or 12 months, and each needle is equivalent to 720 units of enzyme-linked antigen. After the first injection, the seroconversion rate was about 95%, approaching after the second injection