There are quite a number of asymptomatically infected in the population, and they may discharge hepatitis A virus at certain times and under certain conditions.
无症状感染群中为数不少,一定时期和条件下也可出甲肝病毒,但此时带毒常活动自如,不,因而作为传染源有重要意义。
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He also pointed out other vaccines, such as the common polio vaccine used now, and the hepatitis A vaccine, show that a booster four to six months after the original shot provides a powerful and long-lasting increase in immunity.
他还指出,其他疫苗,如现在使用的普通脊髓灰质炎疫苗和甲型肝炎疫苗,表明在最初注射后四到六个月进行加强免疫可提供强大而持久的免疫力增强。