Test tube experiments suggest that humans paid a high cost for developing immunity to this bug: it may have left us much more susceptible to another retrovirus, HIV.
初步试验发现，我们对这种病毒的免疫力是以极大的代价换来的：为了抵抗它，人类对艾滋病病毒的抵抗力被大幅削弱。
The product is a health food mainly made of chitin. It has been proved through functional test that this product has health function of immunity adjustment and ageing deceleration.
本产品是以甲壳素为主要原料制成的保健食品，经功能试验证明，具有免疫调节、延缓衰老的保健功能。
It is not possible for health authorities to test each and every child for immunity, and there is no harm in vaccinated children receiving an additional dose.
卫生部门不可能对每一个孩子都进行免疫水平检测，而且再次注射的麻疹疫苗对于已经注射过该疫苗的儿童是没有任何伤害的。
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