人到年老时免疫功能也像其它生理功能一样逐渐衰退。对老年人的免疫系统进行研究十分重要,因为它是保护机体避免外界有害因素侵袭的重要系统。使免疫功能衰退的过程减慢也许有助于减轻老年病的危害或推迟老年病的发生。Roberts-Thomson用若干种抗原给80岁以上的老年人作皮内接种,然后追踪观察两年并统计在这两年内的死亡率。结果发现,对所有抗原均无反应,或仅对一种抗原有反应的所谓“无反应”的老年人中,两年内死亡人数占80％。而在至少对两种抗原有反应的老年人 Immune function also gradually declines like other physiological functions when people are old. It is important to study the immune system of the elderly because it is an important system that protects the body from the harmful effects of outsiders. A slowing down of the immune system may help reduce the risk of geriatric diseases or delay the onset of geriatric diseases. Roberts-Thomson used several antigens to vaccinate the elderly over 80 years of age, followed by two years of follow-up and statistics of death rates over the two years. As a result, among the so-called “non-responsive” elderly who did not respond to all the antigens or only one of the antigens, 80% died within two years. And in the elderly who react to at least two antigens