We have recently demonstrated that single shot vaccinations against tetanus and diphtheria do not lead to long-lasting immunity against diphtheria in elderly persons despite administration at 5 year intervals. In the present study we have immunized a group of young adults against tetanus and diphtheria to compare the pre- and 28 days post-vaccination immune responses in the young group with results of the same vaccination performed in an elderly group of a previous study. We also studied protection in both groups 5 years after vaccination. We compared antibody titers at all three time points and also analyzed the T cell responses in both age groups 5 years after vaccination. Before vaccination 9 % of the elderly persons were not protected against tetanus, and 48 % did not have protection against diphtheria. In the young group all participants were protected against tetanus, but 52 % were also unprotected against diphtheria before vaccination. 28 days after vaccination 100 % of all participants had protective antibody concentrations against tetanus and only a small percentage in each age group (<10 %) was unprotected against diphtheria. 5 years later, 100 % of both cohorts were still protected against tetanus, but 24 % of the young and 54 % of the elderly group were unprotected against diphtheria. Antibody concentrations against diphtheria measured by ELISA correlated well with their neutralizing capacity. T cell responses to tetanus and diphtheria did not differ between young and old persons. We conclude that booster vaccinations against tetanus and diphtheria according to present recommendations provide long-lasting protection only against tetanus, but not against diphtheria, independently of age. In elderly persons, the level of protection is even lower, probably due to intrinsic age-related changes within the immune system and/or insufficient vaccination earlier in life.

中文翻译：

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破伤风和白喉加强疫苗接种：对年轻人和老年人白喉的保护不足。


我们最近证明，尽管每隔 5 年接种一次，但针对破伤风和白喉的单次疫苗接种并不能导致老年人对白喉产生持久的免疫力。在本研究中，我们对一组年轻人进行了针对破伤风和白喉的免疫接种，以将年轻组中接种疫苗前和接种后 28 天的免疫反应与先前研究中老年组中进行相同疫苗接种的结果进行比较。我们还研究了接种疫苗 5 年后两组的保护作用。我们比较了所有三个时间点的抗体滴度，并分析了接种疫苗 5 年后两个年龄组的 T 细胞反应。在接种疫苗之前，9%的老年人没有预防破伤风的能力，48%的老年人没有预防白喉的能力。在年轻组中，所有参与者在接种疫苗之前都没有预防破伤风，但 52% 的人也没有预防白喉。接种疫苗后 28 天，100% 的所有参与者都具有针对破伤风的保护性抗体浓度，每个年龄组中只有一小部分 (<10%) 没有针对白喉的保护性抗体。 5 年后，两组人群中 100% 的人仍能预防破伤风，但 24% 的年轻人和 54% 的老年人组没有预防白喉。通过 ELISA 测量的白喉抗体浓度与其中和能力密切相关。 T 细胞对破伤风和白喉的反应在年轻人和老年人之间没有差异。我们的结论是，根据目前的建议，针对破伤风和白喉的加强疫苗接种只能提供针对破伤风的长期保护，而不能针对白喉提供持久的保护，与年龄无关。 对于老年人，保护水平甚至更低，可能是由于免疫系统内与年龄相关的内在变化和/或早期疫苗接种不足。