| pubmed-article:7010803 | pubmed:abstractText | It was found that 61 per cent of ageing persons (average age 73 years) had no protective concentrations of tetanus antitoxin in their serums. After active immunization with a vaccine (tetanus toxoid) the increase of the tetanus antitoxin concentration was slower and lower in old age compared to the young age. | lld:pubmed |
