Tetanus immunity in elderly people.

The aims of this study were to document the level of tetanus immunity in elderly people; to assess the value of immunization history in predicting tetanus immune status and to determine the response to tetanus immunization in elderly people compared with younger subjects. One-hundred day-hospital attenders (group 1), 100 long-term-care residents (group 2) and 50 young subjects (group 3) were recruited. Protective titres of tetanus antitoxin antibodies were detected in 20% of group 1, 45% of group 2 and 80% of group 3. Tetanus immunization history was a poor predictor of immune status in older people with a positive predictive value of 50% and a negative predictive value of 76%. The response to tetanus immunization was slower and of lower magnitude in older people. However, 36 of 37 older subjects developed protective levels of tetanus antitoxin antibodies on completion of a primary immunization programme.