What Doctors Don't Tell YouThe diphtheria booster may be ineffective at least one fifth of the time, according to a new study.
To test the effectiveness of the single adult booster, Belgian researchers recruited 176 adult volunteers, all of whom had been immunised during childhood.
>From blood tests, 39 per cent of these subjects were susceptible to diphtheria and 43 per cent were considered immune. The rest had limited immunity.
After receiving boosters, 76 per cent were immune. Of those who were not protected before the jabs, around half remained susceptible. Age was a major determinant of immunity, with older people less likely to have adequate antibodies before or after the booster.
These data suggest that nearly a quarter of adults receiving diphtheria boosters may still be inadequately protected.
Ongoing diphtheria epidemics in Eastern Europeand a worldwide increase in diphtheria cases have raised serious questions about the long term effectiveness of the diphtheria vaccine (BMJ, 2000; 320: 217).
Daniel Redwood DC
Tom Ferguson MD
