IMMUNITY TO TETANUS, DIPHTHERIA AND POLIOMYELITIS IN THE ADULT-POPULATION OF SWEDEN IN 1991

Background During 1990 and 1991 a survey of immunity was carried out i n Sweden. The main purpose was to estimate the level of immunity to di phtheria, tetanus and polio in the adult population. In total, 4800 pe ople, randomly selected according to a stratified, two-stage, sampling plan, were contacted and asked to contribute a blood sample. Of those selected, 70.6% gave a blood sample. Methods Estimates and confidence intervals of the proportion of the population with antibodies exceedi ng some titre was calculated. The population was divided according to sex, year of birth (five age groups) and residence (four regions). Res ults In age groups that were born after the introduction of childhood vaccination, greater than or equal to 90% and 75-90% of people have de monstrable antibodies at a protective level against tetanus and diphth eria respectively Those born earlier, especially women, are poorly pro tected with less than 50% having protective antibody levels for both t etanus and diphtheria. Differences between men and women were particul arly seen in the age groups born between 1930 and 1950. Less than 5% o f the Swedish population lacked the protective level antibodies agains t polio types 1, 2 and 3 respectively. Conclusions Vaccination against tetanus, which can be combined with vaccination against diphtheria, c an be recommended especially to women born before 1950 and with no doc umented previous vaccination. The same recommendation can be given for men born before the 1930s. As regards poliomyelitis, general booster vaccination of the adult population does not appear to be necessary at present.