Immunity to tetanus in Finland

A systematic vaccination program including tetanus vaccinations was started in Finland in 1957. It covers the children up to school age very effectively. Antibodies of IgG class against tetanus toxoid were quantified by enzyme-linked immunosorbent assay (ELISA) in random samples from 240 Finnish adults. A protective concentration of antibodies (greater than or equal to 0.01 U/ml) was detected in 98.4% of 18--25-year-olds, in 93.3% of 26--35-year-olds, in 68.8% of 36--45-year-olds and in 83.6% of people over 46 years. In people over 36 years almost one half had antitoxin levels below 0.05 U/ml, which some authors suggest is the lowest level that protects against the disease. There were no significant differences in the mean antitoxin titers between men and women.