A study of the factors influencing tetanus immunity in Israeli male adults.

In Israel the immune status of the adult population is largely unknown, because many adults have immigrated from various countries and have no reliable record of immunisation. The Israel Defence Force has implemented a preventive booster immunisation schedule for all its members. The immunity of the adult male population as well as the factors contributing to it were measured and 77.3% found to have sufficient tetanus antibody for protection. The antibody titres in the 3241 subjects studied were found to depend on age. In the older age groups (45-54 years) over one-third had less than 0.01 IU/ml, but even among those of 21-30 years 14% were 'unprotected', if 0.01 IU/ml is taken as the threshold value. Apart from age, the only other contributing factors identified were the occupation as a civilian, education and the number of years since the last immunisation. In our view, the findings call for an immunisation schedule based in each individual country on population serosurveys.