[Booster vaccination with a diphtheria-tetanus vaccine for dermo-jet with low diphtheria toxoid content]

Indications are provided on how the organization of polyvaccinations against tuberculosis, poliomyelitis and diphtheria-tetanus in school collectivities can be rationalized. 19 persons aged 19-20 years were vaccinated intradermally with 1.5 Lf diphtheria toxoid and 15 Lf tetanus toxoid (contained in 0.1 ml) by means of a single injection with a jet injector (Dermo-Jet). In cases which had not previously been immunized, vaccination with the toxoid doses employed did not induce detectable antitoxin titers. In all cases which had previously been immunized the antitoxin titers after the booster injection were at least 400 times higher than the protection threshold for diphtheria and 1700 times higher than the protection threshold for tetanus. This was also the case in preimmunized cases which had no detectable antitoxin titer before the vaccination. The increase in antitoxin titer was inversely proportional to the prevaccinal titer in the manner of a logarithmic exponential function. It may be concluded from these results that the benefit of a booster vaccination is particularly high in poorly immunized persons whereas it is clearly limited in cases showing a high prevaccinal titer. The well tolerated intradermal vaccination with the jet injector (Dermo-Jet) can be considered as equivalent to the subcutaneous technic. From the point of view of organization (time consumption, problems of sterilization) this method is much preferable to intramuscular or subcutaneous vaccination.