[The relationships between antitoxic titers determined in a group of young people before and after booster ADT by the in vivo neutralization test. Comparative NT-PHAR evaluations].

The geometrical mean of antitoxic titers determined in a lot of immunized young men who received, 5-7 years before, a booster with diphtheria-tetanus bivaccine, was of 1.54 (x/divided by 10.54) I.U./ml. At one month after another booster, performed with Tetanus toxoid (adsorbed), an increase of 34 times was recorded, the geometrical mean reaching the value of 52.67 (x/divided by 10.42 I.U./ml). The covering coefficients of the minimal protective antitoxin level have increased from 154 to 5267, in the estimation performed at the level of geometrical mean (calculating the ratio between the value of this indicator and that of the protection limit) and from 1623 to 54935, or from 15 to 505, respectively, in the estimations performed at the levels of the limits of the statistical range of one geometric standard deviation (Mg x/divided by D Sg). The study of the relations between pre- and post-antitoxic titers, performed by the linear regression analysis, leads to an equation whose slope evidenced the lower amplitude of the booster titers, along the increase of previous titers. The study of the inter-methods (neutralization-passive haemagglutination) regression allowed to obtain a correlation coefficient, between methods, of r = 0.83 and to perform the transposition of the minimal protective N.T. level (0.01 I.U.) in the terms of passive haemagglutination reaction, at the titer of 160 (0.3 PHAU/ml), for the p less than or equal to 0.05 probability level.