[Some experimental data on the seroprophylaxis of tetanus].

The survival time of tetanus heterologous antitoxins, crude or digested, has been controlled by indirect haemagglutination (I.H.A.) and neutralization tests in guinea pigs and rabbits. Digested antitoxins are demonstrable in guinea pigs up to the 8th day, in rabbits only during the first day. They reach the highest level 24 hours after the injection: tested with I.H.A. show a good correlation with the quantity of injected antitoxin. In the sera of three wounded subjects, treated with Ig or digested horse antitetanic serum, after 24 hours the I.H.A. test was negative, while the neutralizing antibody titer was equal to 0.1/0.01 I.U./ml. These contrasting results are probably due to circulating Fab' gragments from decaying tetanus antitoxins.