O983 - Active Immunization Against Tetanus Infection with Refined Tetanus Toxoid

This study compared unrefined tetanus toxoid and also a refined version, precipitated with alum (aluminum potassium sulfate) in guinea pigs. The former gave 0.5 units antitoxin after 6 months, and the latter 1 unit after 3 months. They conclude the latter is better (though it doesn't quite seem like a good comparison to me).

Then they used this refined toxoid to immunize 30 people. None had reactions to it, local or general, which is good. Their antitoxin went from as much as 0.0005 to up to 0.04 units in 90 days. After a 2nd dose, levels got up to 9 units, but were widely variable between people. The highest levels 1 and 2 years after the 2nd dose were 0.4 and 0.35 units, respectively; high enough for protection, they judged.

"The amount of antitoxin found in the serum of human beings thirty days after receiving a second dose of the toxoid was considered to be sufficient to protect them by giving a third dose of toxoid, on injury, instead of a prophylactic dose of tetanus antitoxin."

There was some variation too on whether it lasted a whole 2 years protectively. It seemed to depend more on the individual's general health than on age.

The authors state that the Societe de Chirurgie of Paris committee recommends:

"vaccination against tetanus [is] the best method to decrease the mortality. The vaccine (anatoxin of the Pasteur Institute) is harmless, not being followed by any local or general reaction. The vaccination should be repeated every year or two...In war, vaccination should be made obligatory."

The authors recommend this vaccination for soldiers and others who regularly get injured (farm workers, etc), and also for pregnant mothers:

"The antibodies contained in the placental circulation before birth and the antibodies contained in the mother's milk, afford protection to the new-born child."

And the final recommendation is that if a person has been vaccinated with toxoid and gets injured (more than 1-2 years after the vaccination) they should receive another dose of toxoid to rapidly stimulate a response, just in case. But if they haven't received any toxoid doses, they should get toxoid and also a protective amount of antitoxin serum, because the toxoid won't stimulate a response in time, if necessary.

So that's what they say.

Reference:

Bergey, D. H. & Etris, S. Active Immunization Against Tetanus Infection with Refined Tetanus Toxoid. J Immunol 31, 363–371 (1936).