Diphtheria Can't Be Stopped by Vaccination!

Dmitriy K. Yuryev (Posted to bionet.virology and bionet.immunology on 15-16 May 96.)

Strictly saying, diphtheria vaccine is a not a true vaccine; it belongs to a family of so called toxoids. It boosts immune response not against the microbe itself but against its toxin (which actually causes all symptoms of the disease). Such immunity inactivates toxin and relieves the symptoms of disease (almost excluding lethal cases) if it is caught soon after vaccination. But the obvious trouble is that this vaccine does absolutely no harm to microbe itself, so it can not hinder its multiplying nor diminish probability of catching infection.

Obviously, for this type of vaccines decline of reported (grave) cases of diphteria after starting mass immunization can not be taken as a proof of their ability to stop epidemic. Such decline is defined by the fact that significant part of epidemic becomes "invisible" for medical statistics: asymptomaticl and mild cases of diphteria are simply not registered. Yet, as far as I know, there are no other proofs.

Several recent reviews (Science, 10Mar.95, 267:1416; JAMA, Apr.95,273(16):765) gave a reason to think so. First, the style of these papers leaves no doubt that using word "vaccine" as a name for diphtheria toxoid is officially considered as a sufficient proof of its efficacy in stopping epidemic. Second, announcing in these papers the obviously unattainable recommendations about necessity to ensure 5-fold (!) vaccination of 95% population to stop epidemic directly imply that practice clearly shows serious problems in stopping diphteria epidemics with toxoid.

Juxtaposition of these two monstrously incompatible points was actually the only reason for me to write this note. I have no specific competence in diphtheria nor much interest to look any further. So, I would be very glad if somebody is interested to investigate this theme. I can't believe that this problem was never discussed at all. More likely, it is possible to find some discussions dated by the time of institution of diphtheria vaccination. I guess, there had to be people who worked on developing regular vaccine against diphtheria who had no reason to "disregard" intrinsic flaws in idea of toxoids.

The most important practical consequence of this interpretation is that if diphtheria toxoid is really unable to stop epidemic then talking about "herd immunity" against diphtheria is most absurd. And, therefore, prophylactic mass immunisation against diphtheria is absolutely meaningless until the epidemic has been started in close neighborhood.

And, finally, it appears worth to be stated directly that writing this note was not possible without uneasy suspicions that vaccinology is governed by idiots.