5 Questions About Diphtheria
What is it and where does it come from?
Diphtheria has been known to humanity for a long time — even Hippocrates mentioned it in his treatises in the 4th century BCE. Of course, against the backdrop of other epidemics in the Middle Ages, diphtheria looked somewhat faded, mostly killing small children and being one of the main causes of child mortality. However, adults also suffered severely — in the 17th–18th centuries this tiny bacterium (Corynebacterium diphtheriae) swept entire families in Europe.
With the invention of the diphtheria antitoxin and vaccination against diphtheria, developed countries in the 20th century almost got rid of this disease. The diphtheria epidemic in the 1990s in the territory of the former Soviet Union became a stark example for other countries, underscoring not only the importance of vaccinating children but also timely booster vaccination for adults.
Today diphtheria is not uncommon in less developed countries, in refugee camps, and in areas where people live in poverty and crowding. For comparison, according to the CDC, from 2004 to 2017 there were 2 cases of diphtheria diagnosed in the United States. Globally, according to the World Health Organization, 7,100 cases of diphtheria were recorded; in Ukraine for the current 2019 year — 20 cases.
Given that the percentage of timely vaccinated adult population in Ukraine is currently quite low, concerns about this are entirely legitimate.
There are many diseases, all scary — what makes diphtheria scarier?
When diphtheria begins, it is not easy to immediately distinguish it from a cold or tonsillitis. And who among us would rush off for a culture test at the slightest sore throat? Therefore, carriers of the disease may still contact other people for some time and continue to spread the pathogen. By the way, the infection is transmitted through airborne droplets and survives well in the environment, for example on household items or toys, for quite a long time.
Corynebacteria form dense membranes on the upper respiratory tract, which rapidly grow and cause death by suffocation. This is especially critical for small children.
In addition, diphtheria Corynebacteria produce a toxin that affects mucous membranes, the myocardium, kidneys, and the nervous system. Delays in administering antitoxin can be critical, because antitoxin interacts only with free toxin and is not effective against toxin that has already bound to tissues.
Why might antibiotics not help?
First, diphtheria Corynebacteria, like other microbes, can also “fall into sin” and over time develop antibiotic resistance.
In addition, bacteria in a biofilm are significantly more resistant to antimicrobial agents than bacteria in suspension. And according to some data, the effect of low antibiotic doses may even strengthen biofilm formation.
“I don’t want a vaccine, if I get sick I’ll have antitoxin…”
Sometimes one may encounter the view that vaccination is unnecessary if there is antitoxin and it can be used for treatment if the disease occurs.
If such reluctance arises for someone due to “Indian vaccines,” we should immediately note that antitoxin is most likely of the same origin. But the risk of side effects and complications would be much higher (regardless of the country of origin of the product). Because antitoxin is a purified fraction of horse blood plasma and its administration itself is associated with a number of risks, such as serum sickness, and a higher likelihood of allergic reaction or anaphylactic shock, compared to vaccines.
To obtain this preparation, horses are injected with diphtheria toxin for a certain period, researchers wait for an immune response, draw their blood, isolate the needed immunoglobulins, and package them in vials.
Vaccine production, on the other hand, occurs “in a test tube”: the bacterial culture is grown, the toxin is isolated and purified, and treated so that only the part of the molecule responsible for generating immunity remains (i.e., the anatoxin, which is part of vaccines and does not exhibit toxic properties).
And if vaccine development can be planned according to the vaccination schedule, predicting how much antitoxin might be needed and how many horses would need to be mobilized for this in the event of an outbreak — that is not a simple task.
About booster vaccination
Recall that according to the vaccination schedule, vaccination against diphtheria is required at 2, 4 and 6 months, 1.5, 6, 16 years and thereafter — at least every 10 years.
If for some reason booster vaccination in adulthood was not carried out, but at least three doses were received in childhood to restore immunity, one injection is enough.
If your vaccination status is unknown, you should receive at least three doses of the vaccine with a clear interval: first dose, after a month the second, and six months after the second — the third.
Photo by Fabian Burghardt on Unsplash