I was born, and I got vacinnes for polio, mumps, measles and rhuebella. I got some follow ups throughout grade school, and now I am set, I think, except every ten years I have to get a tetnis booster.
Why do I have to get Tetnis boosters my whole life, when most other things you just get once or with a booster or two, but all within a couple of years?
Does the tetnis keep evolving or something?
Live vaccines usually induce a stronger immunity than killed vaccines, for one thing. When you receive a tetanus vaccine, you’re not being vaccinated against a bacterium, but against the toxin the bacterium produces when it infects a wound. The vaccine is a small dose of the toxin.
Also, your immune system “forgets” its exposure to a vaccine (or to an actual infection) over a period of decades. But some organisms you get continually re-exposed to throughout the course of your life (like chickenpox, or rubella), or you may be exposed to closely related organisms which cause an immune reaction that also works against the original bug you were vaccinated against as well as to the new one. These exposures serve as natural “boosters”, insuring your immunity doesn’t wane. You generally don’t experience such natural exposures with tetanus.
Well … almost right. 
A person receives tetanus toxoid. Information (PDF) re toxoid here
Specifically, tetanus toxoid is produced by processing cultures of C. tetani. Tetanus “vaccines” are older than any Doper (unless we’ve got some over 75)! :eek: The toxin would produce the same muscle spasms, if injected, as an infection would, though probably not fatal (as an untreated infection would be).
Here is an early history of tetanus prevention in the US military.
A person who lives a sedentary, indoors life has a significantly smaller probability of exposure … unless they have pets, particularly pets which have access to outdoors. However, it is far safer to have your regular boosters, regardless of lifestyle.
For the interested person, here is a big wad of information.
Very interesting. Thanks for the links. I have a few more questions though:
[Quote]
Following a wound, to produce rapid levels of circulating antibody, a doctor may administer a specific antitoxin (human tetanus immune globulin, TIG) if the individual does not have an adequate history of immunization.[\quote]
What is the antitoxin? Is it just a large dose of antibodies made by a horse or something?
Secondly, this is a bacterial disease. I looked up the CDC’s recommended immunization schedule and about half the diseases are caused by bacteria and half are caused by a virus. Is there any difference in the way a vaccine works on these two types of infections?
Pretty much, yep.
Not really. There may be minor differences in how the body attacks the microbes, but the vaccines do basically the same thing.
Vaccines are basically of two kinds. One is “killed”, which means that the entire (dead) virus is in a suitable medium, probably with adjuvants. The other presents proteins (from the surface of the bacteria or viruses). In both cases, your immune system finds these alien substances, and processes them. At the end of the line are the antibodies (i.e., yet more proteins, but ones that are custom-designed to attack the particular proteins from the vaccine), which are kept in circulation in your blood.
How long your body continues to make these antibodies depends, at least in part, on how often you come in contact with the organism. However, your body retains the “plans” for the antibody in certain reservoirs (I’m not going to give an immuno seminar here, sorry, if only because I would have to do a LOT of review to be sure I didn’t say something half-right). This is why the CDC said that anyone who had ever had a smallpox immunization would retain some defenses against it.
There is a lot of information out there. “Google is your friend.”
Sorry for the delay in responding. I’m not going online everyday right now.