Reading this thread, involving exposure to a rabid bat, it says that many people had to receive rabies vaccines. In the old days it was said that you needed a typhoid immunization if you stepped on a rusty nail.
Isn’t that closing the barn door after the horse is out? If you’ve been infected by rabies, how is exposing you more (or to a closely related compound) going to help you? Isn’t your body already preparing it’s immune response? How can a vaccination be retroactive, so to speak?
I think that’s tetanus rather than typhoid and it’ still done today if you puncture yourself or should be done anyway.
As I understand it rabies has a long enough time between exposure and onset for the vaccination to provide immediate antibody production.
First of all, it’s tetanus, not typhoid for ‘rusty nail’ and the old days include today. The idea in that case is to remind your immune system how to fight off tetanus since it has probably forgotten how since your last booster (usually around 14 years old and good for 5-10 years). Tetanus vaccination is a part of routine childhood immunizations in a combination with diphtheria and pertussis (DTaP).
Rabies is a bit different. In that case, you will get a series of vaccinations over a period of about a month to prevent you from contracting the disease after a possible exposure. Rabies is a very indolent (slow moving) infection and it’s possible in this case to get the immune system going after exposure, but before the infection can ‘take hold’ so to speak.
In the case of rabies, it’s because the virus lives in your nervous system, and so never gets exposed to your immune system. If your immune system is primed with a vaccination, it can then detect infected cells and destroy them.
With tetanus, I want to say it’s a toxin you’re fighting, but I’d have to look that up.
Sort of. The bacteria in question (Clostridium tetani) will grow in a wound and then produce the toxin which is what causes all the problems. But the vaccine is meant to keep the bacteria from being able to multiply at all.
Been tehre done that many times on the tetanus shot in an emergency room. SOP for nurses to ask how long since your last one, and then while you hesitate to think about it, jab you in the arm with a new one.
Rabies takes about 3 weeks to develop, so a shot can be helpful there too. Had to find that out the semi-hard way last year too.
Postexposure propylaxis for rabies should always include rabies immune globulin in addition to vaccine.
The immune globulin (antibodies against the rabies virus) can start neutralizing virus while the vaccine begins priming the patient’s own immune system to attack.
For more information, compare passive immunization (administration of immune globulin) to active immunization (vaccination).
Depends on the bite location. The virus enters the local nerve and slowly reproduces its way upstream to the brain. Once it hits the brain, you’re dead. So the farther from your head the bite is, the longer it takes to manifest. Being bitten on the foot is much better than, say, your neck.
WAG
Well, in the case of a vaccine of course the virus is in some sort of weakened state.
So, while your body is slugging it out with the real deal, it encounters the weakened virus, and obviously your immune system doesn’t focus on one foreign agent at a time.
It kicks the weakened virus’ ass fast, developing antibodies along the way. Eventually it tries those same antibodies on the previous invader, and as a great leader once said: “Mission accomplished”.
Just to add, the tetanus infection has nothing to do with the rust on a nail. The bacteria lives in the soil and can be aquired by any cut that is dirty. Rusty nails have nothing to do with it. Puncture wounds are just harder to clean out and more likely to hold the tetanus bacteria long enough to cause a problem.
That is why when you go to the emergency room with a skin wound and cannot give a date as to your last tetanus shot, they give you a new booster anyway.