Why are vaccines injected into veins and not arteries?

Question

I know that veins are superficial thus easier to spot is one reason. And the high blood pressure in arteries also can be another reason... but can any one confirm whether my theory that if vaccines are injected into the artery then they will be used up for energy or something as they reach an effector or muscle, but if injected into the vein it will be eventually carried to the heart from where it will be spread to the whole of the body?

Answer 1

Actually, it's the same reason why phlebotomists draw blood preferentially from veins.

Arteries experience both extreme highs and lows of blood pressure, being much more closely and directly connected as they are to the heart. Veins, on the other hand, are largely shielded from these variations by filtering through capillaries and the like first.

After you give blood, you have to hold up your arm for about thirty seconds and apply gentle pressure, and it will usually clot right up. If an artery has been penetrated, however, it would take minutes for a clot to form and you're much, much more likely to get a lot of bruising and the like. It is quite possible that it NEVER clots normally and you bleed to death instead (unless you're near some place that can take more drastic action).

As for being metabolized... it's not like vaccines are made of some readily digestible substance. Often it's just a weakened or killed form of the the microbe itself. The only thing that would 'eat' it when its in your blood stream would probably be parts of your immune system anyway. The same goes for the idea of being filtered out by the kidneys or liver - if it were this easy to get rid of disease particles, none of us would ever be sick. Likewise, many vaccinations leave measurable viral loads in your bloodstream for months.

Though it's true that many vaccinations are administered just under the skin and into muscles instead of in either veins or arteries, the reason for this is to slow down exposure. Even penicillin can cause very dramatic changes if you receive it too quickly; rapid introduction of a lot of disease particles into the bloodstream is sometimes an invitation to whole-scale system shut down from an immense immune over-reaction. Using these other routes allows your system to adjust slowly to the vaccine (or other medicine).

See link 1 (if you can handle the medicalese) page 3 for a description of exactly why one particular vaccine is given in the way it is.

Answer 2

some drugs and vaccines need to be released on the body slowly than others. In an attenuated vaccine, live virus particles with very low virulence are administered. They will reproduce, but very slowly. Since they do reproduce and continue to present antigen beyond the initial vaccination, boosters are required less often. These vaccines are produced by passaging virus in cell cultures, in animals, or at suboptimal temperatures, allowing selection of less virulent strains, or by mutagenesis or targeted deletions in genes required for virulence. There is a small risk of reversion to virulence, this risk is smaller in vaccines with deletions. Attenuated vaccines also cannot be used by immunocompromised individuals.The latest developments in vaccine delivery technologies have resulted in oral vaccines. A polio vaccine was developed and tested by volunteer vaccinations with no formal training; the results were very positive in that the ease of the vaccines increased dramatically.

Answer 3

I have never had a vaccine injected into a blood vessel..usually get it in a meaty muscle like the upper arm or the butt...that way it can diffuse intot he system slowly and not be a shock to the system

Answer 4

Vaccines are never injected into veins or arteries, if they were they would go into the liver and be cleared from the body within three minutes rendering them useless. Vaccines are administered subcutaneously, intramuscularly or nasaly.

Answer 5

Yeah, I think it's because you want it to go to the whole body. If you put it in an artery, it's only going to go to one part of the body.