Why Vaccines Are Not Injected Directly Into The Bloodstream

[Prometheus]

Just now, studiot said:

And did you ever give an intravenous vaccination in that time?

Yes, but that was during a phase 1 clinical trial for a prostate cancer vaccine. Quite atypical. The injection was over a few minutes (can't remember the details).

But i'm not disagreeing with you on anything accept the statement the health professionals receive 'substantial extra training' for I.V administration. It's just not as substantial as it sounds, that's all - a few multiple choice questions, half a day practical session with a drugs calculation test at the end. Let me have my moan, man.

[DrP]

41 minutes ago, Prometheus said:

'substantial extra training' for I.V administration

I don't want to go off topic either but it seems relevant to this as an example of the training people who work in hospitals get. An old friend of mine got a job as a cleaner in the operating theatres after surgery at a nearby hospital.  He said he was appalled at the fact he had absolutely no training for the job. They just gave him a mop and some other equipment and some disinfectant and told him to just scrub around. He went to his bosses and suggested what he thought was a good cleaning schedule...  getting into corners and asking if he should have a certain cleaning schedule and to see if there was anything he HAD to know to do the job that he had not been told. He asked what disinfectants to use and where and what to clean to avoid the spread of super bugs etc. How should he clean the operating table.   He also told them he was concerned about lack of training of the cleaners and their lack of awareness regarding superbugs and the cleaning of surgical theatres (they were just cleaners - not trained to clean medical kit). In the end they suggested he should become the cleaning supervisor and actually provide the training himself for all of the other cleaners (presumably because he seemed to know a lot about superbugs and thought there should be training in place for cleaners of important areas like the theatre and the solitary wards and things).  He walked out in disgust after saying that he could not train anyone at all as he'd received no formal training himself.

Being honest - I think he should have taken the job and taught himself - he is always reading about stuff and self learning. He knew more than they did.

[peterwlocke]

 

 

 

On 4/24/2019 at 5:25 AM, koti said:

 

„Most vaccines should be given via the intramuscular route into the deltoid or the anterolateral aspect of the thigh. This optimizes the immunogenicity of the vaccine and minimizes adverse reactions at the injection site. Recent studies have highlighted the importance of administering vaccines correctly.1–3 Clinical practice needs to reflect considerations about the right length and gauge of needles used to ensure that those vaccinated get the immunological benefit of the vaccines without local side effects”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1118997/

 

 

so what you are saying is that it is better if they have an allergic reaction. cool did not know.

not anti-vax if that sounded like that.

[Carl Fredrik Ahl]

On 4/24/2019 at 2:25 PM, koti said:

This optimises the immunogenicity

Yeah, but WHY?

[koti]

40 minutes ago, Carl Fredrik Ahl said:

Yeah, but WHY?

This is a paragraph below the one you quoted above from the link I gave. Are you even reading the answers were posting?:

”Injecting a vaccine into the layer of subcutaneous fat, where poor vascularity may result in slow mobilisation and processing of antigen, is a cause of vaccine failure1—for example in hepatitis B,2 rabies, and influenza vaccines.3 Compared with intramuscular administration, subcutaneous injection of hepatitis B vaccine leads to significantly lower seroconversion rates and more rapid decay of antibody response.1

Traditionally the buttocks were thought to be an appropriate site for vaccination, but the layers of fat do not contain the appropriate cells that are necessary to initiate the immune response (phagocytic or antigen-presenting cells). The antigen may also take longer to reach the circulation after being deposited in fat, leading to a delay in processing by macrophages and eventually presentation to the T and B cells that are involved in the immune response. In addition, antigens may be denatured by enzymes if they remain in fat for hours or days. The importance of these factors is supported by the findings that thicker skinfolds are associated with a lowered antibody response to vaccines.1,2”

[Carl Fredrik Ahl]

1 hour ago, koti said:

This is a paragraph below the one you quoted above from the link I gave. Are you even reading the answers were posting?:

”Injecting a vaccine into the layer of subcutaneous fat, where poor vascularity may result in slow mobilisation and processing of antigen, is a cause of vaccine failure1—for example in hepatitis B,2 rabies, and influenza vaccines.3 Compared with intramuscular administration, subcutaneous injection of hepatitis B vaccine leads to significantly lower seroconversion rates and more rapid decay of antibody response.1

Traditionally the buttocks were thought to be an appropriate site for vaccination, but the layers of fat do not contain the appropriate cells that are necessary to initiate the immune response (phagocytic or antigen-presenting cells). The antigen may also take longer to reach the circulation after being deposited in fat, leading to a delay in processing by macrophages and eventually presentation to the T and B cells that are involved in the immune response. In addition, antigens may be denatured by enzymes if they remain in fat for hours or days. The importance of these factors is supported by the findings that thicker skinfolds are associated with a lowered antibody response to vaccines.1,2”

Yeah I understand that injecting it to fat isn't good, the enzymes can denature the antigen since it takes so long for the antigen to be processed, but I don't understand what the problem is with injecting it directly into the bloodstream. But I give up, I won't understand, but thanks for all the answers.

[koti]

33 minutes ago, Carl Fredrik Ahl said:

Yeah I understand that injecting it to fat isn't good, the enzymes can denature the antigen since it takes so long for the antigen to be processed, but I don't understand what the problem is with injecting it directly into the bloodstream. But I give up, I won't understand, but thanks for all the answers.

If you take a pill you swallow it although the pill would work just fine if you stuck it in a different orifice than your mouth.

[Sensei]

3 hours ago, koti said:

If you take a pill you swallow it although the pill would work just fine if you stuck it in a different orifice than your mouth.

Pill are designed to slowly release drug.

https://en.wikipedia.org/wiki/Modified-release_dosage

e.g.

"A floating system is a system where it floats on gastric fluids due to low-density. The density of the gastric fluids is about 1 g/mL; thus, the drug/tablet administered must have a smaller density. The buoyancy will allow the system to float to the top of the stomach and release at a slower rate without worry of excreting it. This system requires there are enough gastric fluids present as well as food.[4] Many types of forms of drugs use this method such as powders, capsules, and tablets.[19]"

They are designed to be ingested. Covered by a layer which is dissolved by the stomach.

 

[CharonY]

4 hours ago, Carl Fredrik Ahl said:

Yeah I understand that injecting it to fat isn't good, the enzymes can denature the antigen since it takes so long for the antigen to be processed, but I don't understand what the problem is with injecting it directly into the bloodstream. But I give up, I won't understand, but thanks for all the answers.

Perhaps the part that confuses you. In order to maximize immune response, you want the antigen to be presented for a longer time so that it will be properly recognized by the immune system. This is what has been referred to as depot effect in this thread. As I mentioned, the original assumption was that releasing it directly in the bloodstream would lead to relatively fast clearance, thus minimizing the response. The only way to increase the response was to increase concentration, which can be risky. As such vaccines were developed to be released more slowly via intramuscular injection, with the added benefit of minimizing discomfort and adverse effects (as already mentioned). The development of adjuvants has provided alternatives. The adjuvants can now provide the desired depot effect. However, since there are no obvious benefits in IV delivery under normal circumstances, it is generally not done. So to re-iterate, using adjuvants that provide depot effects IV delivery is feasible. But it is not advantageous, has higher risk of issues and requires additional protocol development. So it is generally not done for routine vaccination.

[FreeWill]

If you inject the vaccine in the blood stream, the antibodies would reach the lymphatic system "too fast", increasing the risk of adverse effect (anaphylactic shock) and decrease the effectivity of the vaccine, since it will be a very short impact which is not enought for the lymphatic system to learn to respond.

[Iberian Wolf]

Probably because of the coagulation it would cause in the blood stream.

Maybe the doctors dont want to risk peoples lives to make the process faster.