Why are vaccines on the arm and not the butt?Count how many “prints” you have

In order to prevent diseases, we have been vaccinated with various vaccines since birth, such as BCG vaccine, hepatitis B vaccine, polio vaccine, DTP vaccine, meningitis vaccine, measles vaccine, hand, foot and mouth vaccine, chickenpox Vaccines, HPV vaccines, and the new crown vaccines vaccinated in recent years, etc.

Some people will leave scars after vaccination, some will not; some people have “vaccine marks” on their arms, and some people do not.

What’s going on here? Let’s talk about “vaccine printing”.

How did the “vaccine print” come about?

There are many types of vaccines:

1. Live vaccines

It is a vaccine made of live virus or bacteria, such as the earliest smallpox vaccine. Because this type of vaccine is equivalent to one infection and has a large reaction, there is basically no such type now;

2. Live attenuated vaccines

As the name suggests, it uses a live attenuated pathogen or a very similar low-virulence pathogen, and the BCG vaccine to prevent tuberculosis is a live attenuated vaccine;

3. Inactivated vaccine

It is to use a complete, killed (inactivated) or modified pathogen so that it cannot reproduce and thus not cause disease, such as the inactivated new crown vaccine used by our country.

4. Recombinant protein vaccine

Not the whole virus, but one or several important parts of the virus, such as the HPV vaccine.

5. In addition, there are nucleic acid vaccines, polysaccharide vaccines, etc.

The immunogenicity of live virus/attenuated live virus is generally stronger than other types of vaccines. After vaccination, the immune response of the human body is also stronger, and it is possible to leave a “vaccine imprint” at the injection site.

Such as BCG, about 3 weeks after inoculation, there will be an inflammatory reaction. The vaccination site is red and swollen, and the middle softens to form a small pustule. After that, the pustule ruptures. After 1-2 weeks after the pus is removed, the scab begins to form, and finally the scab falls off and forms. A circular scar, also known as a “scar”.

What vaccines leave their mark?

Although there are many types of vaccines, there are currently only two that leave a “vaccine stamp”: the smallpox vaccine (also known as the vaccinia vaccine) and the BCG vaccine.

In May 1980, the World Health Organization announced that human beings had eradicated the smallpox virus, and my country cancelled the nationwide vaccination of vaccinia in March 1981.

Therefore, most post-80s, post-90s, and post-00s have not been vaccinated against vaccinia, and there is usually only one “vaccine mark” left by BCG on their arms, while people born before 80 may have two scars on their arms.

Not everyone who has been vaccinated with the above two vaccines will have a “vaccine stamp”, and there are exceptions to scarring according to individual physique. For example, some newborns have less immune response after vaccination, and the scarring may not be obvious And with age, scars will gradually fade, and finally basically invisible.

Why are vaccines on the arm?

Most of the vaccines are injected intramuscularly, that is, in the arm.

In addition, there are also oral vaccines, such as the “sugar pill” vaccine to prevent polio virus; there are also measles vaccines that are administered under the skin.

The arm has become the most common site of vaccination, which is related to the following factors:

1. The fundamental purpose of vaccines is to arouse the body’s own immune response. Remember this pathogen, so that you can respond quickly to eliminate it the next time you encounter it.

The lymph nodes of the human body are a key part of the immune system, and vaccination close to the lymph nodes is more conducive to activating the immune response.

Many vaccines are given in the deltoid muscle of the arm, which is so close to the lymph nodes under the arm.

If the vaccine is given on the thigh, it is not far from where the lymph nodes in the groin gather.

2, Intramuscular injection allows the vaccine response to remain localized.

If it hits fatty tissue, redness and other reactions may be more severe.

The size of the muscle also affects the choice of injection site. Children under the age of three have small arm muscles, so the intramuscular vaccine is usually injected in the thigh, which is close to the groin lymph node.

3. From a convenience point of view,It is also the easiest and most acceptable to hit the arm.

What should I pay attention to when vaccinating?

If you suffer from tuberculosis, nephritis, heart disease, immunodeficiency, etc., you should postpone vaccination, consult your doctor about whether you are eligible for vaccination, and re-vaccinate at a suitable time.

Do not eat warm or hot food or drink within half an hour after the child’s oral polio vaccine.

Pay attention to rest the day before vaccination, try not to stay up late, do not drink alcohol, do not eat spicy and spicy food, and keep your body in the best condition.

Hashtags: Biomedical Vaccine Injections