Why are the “butt shots” we often received when we were young less common now?

Review expert: Qu Bo, chief physician of general surgery, Yangtze River Shipping General Hospital

After finally saying goodbye to the hot summer and welcoming the cool autumn, the epidemic has begun to emerge again, spreading in many places across the country, which makes people tremble with fear. Recently, the editor has been busy persuading people to get vaccinated, including the elderly at home and the girlfriends who were delayed in having children before.

During a casual chat, the editor discovered that a friend was very resistant to vaccination. After asking in detail, he found out that it was the psychological trauma left by the buttocks injection he received when he was a child.

When you see this scene, do you feel a slight tingling sensation in your arm?

Source: pixabay

In fact, many vaccines are no longer injected into the buttocks, but are basically injected into the arm. Why is this so? Let me tell you in detail~

Where is the vaccine administered?

"Injection" is clinically called "injection". Clinically, it is divided into subcutaneous injection, intramuscular injection, intravenous injection, intradermal injection, etc. according to the injection site. Among them, most vaccines are mainly injected by muscle.

Comparison of injection angles for different injection types

(From left to right: intramuscular injection, subcutaneous injection, intravenous injection, intradermal injection)

Source: Wikipedia

There are generally two types of intramuscular injections, one is the buttocks injection, and the other is the deltoid muscle injection. Why are these two places chosen for vaccination? First, we need to understand the process of human immunity formation.

Source: pexels

When human immune cells encounter antigens introduced by vaccines (including small amounts of viruses and bacteria), they transport the antigens to our lymphatic vessels. When the lymphatic vessels encounter immune cells carrying antigens, they further transmit them to the lymph nodes. Lymph nodes are an important part of the human immune system and contain more immune cells. When lymph nodes receive antigen information carried by immune cells, they will produce an immune response and produce antibodies. This process is the immune process. Therefore, when injecting the vaccine, in order to better deliver the antigen, it is necessary to choose an area that contains immune cells and is close to lymph node clusters.

The human muscle tissue contains important human immune cells. Common intramuscular injection areas include the deltoid area of ​​the upper arm, which is close to the lymph nodes under our armpits, and the buttocks area, which is closer to the lymph node clusters in the groin. In addition, the muscles in these two areas are relatively thick, so it is not easy to injure bones and deep blood vessels when the needle is inserted.

Deltoid muscle injection

Source: pexels

So why are buttock injections less common now? There are three reasons.

First, injection pain in the buttocks is obvious. The needles of previous injection equipment were thicker, and they were worn out due to repeated use, which made the injection experience very poor and painful. There is more fat tissue in the buttocks, and in order to inject the vaccine into the muscle tissue of the buttocks, the needle generally needs to be inserted into the buttocks skin 2-3cm deep. Compared with the upper arms and legs, the wound caused by injection in the buttocks is larger, which will cause greater and longer-lasting pain.

Although disposable syringes are now popular, people are still reluctant to endure this "hardship".

Source: Baidu Encyclopedia

Second, buttocks injections are prone to complications. The buttocks contain more sciatic nerves, so the injection risk is greater. Secondly, long-term injections can easily lead to muscle hardening or even atrophy.

The third is the privacy issue of vaccination. When vaccinating, the psychological feelings of the vaccine recipients must also be considered. For example, large-scale vaccinations such as the new coronavirus vaccine are generally given in public places. If the buttocks are injected, the scene is not very elegant, and I believe many people will not be happy to be vaccinated.

So will butt shots completely disappear from our lives? No.

Although the arms can also be injected intramuscularly, the muscles there are thinner, so only small doses of vaccines can be injected. If you want to inject a large dose of vaccine, you still have to choose a buttock injection. In addition, for some drugs, because the muscle tissue in the buttocks is looser and has more blood vessels than the upper arms and legs, it is helpful for the absorption and utilization of drugs, so buttocks injections are also chosen, such as progesterone, vitamin A, glucocorticoids, and streptomycin for the treatment of tuberculosis.

Vaccination options for different populations

Some people may wonder, since infants and children have less muscle mass, will the vaccination method be different from that of adults? The answer is yes.

Generally, for people over three years old, it is recommended to get the vaccine in the deltoid muscle of the upper arm . For children under three years old, since their limb muscles are not yet fully developed and their muscles are smaller, it is easy to injure the bones during injection, so the vaccine is given in the thigh muscle .

Source: pixabay

With the continuous advancement of medical technology, drugs are also being updated and upgraded. Many vaccines that previously required buttock injections can now be injected into the arm.

In short, whether it is a buttock injection or an arm injection, it is for better health protection. Follow the doctor's instructions for injections and seek help from the doctor in time if there are any problems. There is no need to be afraid~