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Why do we get vaccinated in the shoulder with the Covid19 vaccine?

Those who were vaccinated against the COVID-19 virus but also those who did not observed that the vaccination was done in the shoulder. Specifically, in a shoulder muscle called the deltoid.

Why do we get vaccinated in the shoulder with the Covid-19 vaccine?

At this point you are probably asking yourself what’s so special about this muscle? Not all vaccines are given into the shoulder muscle (intramuscular injection). Some, such as the rotavirus vaccine, are given orally. Others are given just under the skin or subcutaneously, such as the measles, mumps, and rubella vaccine. However, many others, such as the anti-COVID-19, are injected into the muscles.

Why are muscles so important?

Here are the benefits of muscle for vaccination: muscle tissue contains important immune cells, which can recognize the antigen (small segments of the virus or bacterium that are introduced into the body through the vaccine, to stimulate the immune system). In the case of the COVID-19 vaccine (some of them, such as Pfizer or Moderna), no antigen is introduced, since it is a mRNA vaccine. In essence, the messenger RNA vaccine produced by the two companies mentioned above injects messenger RNA into the body in order to create the SARS-CoV-2 virus-specific S-type protein. Immune cells in muscles collect these antigens and transport them through the lymph vessels to the lymph nodes. The lymph nodes contain several immune cells that identify the antigens introduced by vaccination and begin the process of producing antibodies. Lymph nodes are located near the vaccination site. In the case of deltoid vaccination, lymph nodes are found in the underarm area. Muscle tissue keeps vaccine reactions (local inflammation and redness) localized. If the vaccine is given in an area with adipose tissue (fat), the likelihood of more extensive irritation and inflammation increases, because this type of tissue has a reduced blood flow. In addition, it means poor absorption of the vaccine components.

A final argument regarding the area where the Covid-19 vaccine is given relates to the immediate availability of the shoulder for vaccination. Having been vaccinated on our feet would have led to some complications, especially when it comes to filming / demonstrative photography of the vaccination act (joke!).

These being said, it’s everyone’s option to get vaccinated or not… Good luck!