The fact that the new crown vaccine was not administered to the deltoid muscle is not a cause for undue stress, as it can also elicit an immune response from the body. Even if the vaccine is not delivered to the deltoid muscle, the vaccine injected into the muscle can be recognized by macrophages and antigen-presenting cells in the body, thus causing an immune response. So there is no need to worry. However, the recommended injection site for the new crown vaccine is still in the deltoid muscle because it is more convenient for injection, and it is adjacent to the axillary lymph nodes, which is conducive to the production of body immunity. In addition, there are fewer neurovascular vessels in this area, which can minimize the occurrence of vaccination complications.