Introduction
Omicron is a variant of the novel coronavirus. Compared with other strains, Omicron is highly transmissible and highly occult. After infection, it mainly presents systemic symptoms such as fever and is mostly accompanied by local symptoms such as respiratory symptoms such as cough, digestive symptoms such as vomiting, and nervous system symptoms such as dizziness1,2. Up to 30% of COVID-19 infections in adults have neurological symptoms, such as memory loss, confusion, severe headaches, and even stroke, which can persist even after the infection has ended, while children who are infected have a lower incidence of neurological symptoms, but are more likely to experience coughing, wheezing, and wheezing. In addition to the inflammation of the lung interstitial after COVID-19 infection, it may also be related to the regulation of the expression of neuropeptides in lung epithelial cells2-4. There are abundant neuropeptide systems in the human body, such as the neurokinin family (Substance P, SP) and the bombine peptide family: Bell toad peptide, gastrin-releasing peptide (GRP), neurokinin B, vasoactive intestinal peptide, ACE/ACE2, such as vasoactive intestinal peptide (VIP), neuroblast-specific transfer factor (Achaete scute homolog 1 (ASCL1), and angiotensinase. ACE2 has been shown to be the key for the new coronavirus to enter the human body. In 2022, Professor Rick Thompson of Queensland University of Technology said that the new coronavirus needs to bind to the receptor ACE2 on the surface of human cells to enter and infect human cell C, and their research found that even if it is only briefly exposed to atmospheric pressure cold plasma. The ACE2 receptor on the cell surface will also disappear immediately, which reduces the way for the novel coronavirus to infect human cells through the receptor and achieve the effect of preventing infection 5,6. The expression of other neuropeptide family members in children with COVID-19 infection and their correlation with inflammatory indicators will be further discussed below.