Abstract: Objective To investigate the clinical characteristics of SARS-CoV-2 delta variant in children and the similarities and differences between children and adults.Methods The clinical data of 54 children infected with SARS-COV-2 delta variant in Yangzhou were retrospectively analyzed and were compared with those of adults who were diagnosed in the same period.Results There were 35 boys and 19 girls in the children group and the mean age was (8.1±3.4) years. In the adult group, there were 37 patients (23 boys and 14 girls), and the mean age was (33.4±7.6) years. Compared with the adult group, the children group had a higher proportion of mild cases, a lower proportion of vaccination, a lower proportion of respiratory symptoms, a higher level of CK-MB, a lower level of CRP and IL-6, and a lower titer of SARS-CoV-2 IgG and IgM antibodies on admission, and the differences were statistically significant (P<0.05). No antibiotics or glucocorticoids were given in 2 groups. The patients were mainly treated with traditional Chinese medicine, posture therapy and symptomatic treatment, and the prognosis were good. The time from onset to disappearance of clinical symptoms was 4.0 (2.0-7.0) days in the children group and 7.0 (4.2-10.8) days in the adult group, and the difference between the two groups was statistically significant (P<0.01). The peak values of SARS-CoV-2 IgG and IgM antibodies in the children group were lower than those in the adult group, and the differences were statistically significant (P<0.05).Conclusions Children are also susceptible to the SARS-COV-2 delta variant, with a higher proportion of mild infection. Furthermore, children are more likely to have myocardial injury and recover faster than adults.

Key words: SARS-CoV-2, delta variant, clinical feature, child