Abstract: Background：After the adjustment of COVID-19 prevention and control measures in China, there is insufficient data to prove the relationship between asthma in children and COVID-19 infection. Objective：To analyze whether COVID-19 infection affects the control and treatment of asthma in children. Design：A cross-sectional study. Methods：From March 10th to 31rd in 2023, children were enrolled from the outpatient departments of respiratory, asthma, desensitization and anti-IgE at Guangzhou Women and Children's Medical Center during the first month after the new COVID-19 epidemic prevention policy was launched. The modified COVID-19 Post-infection questionnaire (Modified Questionnaire) for allergic rhinitis and asthma children was used.The children who had COVID-19 infection from November 16th, 2022 to March 16th, 2023 and had previously diagnosis of asthma were taken as the asthma group, including four subgroups of dust mite allergic immunotherapy(AIT)+ omalizumab, dust mite AIT, regular inhaled corticosteroids（ICS）and on-demand medication for different interventions. Children who had no history of asthma were taken as the non-asthma group. Main outcome measures：Hospitalization proportion by COVID-19 infection for children with asthma. Results：In total, 317 children who were infected by COVID-19 from November 16th, 2022 to March 16th, 2023 and voluntarily participated in the Modified Questionnaire investigation were enrolled from March 1, 2023 to March 31, 2023. There were 200 cases (63.1%) in the non-asthma group and 117 cases in the asthma group. Of the asthma group, there were 10 cases in dust mite AIT+omalizumab subgroup, 25 cases in dust mite AIT subgroup, 29 cases in ICS subgroup, and 53 cases in on-demand medication subgroup. There was no significant difference in baseline data of gender, age, height, and weight. There were significant differences in diagnosis and comorbidities between the non-asthma group and the asthma group (P<0.05). The proportion of respiratory tract infection in the non-asthma group was higher than that in the asthma group, and the proportion of allergic rhinitis, food allergy, and atopic dermatitis in the asthma group was higher than that in the non-asthma group(P<0.05). The COVID-19 vaccine coverage rate and the second dose of vaccine coverage rate in the asthma group were significantly higher than those in the non-asthma group (P< 0.05).The proportion of asymptomatic infection in the asthma group was higher than that in the non-asthma group, with statistically significant difference (P<0.05). The proportion of fever，peak body temperature，cough and phlegm and vomiting in the non-asthma group was higher than that in the asthma group. The difference was statistically significant (P<0.05). There was no significant difference in hospitalization for COVID-19 infection between the two groups. For remission and acute stages of asthma, there was no statistically significant difference(P> 0.05) between four subgroups in the asthma group before and after COVID-19 infection in terms of the assessment of ACTTM and VAS in the remission period and the assessment of dyspnea, night waking or early waking, and the need to use emergency medication (such as ventorin) in the acute stage. Conclusions：Compared with non-asthma children, children with asthma had higher rate of asymptomatic COVID-19 infection, and milder clinical symptoms of COVID-19 infection. The use of AIT and/or anti-IgE therapy has no impact on the severity of disease in children with asthma when they are infected with COVID-19.

Key words: Asthma, Children, COVID-19