Abstract: Background：Coronavirus Disease 2019 (COVID19) vaccination plays an important role in controlling the pandemic and protecting population from developing into a severe type. The vaccination safety in children with a history of allergy has been a common concern. Objective：To provide the best immunization practice and recommendations for children with a history of allergy. Design：Case series report. Methods：Children and adolescents aged 3 to 17 who were consulted at the designated pediatric COVID19 vaccine advisory clinic in Children's Hospital of Fudan University between August 12nd, 2021 and December 3rd, 2021 were included. Based on individual's past medical history, current health status, and parental concerns, individualized assessments are made, and recommendations for deferring and recommending vaccinations are given. Telephone followup was conducted to collect adverse events following immunization (AEFI) within 72 h and 28 d after vaccination and any unsolicited adverse events reported by parents. The causal association between AEFI and vaccine was assessed. Main outcome measures：AEFI of COVID19 vaccine. Results：A total of 116 children consulted for COVID19 vaccination, including 67 boys (57.8%) and 49 girls, aged (10.1±3.1) years old. Seventyseven (66.4%) were recommended to start vaccination, and 39 were recommended to defer vaccination after individualized assessment in the immunization advisory clinic. The followings were recommended to defer the vaccination 25 cases in the acute phase of allergic disease among 70 cases (60.3%) with a history of allergy, 5 cases of severe allergic reactions among 11 cases (9.5%) with a history of other vaccine or drug allergy, 5 cases in the acute phase of the disease in 13 cases (11.2%) with a history of nondrug allergy, and 3 cases of acute illness (respiratory tract infection) among 21 cases (18.1%) with atopy, and 1 case（0.9%）with a history of allergic to the first dose of COVID19 vaccine. All patients in the deferring vaccination group completed the telephone followup 3 months after the consultation. Seventyseven children in the recommended starting vaccination group were followed up for 3 times, among which 54 cases were in the vaccinated subgroup (47 children receiving 2 doses of vaccine, 7 children receiving 1 dose of vaccine), and 23 cases were in the unvaccinated subgroup. There were no significant differences in gender, allergic disease history, other vaccine or drug allergy history, nondrug allergy history and atopy between the two subgroups. The age ［(10.4±3.0) years vs (9.0±3.1) years old, P=0.04］ between the two subgroups had statistically significant difference. No severe allergic reactions were collected during the telephone followup at 4 d and 28 d after vaccination. Within 72 hours after vaccination, 18 cases (17.8%) were solicited with 10 systemic adverse events, 5 cases (5.0%) of rash and cough respectfully, 4 cases (4.0%) of runny nose, 3 cases (3.0%) of anorexia and fever respectfully, 2 cases (2.0%) of sore throat, 1 case (1.0%) of fatigue, myalgia, nausea and vomiting respectively. There was a causal relationship with the AEFIs and COVID19 vaccine after preliminary judgement. No additional solicited adverse reactions were reported in the 28 d and 3month telephone followup. Within 28 days after vaccination, parents voluntarily reported 5 cases of unsolicited adverse events, 3 cases (3.0%) of idiopathic dermatitis or eczema, and 2 cases (2.0%) of allergic rhinitis. No causal relationship with COVID19 vaccine was found. The incidence of AEFIs of COVID19 vaccine within 28 days was 33.3% (18/54). Conclusion：It is safe for children whose allergic diseases are in remission status, those who had nonsevere allergic reactions to nonCOVID19 vaccines or other drugs, those who had nondrug allergy history, and those who had atopy to receive inactivated COVID19 vaccines. The systemic adverse reactions of AEFIs of COVID19 vaccine all occurred within 72 hours after vaccination, and were causally related to the COVID19 vaccination.

Key words: SARS-COV-2, Vaccine, Allergy history, Children, Safety, allergy, Adverse events following immunization