| 1. | Schreiber M. The scientist in Botswana who identified omicron was saddened by the world's reaction. NPR. https://tinyurl.com/at2c6u3n. Accessed on 2022-01-25. | 
				                                                        
				                                                            
				                                                                | 2. | World Health Organization Classification of Omicron (B.1.1.529): SARS-CoV-2 variant of concern. https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-con. Accessed on 2021-11-26. | 
				                                                        
				                                                            
				                                                                | 3. | Torjesen I. Covid-19: Omicron may be more transmissible than other variants and partly resistant to existing vaccines, scientists fear. BMJ, 2021, 375: n2943. | 
				                                                        
				                                                            
				                                                                | 4. | Desingu PA, Nagarajan K, Dhama K. Emergence of Omicron third lineage BA. 3 and its importance. J Med Virol, 2022, 94(5): 1808-1810. | 
				                                                        
				                                                            
				                                                                | 5. | Majumdar S, Sarkar R. Mutational and phylogenetic analyses of the two lineages of the Omicron variant. J Med Virol, 2022, 94(5): 1777-1779. | 
				                                                        
				                                                            
				                                                                | 6. | Qu P, Evans JP, Faraone J, et al. Distinct neutralizing antibody escape of SARS-CoV-2 Omicron subvariants BQ. 1, BQ. 1.1, BA. 4.6, BF. 7 and BA. 2.75. 2. bioRxiv, 2022, 2022.10. 19.512891. | 
				                                                        
				                                                            
				                                                                | 7. | Cao Y, Yisimayi A, Jian F, et al. BA. 2. 12. 1, BA. 4 and BA. 5 escape antibodies elicited by Omicron infection. Nature, 2022, 608(7923): 593-602. | 
				                                                        
				                                                            
				                                                                | 8. | Zhang X, Zhang W, Chen S. Shanghai's life-saving efforts against the current omicron wave of the COVID-19 pandemic. Lancet, 2022, 399(10340): 2011-2012. | 
				                                                        
				                                                            
				                                                                | 9. | 中華人民共和國國家衛生健康委員會. 新型冠狀病毒肺炎診療方案(試行第九版). 中華臨床感染病雜志, 2022, 15(2): 81-89. | 
				                                                        
				                                                            
				                                                                | 10. | Gómez-Ochoa SA, Franco OH, Rojas LZ, et al. COVID-19 in health-care workers: A living systematic review and meta-analysis of prevalence, risk factors, clinical characteristics, and outcomes. Am J Epidemiol, 2021, 190(1): 161-175. | 
				                                                        
				                                                            
				                                                                | 11. | Li J, Huang DQ, Zou B, et al. Epidemiology of COVID-19: A systematic review and meta-analysis of clinical characteristics, risk factors, and outcomes. J Med Virol, 2021, 93(3): 1449-1458. | 
				                                                        
				                                                            
				                                                                | 12. | Chen J, Wang R, Gilby NB, et al. Omicron variant (B. 1.1. 529): Infectivity, vaccine breakthrough, and antibody resistance. J Chem Inf Model, 2022, 62(2): 412-422. | 
				                                                        
				                                                            
				                                                                | 13. | Wolter N, Jassat W, Walaza S, et al. Early assessment of the clinical severity of the SARS-CoV-2 omicron variant in South Africa: A data linkage study. Lancet, 2022, 399(10323): 437-446. | 
				                                                        
				                                                            
				                                                                | 14. | Maslo C, Friedland R, Toubkin M, et al. Characteristics and outcomes of hospitalized patients in South Africa during the COVID-19 Omicron wave compared with previous waves. JAMA, 2022, 327(6): 583-584. | 
				                                                        
				                                                            
				                                                                | 15. | UKHSA. SARS-CoV-2 variants of concern and variants under investigation in England: Technical briefing 31, 2021. https://www.gov.uk/government/publications/investigation-of-sars-cov-2-variants-technical-briefings. | 
				                                                        
				                                                            
				                                                                | 16. | Torjesen I. Covid-19: Omicron variant is linked to steep rise in hospital admissions of very young children. BMJ, 2022, 376: o110. | 
				                                                        
				                                                            
				                                                                | 17. | Bhattacharyya RP, Hanage WP. Challenges in inferring intrinsic severity of the SARS-CoV-2 Omicron variant. N Engl J Med, 2022, 386(7): e14. | 
				                                                        
				                                                            
				                                                                | 18. | Elliott J, Bodinier B, Whitaker M, et al. COVID-19 mortality in the UK biobank cohort: Revisiting and evaluating risk factors. Eur J Epidemiol, 2021, 36(3): 299-309. | 
				                                                        
				                                                            
				                                                                | 19. | Singh AK, Gillies CL, Singh R, et al. Prevalence of co-morbidities and their association with mortality in patients with COVID-19: A systematic review and meta-analysis. Diabetes Obes Metab, 2020, 22(10): 1915-1924. | 
				                                                        
				                                                            
				                                                                | 20. | Singh AK, Khunti K. COVID-19 and diabetes. Annu Rev Med, 2022, 73: 129-147. | 
				                                                        
				                                                            
				                                                                | 21. | Kang YJ. South Korea's COVID-19 infection status: From the perspective of re-positive test results after viral clearance evidenced by negative test results. Disaster Med Public Health Prep, 2020, 14(6): 762-764. | 
				                                                        
				                                                            
				                                                                | 22. | Zou Y, Wang BR, Sun L, et al. The issue of recurrently positive patients who recovered from COVID-19 according to the current discharge criteria: Investigation of patients from multiple medical institutions in Wuhan, China. J Infect Dis, 2020, 222(11): 1784-1788. | 
				                                                        
				                                                            
				                                                                | 23. | Zou L, Ruan F, Huang M, et al. SARS-CoV-2 viral load in upper respiratory specimens of infected patients. N Engl J Med, 2020, 382(12): 1177-1179. | 
				                                                        
				                                                            
				                                                                | 24. | Spitzer A, Angel Y, Marudi O, et al. Association of a third dose of BNT162b2 vaccine with incidence of SARS-CoV-2 infection among health care workers in Israel. JAMA, 2022, 327(4): 341-349. | 
				                                                        
				                                                            
				                                                                | 25. | Fleming-Dutra KE, Britton A, Shang N, et al. Association of prior BNT162b2 COVID-19 vaccination with symptomatic SARS-CoV-2 infection in children and adolescents during omicron predominance. JAMA, 2022, 327(22): 2210-2219. | 
				                                                        
				                                                            
				                                                                | 26. | Hong Kong Centre for Health Protection of the Department of Health, and the Hospital Authority. Statistics on 5th wave of COVID-19. Sep 20, 2022. https://www.covidvaccine.gov. hk/pdf/5th_wave_statistics.pdf. Accessed on 2022-9-20. | 
				                                                        
				                                                            
				                                                                | 27. | 徐湘茹, 孫鼎, 曹敏, 等. 上海市4?264例無癥狀及輕型新冠病毒感染者臨床特征及預后轉歸分析. 中華危重病急救醫學, 2022, 34(5): 449-453. |