[1] Peacock TP, Penrice-Randal R, Hiscox JA, Barclay WS. SARS-CoV-2 one year on: evidence for ongoing viral adaptation. J Gen Virol 2021;102(4):001584. http://dx.doi.org/10.1099/jgv.0.001584CrossRef
[2] Chavda VP, Patel AB, Vaghasiya DD. SARS-CoV-2 variants and vulnerability at the global level. J Med Virol 2022;94(7):2986 − 3005. http://dx.doi.org/10.1002/jmv.27717CrossRef
[3] Tao KM, Tzou PL, Nouhin J, Gupta RK, de Oliveira T, Pond SLK, et al. The biological and clinical significance of emerging SARS-CoV-2 variants. Nat Rev Genet 2021;22(12):757 − 73. http://dx.doi.org/10.1038/s41576-021-00408-xCrossRef
[4] World Health Organization. Tracking SARS-CoV-2 variants. 2022. https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/. [2022-8-2].https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/
[5] Ma HL, Zhang JQ, Wang J, Qin Y, Chen C, Song Y, et al. COVID-19 outbreak caused by contaminated packaging of imported cold-chain products — Liaoning Province, China, July 2020. China CDC Wkly 2021;3(21):441 − 7. http://dx.doi.org/10.46234/ccdcw2021.114CrossRef
[6] Ma HL, Wang ZG, Zhao X, Han J, Zhang Y, Wang H, et al. Long distance transmission of SARS-CoV-2 from contaminated cold chain products to humans — Qingdao City, Shandong Province, China, September 2020. China CDC Wkly 2021;3(30):637 − 44. http://dx.doi.org/10.46234/ccdcw2021.164CrossRef
[7] Chen C, Feng YN, Chen ZX, Xia Y, Zhao X, Wang J, et al. SARS-CoV-2 cold-chain transmission: characteristics, risks, and strategies. J Med Virol 2022;94(8):3540 − 7. http://dx.doi.org/10.1002/jmv.27750CrossRef
[8] Zhou L, Nie K, Zhao HT, Zhao X, Ye BX, Wang J, et al. Eleven COVID-19 outbreaks with local transmissions caused by the imported SARS-CoV-2 delta VOC — China, July–August, 2021. China CDC Wkly 2021;3(41):863 − 8. http://dx.doi.org/10.46234/ccdcw2021.213CrossRef
[9] Cheng C, Wang L, Lyu ZQ, Peng B, Li YH, Kong DF, et al. Four COVID-19 cases of new variant B.1.351 first emerging in South Africa in Chinese passengers on same flight — Shenzhen, China, January 2021. China CDC Wkly 2021;3(8):175 − 7. http://dx.doi.org/10.46234/ccdcw2021.049.http://dx.doi.org/10.46234/ccdcw2021.049
[10] O'Toole Á, Scher E, Underwood A, Jackson B, Hill V, McCrone JT, et al. Assignment of epidemiological lineages in an emerging pandemic using the pangolin tool. Virus Evol 2021;7(2):veab064. http://dx.doi.org/10.1093/ve/veab064CrossRef
[11] Civil Aviation Administration of China. 2021 statistical bulletin of civil airport development in China. 2022. http://www.caac.gov.cn/XXGK/XXGK/TJSJ/202203/t20220322_212478.html. [2022-8-2]. (In Chinese). http://www.caac.gov.cn/XXGK/XXGK/TJSJ/202203/t20220322_212478.html
[12] World Health Organization. Genomic sequencing of SARS-CoV-2: a guide to implementation for maximum impact on public health. 2021. https://www.who.int/publications/i/item/9789240018440. [2022-8-2].https://www.who.int/publications/i/item/9789240018440
[13] GISAID. hCoV-19 submission tracker. 2022. https://gisaid.org/submission-tracker-global/. [2022-8-2].https://gisaid.org/submission-tracker-global/
[14] GISAID. Tracking of variants. 2022. https://www.gisaid.org/hcov19-variants/. [2022-8-2].https://www.gisaid.org/hcov19-variants/
[15] Rego N, Costábile A, Paz M, Salazar C, Perbolianachis P, Spangenberg L, et al. Real-time genomic surveillance for SARS-CoV-2 variants of concern, Uruguay. Emerg Infect Dis 2021;27(11):2957 − 60. http://dx.doi.org/10.3201/EID2711.211198CrossRef
[16] Paul P, France AM, Aoki Y, Batra D, Biggerstaff M, Dugan V, et al. Genomic surveillance for SARS-CoV-2 variants circulating in the United States, December 2020-May 2021. MMWR Morb Mortal Wkly Rep 2021;70(23):846 − 50. http://dx.doi.org/10.15585/mmwr.mm7023a3CrossRef
[17] World Health Organization. Weekly epidemiological update on COVID-19 - 11 May 2022. 2022. https://www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-19---11-may-2022. [2022-8-2].https://www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-19---11-may-2022