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Lancet. 2020;395(10223):507-513. https:\/\/doi.org\/10.1016\/S0140-6736(20)30211-7","DOI":"10.1016\/S0140-6736(20)30211-7"},{"key":"ref4","doi-asserted-by":"publisher","unstructured":"Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497-506. https:\/\/doi.org\/10.1016\/S0140-6736(20)30183-5","DOI":"10.1016\/S0140-6736(20)30183-5"},{"key":"ref5","doi-asserted-by":"publisher","unstructured":"Hu B, Guo H, Zhou P, Shi Z-L. Characteristics of SARS-CoV-2 and COVID-19. Nat Rev Microbiol. 2020;19:141-154. https:\/\/doi.org\/10.1038\/s41579-020-00459-7","DOI":"10.1038\/s41579-020-00459-7"},{"key":"ref6","doi-asserted-by":"publisher","unstructured":"Chan JF-W, Yuan S, Kok K-H, et al. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: A study of a family cluster. 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Characteristics of peripheral lymphocyte subset alteration in COVID-19 Pneumonia. J Infect Dis. 2020;221(11):1762-1769. https:\/\/doi.org\/10.1093\/infdis\/jiaa150","DOI":"10.1093\/infdis\/jiaa150"},{"key":"ref10","doi-asserted-by":"publisher","unstructured":"Bai Y, Yao L, Wei T, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA. 2020;323(14):1406-1407. https:\/\/doi.org\/10.1001\/jama.2020.2565","DOI":"10.1001\/jama.2020.2565"},{"key":"ref11","doi-asserted-by":"publisher","unstructured":"Weiss SR, Leibowitz JL. Coronavirus pathogenesis. Adv Virus Res. 2011; 81:85-164. https:\/\/doi.org\/10.1016\/B978-0-12-385885-6.00009-2","DOI":"10.1016\/B978-0-12-385885-6.00009-2"},{"key":"ref12","unstructured":"Knipe DM, Howley PM. Fields virology: Editors-in-chief, David M. Knipe, Peter M. Howley. Philadelphia, PA: Wolters Kluwer\/Lippincott Williams & Wilkins Health; 2013."},{"key":"ref13","doi-asserted-by":"publisher","unstructured":"Su S, Wong G, Shi W, et al. 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The dynamics of humoral immune responses following SARS-CoV-2 infection and the potential for reinfection. J Gen Virol. 2020;101(8):791-797. https:\/\/doi.org\/10.1099\/jgv.0.001439","DOI":"10.1099\/jgv.0.001439"},{"key":"ref33","doi-asserted-by":"publisher","unstructured":"Wu L-P, Wang N-C, Chang Y-H, et al. Duration of antibody responses after severe acute respiratory syndrome. Emerg Infect Dis. 2007;13(10):1562-1564. https:\/\/doi.org\/10.3201\/eid1310.070576","DOI":"10.3201\/eid1310.070576"},{"key":"ref34","doi-asserted-by":"publisher","unstructured":"Xiao AT, Gao C, Zhang S. Profile of specific antibodies to SARS-CoV-2: The first report. J Infect. 2020;81(1):147-178. https:\/\/doi.org\/10.1016\/j.jinf.2020.03.012","DOI":"10.1016\/j.jinf.2020.03.012"},{"key":"ref35","doi-asserted-by":"publisher","unstructured":"Zeng H, Xu C, Fan J, et al. Antibodies in infants born to mothers with COVID-19 pneumonia. JAMA. 2020;323(18):1848-1849. https:\/\/doi.org\/10.1001\/jama.2020.4861","DOI":"10.1001\/jama.2020.4861"},{"key":"ref36","unstructured":"Africa CDC. Outbreak brief 86: Coronavirus disease 2019 (COVID-19) pandemic [homepage on the Internet]. Africa CDC"},{"key":"ref37","unstructured":"2021 [cited 2022 Sept 27]. Available from: https:\/\/africacdc.org\/download\/outbreak-brief-86-coronavirus-disease-2019-covid-19-pandemic\/"},{"key":"ref38","doi-asserted-by":"publisher","unstructured":"Embrett M, Sim SM, Caldwell HAT, et al. Barriers to and strategies to address COVID-19 testing hesitancy: A rapid scoping review. BMC Public Health. 2022;22(1):750. https:\/\/doi.org\/10.1186\/s12889-022-13127-7","DOI":"10.1186\/s12889-022-13127-7"},{"key":"ref39","unstructured":"Kaseje N. Why sub-Saharan Africa needs a unique response to COVID-19 [homepage on the Internet]. World Economic Forum; 2020 [cited 2021 Nov 24]. 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Burden and changes in HIV\/AIDS morbidity and mortality in Southern Africa development community countries, 1990-2017. BMC Public Health. 2020;20(1):867. https:\/\/doi.org\/10.1186\/s12889-020-08988-9","DOI":"10.1186\/s12889-020-08988-9"},{"key":"ref43","unstructured":"Dye C, Harries AD, Maher D, Hosseini SM, Nkhoma W, Salaniponi FM. Tuberculosis. In: Jamison DT, Feachem RG, Makgoba MW, et al., editors. Disease and mortality in sub-Saharan Africa [homepage on the Internet]. 2nd ed. Washington, DC: World Bank; 2006 [cited 2021 Nov 23]. Available from: http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK2285\/"},{"key":"ref44","doi-asserted-by":"publisher","unstructured":"Young F, Critchley JA, Johnstone LK, Unwin NC. A review of co-morbidity between infectious and chronic disease in sub Saharan Africa: TB and diabetes mellitus, HIV and metabolic syndrome, and the impact of globalization. Glob Health. 2009;5:9. https:\/\/doi.org\/10.1186\/1744-8603-5-9","DOI":"10.1186\/1744-8603-5-9"},{"key":"ref45","doi-asserted-by":"publisher","unstructured":"Corburn J, Hildebrand C. Slum sanitation and the social determinants of women's health in Nairobi, Kenya. J Environ Public Health. 2015;2015: e209505. https:\/\/doi.org\/10.1155\/2015\/209505","DOI":"10.1155\/2015\/209505"},{"key":"ref46","unstructured":"United Nations Human Settlements Programme (UN-Habitat). COVID-19 in African cities: Impacts, Responses and Policies 2020. Available from: https:\/\/unhabitat.org\/covid-19-in-africa-cities-impacts-responses-and-policies"},{"key":"ref47","unstructured":"UNICEF. Water, sanitation and hygiene [home on the Internet]. 2021 [cited 2021 Nov 23]. Available from: https:\/\/www.unicef.org\/wca\/what-we-do\/wash"},{"key":"ref48","doi-asserted-by":"publisher","unstructured":"Boutayeb A. The impact of infectious diseases on the development of Africa. In: Preedy VR, Watson RR, editors. Handbook of disease burdens and quality of life measures. New York, NY: Springer; 2010, pp. 1171-1188.","DOI":"10.1007\/978-0-387-78665-0_66"},{"key":"ref49","unstructured":"World Health Organization (WHO). Global health estimates: Leading causes of DALYs [Internet]. 2020 [cited 2022 Oct 31]. Available from: https:\/\/www.who.int\/data\/gho\/data\/themes\/mortality-and-global-health-estimates\/global-health-estimates-leading-causes-of-dalys"},{"key":"ref50","unstructured":"World Health Organization (WHO). World malaria report 2020 [homepage on the Internet]. 2020 [cited 2021 Sept 23]. Available from: https:\/\/www.who.int\/teams\/global-malaria-programme\/reports\/world-malaria-report-2020"},{"key":"ref51","doi-asserted-by":"publisher","unstructured":"Picker LJ, Watkins DI. HIV pathogenesis: The first cut is the deepest. Nat Immunol. 2005;6(5):430-432. https:\/\/doi.org\/10.1038\/ni0505-430","DOI":"10.1038\/ni0505-430"},{"key":"ref52","doi-asserted-by":"publisher","unstructured":"Naif HM. Pathogenesis of HIV infection. Infect Dis Rep. 2013;5(suppl. 1):e6. https:\/\/doi.org\/10.4081\/idr.2013.s1.e6","DOI":"10.4081\/idr.2013.s1.e6"},{"key":"ref53","unstructured":"UNAIDS. Global HIV & AIDS statistics - Fact sheet [home on the Internet]. 2020 [cited 2021 Sept 23]. Available from: https:\/\/www.unaids.org\/en\/resources\/fact-sheet"},{"key":"ref54","unstructured":"World Health Organization (WHO). Tuberculosis [homepage on the Internet]. 2018 [cited 2021 Nov 07]. Available from: https:\/\/www.who.int\/news-room\/q-a-detail\/tuberculosis"},{"key":"ref55","unstructured":"Toth A, Fackelmann J, Pigott W, Tolomeo O. Tuberculosis prevention and treatment. Can Nurse. 2004;100(9):27-30."},{"key":"ref56","unstructured":"World Health Organization (WHO). Global tuberculosis report 2020 [homepage on the Internet]. 2020 [cited 2021 Sept 23]. Available from: https:\/\/www.who.int\/publications\/i\/item\/9789240013131"},{"key":"ref57","unstructured":"World Health Organization (WHO). Ebola virus disease [home on the Internet]. 2021 [cited 2021 Sept 23]. Available from: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/ebola-virus-disease"},{"key":"ref58","doi-asserted-by":"publisher","unstructured":"Baseler L, Chertow DS, Johnson KM, Feldmann H, Morens DM. The pathogenesis of Ebola virus disease. Ann Rev Pathol. 2017;12:387-418. https:\/\/doi.org\/10.1146\/annurev-pathol-052016-100506","DOI":"10.1146\/annurev-pathol-052016-100506"},{"key":"ref59","unstructured":"World Health Organization (WHO). Ebola haemorrhagic fever in Zaire, 1976. Bull World Health Organ. 1978;56(2):271-293."},{"key":"ref60","doi-asserted-by":"publisher","unstructured":"Rouquet P, Froment J-M, Bermejo M, et al. Wild animal mortality monitoring and human Ebola outbreaks, Gabon and Republic of Congo, 2001-2003. Emerg Infect Dis. 2005;11(2):283-290. https:\/\/doi.org\/10.3201\/eid1102.040533","DOI":"10.3201\/eid1102.040533"},{"key":"ref61","unstructured":"CDC. 2014-2016 Ebola Outbreak in West Africa | History | Ebola (Ebola Virus Disease) | CDC [home on the Internet]. 2016 [cited 2021 Sept 23]. Available from: https:\/\/www.cdc.gov\/vhf\/ebola\/history\/2014-2016-outbreak\/index.html"},{"key":"ref62","doi-asserted-by":"publisher","unstructured":"Coltart CEM, Lindsey B, Ghinai I, Johnson AM, Heymann DL. The Ebola outbreak, 2013-2016: Old lessons for new epidemics. Philos Trans R Soc B Biol Sci. 2017;372(1721):20160297. https:\/\/doi.org\/10.1098\/rstb.2016.0297","DOI":"10.1098\/rstb.2016.0297"},{"key":"ref63","doi-asserted-by":"publisher","unstructured":"Rojek A, Horby P, Dunning J. Insights from clinical research completed during the West Africa Ebola virus disease epidemic. Lancet Infect Dis. 2017;17(9): e280-e292. https:\/\/doi.org\/10.1016\/S1473-3099(17)30234-7","DOI":"10.1016\/S1473-3099(17)30234-7"},{"key":"ref64","doi-asserted-by":"publisher","unstructured":"Iwasaki A, Medzhitov R. Control of adaptive immunity by the innate immune system. Nat Immunol. 2015;16(4):343-353. https:\/\/doi.org\/10.1038\/ni.3123","DOI":"10.1038\/ni.3123"},{"key":"ref65","doi-asserted-by":"publisher","unstructured":"Schenten D, Medzhitov R. The control of adaptive immune responses by the innate immune system. Adv Immunol. 2011;109:87-124. https:\/\/doi.org\/10.1016\/B978-0-12-387664-5.00003-0","DOI":"10.1016\/B978-0-12-387664-5.00003-0"},{"key":"ref66","unstructured":"Dianzani F, Baron S. Nonspecific defenses. In: Baron S, editor. Medical microbiology [homepage on the Internet]. 4th ed. Galveston, TX: University of Texas Medical Branch at Galveston; 1996 [cited 2021 Nov 21]. Available from: http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK8348\/"},{"key":"ref67","unstructured":"Klimpel GR. Immune defenses. In: Baron S, editor. Medical microbiology [homepage on the Internet]. 4th ed. Galveston, TX: University of Texas Medical Branch at Galveston; 1996 [cited 2021 Nov 21]. Available from: http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK8423\/"},{"key":"ref68","doi-asserted-by":"publisher","unstructured":"Netea MG, Dom\u00ednguez-Andr\u00e9s J, Barreiro LB, et al. Defining trained immunity and its role in health and disease. Nat Rev Immunol. 2020;20(6):375-388. https:\/\/doi.org\/10.1038\/s41577-020-0285-6","DOI":"10.1038\/s41577-020-0285-6"},{"key":"ref69","doi-asserted-by":"publisher","unstructured":"Netea MG, Quintin J, Van der Meer JWM. Trained immunity: A memory for innate host defense. 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Aging Dis. 2020;11(6):1339. https:\/\/doi.org\/10.14336\/AD.2020.1104","DOI":"10.14336\/AD.2020.1104"},{"key":"ref79","doi-asserted-by":"publisher","unstructured":"Gorse GJ, Patel GB, Vitale JN, O'Connor TZ. Prevalence of antibodies to four human coronaviruses is lower in nasal secretions than in serum. Clin Vaccine Immunol. 2010;17(12):1875-1880. https:\/\/doi.org\/10.1128\/CVI.00278-10","DOI":"10.1128\/CVI.00278-10"},{"key":"ref80","doi-asserted-by":"publisher","unstructured":"Lipsitch M, Grad YH, Sette A, Crotty S. Cross-reactive memory T cells and herd immunity to SARS-CoV-2. Nat Rev Immunol. 2020;20(11):709-713. https:\/\/doi.org\/10.1038\/s41577-020-00460-4","DOI":"10.1038\/s41577-020-00460-4"},{"key":"ref81","doi-asserted-by":"publisher","unstructured":"Le Bert N, Tan AT, Kunasegaran K, et al. SARS-CoV-2-specific T cell immunity in cases of COVID-19 and SARS, and uninfected controls. Nature. 2020;584(7821):457-462. https:\/\/doi.org\/10.1038\/s41586-020-2550-z","DOI":"10.1038\/s41586-020-2550-z"},{"key":"ref82","doi-asserted-by":"publisher","unstructured":"Stefano GB, Kream RM. Convalescent memory T cell immunity in individuals with mild or asymptomatic SARS-CoV-2 infection may result from an evolutionarily adapted immune response to coronavirus and the \"common cold.\" Int Med J Exp Clin Res. 2020;26: e929789. https:\/\/doi.org\/10.12659\/MSM.929789","DOI":"10.12659\/MSM.929789"},{"key":"ref83","doi-asserted-by":"publisher","unstructured":"Woldemeskel BA, Kwaa AK, Garliss CC, Laeyendecker O, Ray SC, Blankson JN. Healthy donor T cell responses to common cold coronaviruses and SARS-CoV-2. J Clin Invest. 2020;130(12):6631-6638. https:\/\/doi.org\/10.12659\/MSM.929789","DOI":"10.12659\/MSM.929789"},{"key":"ref84","doi-asserted-by":"publisher","unstructured":"Chakrabarti S, Chakrabarti SS, Kaur U, Agrawal BK, Ganguly U, Jin K. Cross-immunity and trained immunity in explaining variable COVID-19 mortality - Guidance for future pandemics. J Med Virol. 2021;93(7):4094-4096. https:\/\/doi.org\/10.1002\/jmv.26958","DOI":"10.1002\/jmv.26958"},{"key":"ref85","doi-asserted-by":"publisher","unstructured":"Zhao J, Zhao J, Mangalam AK, et al. Airway memory CD4(+) T cells mediate protective immunity against emerging respiratory coronaviruses. Immunity. 2016;44(6):1379-1391. https:\/\/doi.org\/10.1016\/j.immuni.2016.05.006","DOI":"10.1016\/j.immuni.2016.05.006"},{"key":"ref86","doi-asserted-by":"publisher","unstructured":"Pedersen J, Koumakpayi IH, Babuadze G, et al. Cross-reactive immunity against SARS-CoV-2 N protein in Central and West Africa precedes the COVID-19 pandemic. Sci Rep.;12(1):12962. https:\/\/doi.org\/10.1038\/s41598-022-17241-9","DOI":"10.1038\/s41598-022-17241-9"},{"key":"ref87","doi-asserted-by":"publisher","unstructured":"Tso FY, Lidenge SJ, Pe\u00f1a PB, et al. High prevalence of pre-existing serological cross-reactivity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in sub-Saharan Africa. Int J Infect Dis. 2021;102:577-583. https:\/\/doi.org\/10.1016\/j.ijid.2020.10.104","DOI":"10.1016\/j.ijid.2020.10.104"},{"key":"ref88","doi-asserted-by":"publisher","unstructured":"Emmerich P, Murawski C, Ehmen C, et al. Limited specificity of commercially available SARS-CoV-2 IgG ELISAs in serum samples of African origin. Trop Med Int Health. 2021;26(6):621-631. https:\/\/doi.org\/10.1111\/tmi.13569","DOI":"10.1111\/tmi.13569"},{"key":"ref89","doi-asserted-by":"publisher","unstructured":"Mveang Nzoghe A, Essone PN, Leboueny M, et al. Evidence and implications of pre-existing humoral cross-reactive immunity to SARS-CoV-2. Immun Inflamm Dis. 2021;9(1):128-133. https:\/\/doi.org\/10.1002\/iid3.367","DOI":"10.1002\/iid3.367"},{"key":"ref90","doi-asserted-by":"publisher","unstructured":"Yadouleton A, Sander AL, Moreira-Soto A, et al. Limited specificity of serologic tests for SARS-CoV-2 antibody detection, Benin. Emerg Infect Dis. 2021;27(1). https:\/\/doi.org\/10.3201\/eid2701.203281","DOI":"10.3201\/eid2701.203281"},{"key":"ref91","doi-asserted-by":"publisher","unstructured":"Grzelak L, Temmam S, Planchais C, et al. A comparison of four serological assays for detecting anti-SARS-CoV-2 antibodies in human serum samples from different populations. Sci Transl Med. 2020;12(559): eabc3103. https:\/\/doi.org\/10.1126\/scitranslmed.abc3103","DOI":"10.1126\/scitranslmed.abc3103"},{"key":"ref92","doi-asserted-by":"publisher","unstructured":"Ng KW, Faulkner N, Cornish GH, et al. Preexisting and de novo humoral immunity to SARS-CoV-2 in humans. Science. 2020;370(6522):1339-1343. https:\/\/doi.org\/10.1126\/science.abe1107","DOI":"10.1126\/science.abe1107"},{"key":"ref93","doi-asserted-by":"publisher","unstructured":"Song G, He W-T., Callaghan S, et al. Cross-reactive serum and memory B-cell responses to spike protein in SARS-CoV-2 and endemic coronavirus infection. Nat Commun. 2021;12(1):2938. https:\/\/doi.org\/10.1038\/s41467-021-23074-3","DOI":"10.1038\/s41467-021-23074-3"},{"key":"ref94","doi-asserted-by":"publisher","unstructured":"Netea MG, Joosten LAB, Latz E, et al. Trained immunity: A program of innate immune memory in health and disease. Science. 2016;352(6284): aaf1098. https:\/\/doi.org\/10.1126\/science.aaf1098","DOI":"10.1126\/science.aaf1098"},{"key":"ref95","doi-asserted-by":"publisher","unstructured":"Van't Wout JW, Poell R, Van Furth R. The role of BCG\/PPD-activated macrophages in resistance against systemic candidiasis in mice. Scand J Immunol. 1992;36(5):713-719. https:\/\/doi.org\/10.1111\/j.1365-3083.1992.tb03132.x","DOI":"10.1111\/j.1365-3083.1992.tb03132.x"},{"key":"ref96","doi-asserted-by":"publisher","unstructured":"Kaufmann E, Sanz J, Dunn JL, et al. BCG educates hematopoietic stem cells to generate protective innate immunity against tuberculosis. Cell. 2018;172(1-2):176-190.e19. https:\/\/doi.org\/10.1016\/j.cell.2017.12.031","DOI":"10.1016\/j.cell.2017.12.031"},{"key":"ref97","doi-asserted-by":"publisher","unstructured":"Arts RJW, Moorlag SJCFM, Novakovic B, et al. BCG vaccination protects against experimental viral infection in humans through the induction of cytokines associated with trained immunity. Cell Host Microbe. 2018;23(1):89-100.e5. https:\/\/doi.org\/10.1016\/j.chom.2017.12.010","DOI":"10.1016\/j.chom.2017.12.010"},{"key":"ref98","doi-asserted-by":"publisher","unstructured":"Walk J, De Bree LCJ, Graumans W, et al. Outcomes of controlled human malaria infection after BCG vaccination. Nat Commun. 2019;10(1):874. https:\/\/doi.org\/10.1038\/s41467-019-08659-3","DOI":"10.1038\/s41467-019-08659-3"},{"key":"ref99","doi-asserted-by":"publisher","unstructured":"Tanner R, Villarreal-Ramos B, Vordermeier HM, McShane H. The humoral immune response to BCG vaccination. Front Immunol. 2019;10:1317. https:\/\/doi.org\/10.3389\/fimmu.2019.01317","DOI":"10.3389\/fimmu.2019.01317"},{"key":"ref100","doi-asserted-by":"publisher","unstructured":"Moorlag SJCFM, Arts RJW, Van Crevel R, Netea MG. Non-specific effects of BCG vaccine on viral infections. Clin Microbiol Infect. 2019;25(12):1473-1478. https:\/\/doi.org\/10.1016\/j.cmi.2019.04.020","DOI":"10.1016\/j.cmi.2019.04.020"},{"key":"ref101","doi-asserted-by":"publisher","unstructured":"Arnoldussen DL, Linehan M, Sheikh A. BCG vaccination and allergy: A systematic review and meta-analysis. J Allergy Clin Immunol. 2011;127(1):246-53, 253.e1-e21. https:\/\/doi.org\/10.1016\/j.jaci.2010.07.039","DOI":"10.1016\/j.jaci.2010.07.039"},{"key":"ref102","doi-asserted-by":"publisher","unstructured":"Nakayama K, Monma M, Fukushima T, Ohrui T, Sasaki H. Tuberculin responses and risk of pneumonia in immobile elderly patients. Thorax. 2000;55(10):867-869. https:\/\/doi.org\/10.1136\/thorax.55.10.867","DOI":"10.1136\/thorax.55.10.867"},{"key":"ref103","doi-asserted-by":"publisher","unstructured":"Ohrui T, Nakayama K, Fukushima T, Chiba H, Sasaki H. [Prevention of elderly pneumonia by pneumococcal, influenza and BCG vaccinations]. Nihon Ronen Igakkai Zasshi Jpn J Geriatr. 2005;42(1):34-36. https:\/\/doi.org\/10.3143\/geriatrics.42.34","DOI":"10.3143\/geriatrics.42.34"},{"key":"ref104","doi-asserted-by":"publisher","unstructured":"Giamarellos-Bourboulis EJ, Tsilika M, Moorlag S, et al. Activate: Randomized clinical trial of BCG vaccination against infection in the elderly. Cell. 2020;183(2):315-323.e9. https:\/\/doi.org\/10.1016\/j.cell.2020.08.051","DOI":"10.1016\/j.cell.2020.08.051"},{"key":"ref105","doi-asserted-by":"publisher","unstructured":"Nguipdop-Djomo P, Heldal E, Rodrigues LC, Abubakar I, Mangtani P. Duration of BCG protection against tuberculosis and change in effectiveness with time since vaccination in Norway: A retrospective population-based cohort study. Lancet Infect Dis. 2016;16(2):219-226. https:\/\/doi.org\/10.1016\/S1473-3099(15)00400-4","DOI":"10.1016\/S1473-3099(15)00400-4"},{"key":"ref106","doi-asserted-by":"publisher","unstructured":"Aronson NE, Santosham M, Comstock GW, et al. Long-term efficacy of BCG vaccine in American Indians and Alaska Natives: A 60-year follow-up study. JAMA. 2004;291(17):2086-2091. https:\/\/doi.org\/10.1001\/jama.291.17.2086","DOI":"10.1001\/jama.291.17.2086"},{"key":"ref107","doi-asserted-by":"publisher","unstructured":"Menzies D. Interpretation of repeated tuberculin tests. Boosting, conversion, and reversion. Am J Respir Crit Care Med. 1999;159(1):15-21. https:\/\/doi.org\/10.1164\/ajrccm.159.1.9801120","DOI":"10.1164\/ajrccm.159.1.9801120"},{"key":"ref108","doi-asserted-by":"publisher","unstructured":"Miller A, Reandelar MJ, Fasciglione K, Roumenova V, Li Y, Otazu GH. Correlation between universal BCG vaccination policy and reduced morbidity and mortality for COVID-19: An epidemiological study [serial online]. 2020 [cited 2021 Nov 16]:20042937. Available from: https:\/\/www.medrxiv.org\/content\/10.1101\/2020.03.24.20042937v1","DOI":"10.1101\/2020.03.24.20042937"},{"key":"ref109","doi-asserted-by":"publisher","unstructured":"Levine DI. A shred of evidence that BCG vaccine may protect against COVID-19: Comparing cohorts in Spain and Italy [serial online]. 2020 [cited 2021 Nov 17]:20123539. Available from: https:\/\/www.medrxiv.org\/content\/10.1101\/2020.06.05.20123539v1","DOI":"10.1101\/2020.06.05.20123539"},{"key":"ref110","doi-asserted-by":"publisher","unstructured":"Curtis N, Sparrow A, Ghebreyesus TA, Netea MG. Considering BCG vaccination to reduce the impact of COVID-19. Lancet. 2020;395(10236):1545-1546. https:\/\/doi.org\/10.1016\/S0140-6736(20)31025-4","DOI":"10.1016\/S0140-6736(20)31025-4"},{"key":"ref111","doi-asserted-by":"publisher","unstructured":"Brooks NA, Puri A, Garg S, et al. The association of coronavirus disease-19 mortality and prior bacille Calmette-Guerin vaccination: A robust ecological analysis using unsupervised machine learning. Sci Rep. 2021;11(1):774. https:\/\/doi.org\/10.1038\/s41598-020-80787-z","DOI":"10.1038\/s41598-020-80787-z"},{"key":"ref112","doi-asserted-by":"publisher","unstructured":"Hensel J, McAndrews KM, McGrail DJ, Dowlatshahi DP, LeBleu VS, Kalluri R. Protection against SARS-CoV-2 by BCG vaccination is not supported by epidemiological analyses. Sci Rep. 2020;10(1):18377. https:\/\/doi.org\/10.1038\/s41598-020-75491-x","DOI":"10.1038\/s41598-020-75491-x"},{"key":"ref113","doi-asserted-by":"publisher","unstructured":"Seeley JJ, Ghosh S. Molecular mechanisms of innate memory and tolerance to LPS. J Leukoc Biol. 2017;101(1):107-119. https:\/\/doi.org\/10.1189\/jlb.3MR0316-118RR","DOI":"10.1189\/jlb.3MR0316-118RR"},{"key":"ref114","unstructured":"World Health Organization (WHO). Tracking SARS-CoV-2 variants [homepage on the Internet]. 2021 [cited 2021 Dec 25]. Available from: https:\/\/www.who.int\/en\/activities\/tracking-SARS-CoV-2-variants\/"},{"key":"ref115","doi-asserted-by":"publisher","unstructured":"Parums DV. Revised World Health Organization (WHO) terminology for variants of concern and variants of interest of SARS-CoV-2. Med Sci Monit. 2021;27: e933622. https:\/\/doi.org\/10.12659\/MSM.933622","DOI":"10.12659\/MSM.933622"},{"key":"ref116","doi-asserted-by":"publisher","unstructured":"Zahradn\u00edk J, Marciano S, Shemesh M, et al. SARS-CoV-2 variant prediction and antiviral drug design are enabled by RBD in vitro evolution. Nat Microbiol. 2021;6:1188-1198. https:\/\/doi.org\/10.1038\/s41564-021-00954-4","DOI":"10.1038\/s41564-021-00954-4"},{"key":"ref117","doi-asserted-by":"publisher","unstructured":"Ren SY, Wang WB, Gao RD, Zhou AM. Omicron variant (B.1.1.529) of SARS-CoV-2: Mutation, infectivity, transmission, and vaccine resistance. World J Clin Cases. 2022;10(1):1-11. https:\/\/doi.org\/10.12998\/wjcc.v10.i1.1","DOI":"10.12998\/wjcc.v10.i1.1"},{"key":"ref118","unstructured":"HKU Med. HKUMed finds Omicron SARS-CoV-2 can infect faster and better than Delta in human bronchus but with less severe infection in lung. Hong Kong: HKU Med."},{"key":"ref119","doi-asserted-by":"publisher","unstructured":"Callaway E. Omicron likely to weaken COVID vaccine protection. Nature. 2021;600:367-368. https:\/\/doi.org\/10.1038\/d41586-021-03672-3","DOI":"10.1038\/d41586-021-03672-3"},{"key":"ref120","doi-asserted-by":"publisher","unstructured":"Callaway E, Ledford H. How bad is Omicron? Nature. 2021;600:197-199. https:\/\/doi.org\/10.1038\/d41586-021-03614-z","DOI":"10.1038\/d41586-021-03614-z"},{"key":"ref121","unstructured":"Pfizer Inc. Pfizer and BioNTech provide update on Omicron variant [homepage on the Internet]. 2021 [cited 2021 Dec 09]. Available from: https:\/\/www.businesswire.com\/news\/home\/20211208005542\/en\/Pfizer-and-BioNTech-Provide-Update-on-Omicron-Variant"},{"key":"ref122","unstructured":"Wilhelm A, Widera M, Grikscheit K, et al. Reduced neutralization of SARS-CoV-2 Omicron variant by vaccine sera and monoclonal antibodies [homepage on the Internet]. 2021, p. 21267432 [cited 2021 Dec 09]. 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