BCG vaccination to reduce the impact of COVID-19 in healthcare workers: Protocol for a randomised controlled trial (BRACE trial)

Laure F Pittet, Nicole L Messina, Kaya Gardiner, Francesca Orsini, Veronica Abruzzo, Samantha Bannister, Marc Bonten, John L Campbell, Julio Croda, Margareth Dalcolmo, Sonja Elia, Susie Germano, Casey Goodall, Amanda Gwee, Tenaya Jamieson, Bruno Jardim, Tobias R Kollmann, Marcus Vinícius Guimarães Lacerda, Katherine J Lee, Donna Legge, Michaela Lucas, David J Lynn, Ellie McDonald, Laurens Manning, Craig F Munns, Kirsten P Perrett, Cristina Prat Aymerich, Peter Richmond, Frank Shann, Eva Sudbury, Paola Villanueva, Nicholas J Wood, Katherine Lieschke, Kanta Subbarao, Andrew Davidson, Nigel Curtis, BRACE trial Consortium Group

Abstract

Introduction: BCG vaccination modulates immune responses to unrelated pathogens. This off-target effect could reduce the impact of emerging pathogens. As a readily available, inexpensive intervention that has a well-established safety profile, BCG is a good candidate for protecting healthcare workers (HCWs) and other vulnerable groups against COVID-19.

Methods and analysis: This international multicentre phase III randomised controlled trial aims to determine if BCG vaccination reduces the incidence of symptomatic and severe COVID-19 at 6 months (co-primary outcomes) compared with no BCG vaccination. We plan to randomise 10 078 HCWs from Australia, The Netherlands, Spain, the UK and Brazil in a 1:1 ratio to BCG vaccination or no BCG (control group). The participants will be followed for 1 year with questionnaires and collection of blood samples. For any episode of illness, clinical details will be collected daily, and the participant will be tested for SARS-CoV-2 infection. The secondary objectives are to determine if BCG vaccination reduces the rate, incidence, and severity of any febrile or respiratory illness (including SARS-CoV-2), as well as work absenteeism. The safety of BCG vaccination in HCWs will also be evaluated. Immunological analyses will assess changes in the immune system following vaccination, and identify factors associated with susceptibility to or protection against SARS-CoV-2 and other infections.

Ethics and dissemination: Ethical and governance approval will be obtained from participating sites. Results will be published in peer-reviewed open-access journals. The final cleaned and locked database will be deposited in a data sharing repository archiving system.

Trial registration: ClinicalTrials.gov NCT04327206.

Keywords: COVID-19; immunology; infectious diseases; microbiology; virology.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.

Figures

Figure 1
Figure 1
Study flow chart.

References

    1. World Health Organisation . Report of the WHO-China joint mission on coronavirus disease 2019 (COVID-19). World Health Organisation, 2020: 40.
    1. Anderson RM, Heesterbeek H, Klinkenberg D, et al. . How will country-based mitigation measures influence the course of the COVID-19 epidemic? Lancet 2020;395:931–4. 10.1016/S0140-6736(20)30567-5
    1. 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;190:161–75. 10.1093/aje/kwaa191
    1. Chou R, Dana T, Buckley DI, et al. . Epidemiology of and risk factors for coronavirus infection in health care workers. Ann Intern Med 2020;173:120–36. 10.7326/M20-1632
    1. Nguyen LH, Drew DA, Graham MS, et al. . Risk of COVID-19 among front-line health-care workers and the general community: a prospective cohort study. Lancet Public Health 2020;5:e475–83. 10.1016/S2468-2667(20)30164-X
    1. Amesty International . Global: amnesty analysis reveals over 7,000 health workers have died from COVID-19, 2020. Available: [Accessed 24 Sep 2020].
    1. Pollard AJ, Finn A, Curtis N. Non-specific effects of vaccines: plausible and potentially important, but implications uncertain. Arch Dis Child 2017;102:1077–81. 10.1136/archdischild-2015-310282
    1. Hollm-Delgado M-G, Stuart EA, Black RE. Acute lower respiratory infection among Bacille Calmette-Guérin (BCG)-vaccinated children. Pediatrics 2014;133:e73–81. 10.1542/peds.2013-2218
    1. de Castro MJ, Pardo-Seco J, Martinón-Torres F. Nonspecific (heterologous) protection of neonatal BCG vaccination against hospitalization due to respiratory infection and sepsis. Clin Infect Dis 2015;60:1611–9. 10.1093/cid/civ144
    1. 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;23:89–100. 10.1016/j.chom.2017.12.010
    1. Nemes E, Geldenhuys H, Rozot V, et al. . Prevention of M. tuberculosis Infection with H4:IC31 Vaccine or BCG Revaccination. N Engl J Med 2018;379:138–49. 10.1056/NEJMoa1714021
    1. Wardhana D, Datau EA, Sultana A. The efficacy of Bacillus Calmette-Guerin vaccinations for the prevention of acute upper respiratory tract infection in the elderly. Acta Med Indones 2011;43:185–90.
    1. Giamarellos-Bourboulis EJ, Tsilika M, Moorlag S, et al. . Activate: randomized clinical trial of BCG vaccination against infection in the elderly. Cell 2020;183:315–23. 10.1016/j.cell.2020.08.051
    1. Moorlag SJCFM, Arts RJW, van Crevel R, et al. . Non-specific effects of BCG vaccine on viral infections. Clin Microbiol Infect 2019;25:1473–8. 10.1016/j.cmi.2019.04.020
    1. Pittet LF, Curtis N. Does Bacillus Calmette-Guérin vaccine prevent herpes simplex virus recurrences? A systematic review. Rev Med Virol 2021;31:e2151. 10.1002/rmv.2151
    1. Biering-Sorensen S, Aaby P, Lund N. Early BCG-Denmark and neonatal mortality among infants weighing. Clin Infect Dis 2017;65:1183–90.
    1. Higgins JPT, Soares-Weiser K, López-López JA, et al. . Association of BCG, DTP, and measles containing vaccines with childhood mortality: systematic review. BMJ 2016;355:i5170. 10.1136/bmj.i5170
    1. Novakovic B, Messina N, Curtis N. Chapter 6 - The Heterologous Effects of Bacillus Calmette-Guérin (BCG) Vaccine and Trained Innate Immunity. In: Faustman DL, ed. The value of BCG and TNF in autoimmunity. 2nd ed. Academic Press, 2018: 71–90.
    1. Kleinnijenhuis J, Quintin J, Preijers F, et al. . Bacille Calmette-Guerin induces NOD2-dependent nonspecific protection from reinfection via epigenetic reprogramming of monocytes. Proc Natl Acad Sci U S A 2012;109:17537–42. 10.1073/pnas.1202870109
    1. Kleinnijenhuis J, Quintin J, Preijers F, et al. . BCG-induced trained immunity in NK cells: role for non-specific protection to infection. Clin Immunol 2014;155:213–9. 10.1016/j.clim.2014.10.005
    1. Freyne B, Donath S, Germano S, et al. . Neonatal BCG vaccination influences cytokine responses to Toll-like receptor ligands and heterologous antigens. J Infect Dis 2018;217:1798–808. 10.1093/infdis/jiy069
    1. Freyne B, Messina NL, Donath S, et al. . Neonatal BCG vaccination reduces interferon-γ responsiveness to heterologous pathogens in infants from a randomized controlled trial. J Infect Dis 2020;221:1999–2009. 10.1093/infdis/jiaa030
    1. Netea MG, Domínguez-Andrés J, Barreiro LB, et al. . Defining trained immunity and its role in health and disease. Nat Rev Immunol 2020;20:375–88. 10.1038/s41577-020-0285-6
    1. Kleinnijenhuis J, Quintin J, Preijers F, et al. . Long-lasting effects of BCG vaccination on both heterologous Th1/Th17 responses and innate trained immunity. J Innate Immun 2014;6:152–8. 10.1159/000355628
    1. Walk J, de Bree LCJ, Graumans W, et al. . Outcomes of controlled human malaria infection after BCG vaccination. Nat Commun 2019;10:874. 10.1038/s41467-019-08659-3
    1. Freyne B, Marchant A, Curtis N. BCG-associated heterologous immunity, a historical perspective: intervention studies in animal models of infectious diseases. Trans R Soc Trop Med Hyg 2015;109:287. 10.1093/trstmh/trv021
    1. Floc'h F, Werner GH. Increased resistance to virus infections of mice inoculated with BCG (Bacillus Calmette-Guérin). Ann Immunol 1976;127:173–86.
    1. Old LJ, Benacerraf B, Clarke DA, et al. . The role of the reticuloendothelial system in the host reaction to neoplasia. Cancer Res 1961;21:1281–300.
    1. Netea MG, Giamarellos-Bourboulis EJ, Domínguez-Andrés J, et al. . Trained immunity: a tool for reducing susceptibility to and the severity of SARS-CoV-2 infection. Cell 2020;181:969–77. 10.1016/j.cell.2020.04.042
    1. Curtis N, Sparrow A, Ghebreyesus TA, et al. . Considering BCG vaccination to reduce the impact of COVID-19. Lancet 2020;395:1545–6. 10.1016/S0140-6736(20)31025-4
    1. Harris PA, Taylor R, Thielke R, et al. . Research electronic data capture (REDCap)--a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform 2009;42:377–81. 10.1016/j.jbi.2008.08.010
    1. Food and Drug Administration . Guidance for industry: toxicity grading scale for healthy adult and adolescent volunteers enrolled in preventive vaccine clinical 2007. Available: [Accessed 8 Apr 2020].
    1. Royston P. Flexible parametric alternatives to the COX model: update. Stata J 2004;4:98–101. 10.1177/1536867X0100400112
    1. BRACE statistical analysis plan for interim analysis. Available: 10.25374/MCRI.14721309.v1 [Accessed 13 Oct 2021].
    1. Australian Government Department of Health . The BCG vaccine: information and recommendations for use in Australia. communicable diseases intelligence.
    1. Lotte A, Wasz-Höckert O, Poisson N, et al. . BCG complications. estimates of the risks among vaccinated subjects and statistical analysis of their main characteristics. Adv Tuberc Res 1984;21:107–93.
    1. Bothamley GH, Cooper E, Shingadia D. Tuberculin testing before BCG vaccination. BMJ 2003;327:243–4. 10.1136/bmj.327.7409.243
    1. Australian Technical Advisory Group on Immunisation (ATAGI) . Australian immunisation Handbook. Canberra: Australian Government Department of Health, 2018.
    1. Hendry AJ, Dey A, Beard FH, et al. . Adverse events following immunisation with Bacille Calmette-Guérin vaccination: baseline data to inform monitoring in Australia following introduction of new unregistered BCG vaccine. Commun Dis Intell Q Rep 2016;40:E470–4.
    1. New Zealand Medicines and Medical Devices Safety Authority . BCG vaccine SSI data sheet 14 March 2018. Available: [Accessed 24 Dec 2019].
    1. Pilgrim S. Administration of the Bacillus Calmette Guerin (BCG) vaccination in neonates, 2019. Available: [Accessed 24 Dec 2019].
    1. Bannister S, Sudbury E, Villanueva P, et al. . The safety of BCG revaccination: a systematic review. Vaccine 2021;39:2736–45. 10.1016/j.vaccine.2020.08.016
    1. Fine P, Carneiro I, Milstien J. Issues relating to the use of BCG in immunization programmes: a discussion document. Geneva: Department of Vaccines and Biologicals, World Health Organization, 1999.
    1. Rodrigues LC, Pereira SM, Cunha SS, et al. . Effect of BCG revaccination on incidence of tuberculosis in school-aged children in Brazil: the BCG-REVAC cluster-randomised trial. Lancet 2005;366:1290–5. 10.1016/S0140-6736(05)67145-0
    1. Randomised controlled trial of single BCG, repeated BCG, or combined BCG and killed Mycobacterium leprae vaccine for prevention of leprosy and tuberculosis in Malawi. Karonga prevention trial group. Lancet 1996;348:17–24. 10.1016/S0140-6736(96)02166-6
    1. Roth AE, Stabell Benn C, Ravn H, et al. . Effect of revaccination with BCG in early childhood on mortality: randomised trial in Guinea-Bissau. BMJ 2010;340:c671. 10.1136/bmj.c671
    1. Leentjens J, Kox M, Stokman R, et al. . BCG vaccination enhances the immunogenicity of subsequent influenza vaccination in healthy volunteers: a randomized, placebo-controlled pilot study. J Infect Dis 2015;212:1930–8. 10.1093/infdis/jiv332
    1. Padmanabhan U, Mukherjee S, Borse R. Phase II clinical trial for evaluation of BCG as potential therapy for COVID-19, 2020. Available:
    1. Moorlag SJCFM, van Deuren RC, van Werkhoven CH, et al. . Safety and COVID-19 symptoms in individuals recently vaccinated with BCG: a retrospective cohort study. Cell Rep Med 2020;1:100073. 10.1016/j.xcrm.2020.100073

Source: PubMed

3
Abonneren