{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,11]],"date-time":"2026-07-11T19:49:38Z","timestamp":1783799378139,"version":"3.55.0"},"reference-count":20,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T00:00:00Z","timestamp":1638316800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2021,12,20]],"date-time":"2021-12-20T00:00:00Z","timestamp":1639958400000},"content-version":"vor","delay-in-days":19,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Infect Dis"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>From May 2020 to January 2021, we enrolled 1233 health care workers (HCW) from Danish Hospitals in a randomized trial evaluating whether Bacille Calmette-Gu\u00e9rin (BCG) provides protection against COVID-19. Participants were randomized 1:1 to BCG vs saline and followed for 6\u00a0months. From December 2020, Covid-19 vaccines were offered to the HCW. In most cases, BCG vaccination results in a characteristic scar. Reactivation of the BCG scar has been described in children during viral infections and following influenza vaccination, but is mostly associated to Kawasaki\u2019s disease, a disease entity with pathogenesis likely similar to the child Covid-19 complication MIS-C: Multi-System Inflammatory Syndrome. Reactivation of scars after neonatal BCG vaccination has recently been described in four women after Covid-19 mRNA vaccination. Two of our trial participants experienced reactivation of their novel BCG scars after receiving mRNA Covid-19 vaccination 6 to 8\u00a0months post-BCG.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Case presentations<\/jats:title>\n                <jats:p>Two female HCW participants that had been randomly allocated to BCG in the BCG-DENMARK-COVID trial, spontaneously reported itching and secretion at the BCG scar site after having received mRNA Covid-19 vaccination (Moderna and Pfizer-BioNTech) 6 to 8\u00a0months following inclusion and BCG vaccination. One participant, who had a larger BCG skin reaction, noticed re-appearing symptoms after both the first and the second COVID-vaccine dose, while the other participant only noted symptoms after the second dose. Both had been BCG vaccinated during childhood, and no reactivation was noted in the older scars. No treatment was needed or provided.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>The reactivation of the BCG scar after receiving mRNA vaccine might have been caused by cross-reactivity between BCG and SARS-CoV-2. In both cases, the symptoms were bothersome, but self-limiting and left no sequelae. The risk of reactivation at the scar site is thus not a reason to avoid vaccination with either vaccine.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s12879-021-06949-0","type":"journal-article","created":{"date-parts":[[2021,12,20]],"date-time":"2021-12-20T09:02:51Z","timestamp":1639990971000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Reactivation of BCG vaccination scars after vaccination with mRNA-Covid-vaccines: two case reports"],"prefix":"10.1186","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9847-6055","authenticated-orcid":false,"given":"Libin","family":"Mohamed","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne Marie Rosendahl","family":"Madsen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frederik","family":"Schaltz-Buchholzer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Ostenfeld","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mihai G.","family":"Netea","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christine Stabell","family":"Benn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Poul-Erik","family":"Kofoed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2021,12,20]]},"reference":[{"issue":"3","key":"6949_CR1","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1093\/ije\/dyh392","volume":"34","author":"A Roth","year":"2005","unstructured":"Roth A, et al. BCG vaccination scar associated with better childhood survival in Guinea-Bissau. Int J Epidemiol. 2005;34(3):540\u20137.","journal-title":"Int J Epidemiol"},{"issue":"9","key":"6949_CR2","doi-asserted-by":"publisher","first-page":"e002993","DOI":"10.1136\/bmjgh-2020-002993","volume":"5","author":"F Schaltz-Buchholzer","year":"2020","unstructured":"Schaltz-Buchholzer F, et al. BCG skin reactions by 2 months of age are associated with better survival in infancy: a prospective observational study from Guinea-Bissau. BMJ Glob Health. 2020;5(9):e002993.","journal-title":"BMJ Glob Health"},{"key":"6949_CR3","doi-asserted-by":"publisher","first-page":"i5170","DOI":"10.1136\/bmj.i5170","volume":"355","author":"JP Higgins","year":"2016","unstructured":"Higgins JP, et al. Association of BCG, DTP, and measles containing vaccines with childhood mortality: systematic review. Bmj. 2016;355:i5170.","journal-title":"Bmj"},{"issue":"7","key":"6949_CR4","doi-asserted-by":"publisher","first-page":"1183","DOI":"10.1093\/cid\/cix525","volume":"65","author":"S Biering-S\u00f8rensen","year":"2017","unstructured":"Biering-S\u00f8rensen S, et al. Early BCG-Denmark and neonatal mortality among infants weighing <2500 g: a randomized controlled trial. Clin Infect Dis. 2017;65(7):1183\u201390.","journal-title":"Clin Infect Dis"},{"issue":"4","key":"6949_CR5","doi-asserted-by":"publisher","first-page":"624","DOI":"10.1093\/infdis\/jiy544","volume":"219","author":"F Schaltz-Buchholzer","year":"2018","unstructured":"Schaltz-Buchholzer F, et al. Early BCG vaccination, hospitalizations, and hospital deaths: analysis of a secondary outcome in 3 randomized trials from Guinea-Bissau. J Infect Dis. 2018;219(4):624\u201332.","journal-title":"J Infect Dis"},{"issue":"1","key":"6949_CR6","doi-asserted-by":"publisher","first-page":"799","DOI":"10.1186\/s13063-020-04714-3","volume":"21","author":"AMR Madsen","year":"2020","unstructured":"Madsen AMR, et al. Using BCG vaccine to enhance non-specific protection of health care workers during the COVID-19 pandemic: a structured summary of a study protocol for a randomised controlled trial in Denmark. Trials. 2020;21(1):799.","journal-title":"Trials"},{"key":"6949_CR7","doi-asserted-by":"publisher","first-page":"e20190390","DOI":"10.1590\/0037-8682-0390-2019","volume":"53","author":"Y Chavarri-Guerra","year":"2019","unstructured":"Chavarri-Guerra Y, Soto-Perez-de-Celis E. Erythema at the bacillus Calmette-Guerin scar after influenza vaccination. Rev Soc Bras Med Trop. 2019;53:e20190390.","journal-title":"Rev Soc Bras Med Trop"},{"issue":"10","key":"6949_CR8","doi-asserted-by":"publisher","first-page":"1229","DOI":"10.1111\/1346-8138.13365","volume":"43","author":"M Kondo","year":"2016","unstructured":"Kondo M, Goto H, Yamamoto S. First case of redness and erosion at bacillus Calmette-Gu\u00e9rin inoculation site after vaccination against influenza. J Dermatol. 2016;43(10):1229\u201331.","journal-title":"J Dermatol"},{"issue":"30","key":"6949_CR9","doi-asserted-by":"publisher","first-page":"E1178","DOI":"10.1503\/cmaj.210696","volume":"193","author":"DW Lim","year":"2021","unstructured":"Lim DW, Ng DHL, Low JG. Bacillus Calmette-Guerin scar flare after an mRNA SARS-CoV-2 vaccine. CMAJ. 2021;193(30):E1178.","journal-title":"CMAJ"},{"key":"6949_CR10","doi-asserted-by":"publisher","DOI":"10.7759\/cureus.14453","author":"EZ Lopatynsky-Reyes","year":"2021","unstructured":"Lopatynsky-Reyes EZ, Acosta-Lazo H, Ulloa-Gutierrez R, et al. BCG scar local skin inflammation as a novel reaction following mRNA COVID-19 vaccines in two international healthcare workers. Cureus. 2021. https:\/\/doi.org\/10.7759\/cureus.14453.","journal-title":"Cureus."},{"issue":"4","key":"6949_CR11","doi-asserted-by":"publisher","first-page":"351","DOI":"10.1620\/tjem.228.351","volume":"228","author":"Y Kakisaka","year":"2012","unstructured":"Kakisaka Y, et al. Human herpes virus type 6 can cause skin lesions at the BCG inoculation site similar to Kawasaki Disease. Tohoku J Exp Med. 2012;228(4):351\u20133.","journal-title":"Tohoku J Exp Med"},{"issue":"1","key":"6949_CR12","doi-asserted-by":"publisher","first-page":"251","DOI":"10.1186\/s12887-019-1635-z","volume":"19","author":"S Muthuvelu","year":"2019","unstructured":"Muthuvelu S, et al. Measles infection causing Bacillus Calmette-Gu\u00e9rin reactivation: a case report. BMC Pediatr. 2019;19(1):251.","journal-title":"BMC Pediatr"},{"issue":"2","key":"6949_CR13","doi-asserted-by":"publisher","first-page":"89","DOI":"10.11622\/smedj.2018084","volume":"60","author":"ACE Loh","year":"2019","unstructured":"Loh ACE, Kua PHJ, Tan ZL. Erythema and induration of the Bacillus Calmette-Gu\u00e9rin site for diagnosing Kawasaki disease. Singapore Med J. 2019;60(2):89\u201393.","journal-title":"Singapore Med J"},{"issue":"4","key":"6949_CR14","doi-asserted-by":"publisher","first-page":"256","DOI":"10.5455\/msm.2014.26.256-260","volume":"26","author":"MS Rezai","year":"2014","unstructured":"Rezai MS, Shahmohammadi S. Erythema at BCG inoculation site in Kawasaki disease patients. Mater Sociomed. 2014;26(4):256\u201360.","journal-title":"Mater Sociomed"},{"issue":"11","key":"6949_CR15","doi-asserted-by":"publisher","first-page":"e276","DOI":"10.1016\/S1473-3099(20)30651-4","volume":"20","author":"L Jiang","year":"2020","unstructured":"Jiang L, et al. COVID-19 and multisystem inflammatory syndrome in children and adolescents. Lancet Infect Dis. 2020;20(11):e276\u201388.","journal-title":"Lancet Infect Dis"},{"issue":"3","key":"6949_CR16","doi-asserted-by":"publisher","first-page":"273","DOI":"10.1111\/j.0300-9475.2004.01471.x","volume":"60","author":"AW Olsen","year":"2004","unstructured":"Olsen AW, et al. The influence of remaining live BCG organisms in vaccinated mice on the maintenance of immunity to tuberculosis. Scand J Immunol. 2004;60(3):273\u20137.","journal-title":"Scand J Immunol"},{"issue":"7","key":"6949_CR17","doi-asserted-by":"publisher","first-page":"1049","DOI":"10.1086\/433177","volume":"41","author":"T Puthanakit","year":"2005","unstructured":"Puthanakit T, et al. Immune reconstitution syndrome due to bacillus Calmette-Gu\u00e9rin after initiation of antiretroviral therapy in children with HIV infection. Clin Infect Dis. 2005;41(7):1049\u201352.","journal-title":"Clin Infect Dis"},{"issue":"41","key":"6949_CR18","doi-asserted-by":"publisher","first-page":"6352","DOI":"10.1016\/j.vaccine.2020.08.045","volume":"38","author":"Y Tomita","year":"2020","unstructured":"Tomita Y, et al. BCG vaccine may generate cross-reactive T cells against SARS-CoV-2: in silico analyses and a hypothesis. Vaccine. 2020;38(41):6352\u20136.","journal-title":"Vaccine"},{"key":"6949_CR19","doi-asserted-by":"crossref","unstructured":"Eggenhuizen PJ, et al. BCG vaccine derived peptides induce SARS-CoV-2 T cell cross-reactivity. medRxiv. 2020. 2020.11.21.20236018.","DOI":"10.1101\/2020.11.21.20236018"},{"key":"6949_CR20","doi-asserted-by":"publisher","first-page":"151600","DOI":"10.1016\/j.anndiagpath.2020.151600","volume":"48","author":"G Nuovo","year":"2020","unstructured":"Nuovo G, et al. Strong homology between SARS-CoV-2 envelope protein and a Mycobacterium sp. antigen allows rapid diagnosis of Mycobacterial infections and may provide specific anti-SARS-CoV-2 immunity via the BCG vaccine. Ann Diagn Pathol. 2020;48:151600.","journal-title":"Ann Diagn Pathol"}],"container-title":["BMC Infectious Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12879-021-06949-0.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12879-021-06949-0\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12879-021-06949-0.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,12,20]],"date-time":"2021-12-20T09:08:28Z","timestamp":1639991308000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmcinfectdis.biomedcentral.com\/articles\/10.1186\/s12879-021-06949-0"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12]]},"references-count":20,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2021,12]]}},"alternative-id":["6949"],"URL":"https:\/\/doi.org\/10.1186\/s12879-021-06949-0","relation":{},"ISSN":["1471-2334"],"issn-type":[{"value":"1471-2334","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12]]},"assertion":[{"value":"12 May 2021","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"6 December 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"20 December 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Written informed consent was obtained from both patients for publication of this case report.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"1264"}}