Effect of BCG Revaccination on Occupationally Exposed Medical Personnel Vaccinated against SARS-CoV-2

• Published in: Cells (Basel, Switzerland) Switzerland), 2021-11, Vol.10 (11), p.3179
• Main Authors: Ramos-Martinez, Espiridión, Falfán-Valencia, Ramcés, Pérez-Rubio, Gloria, Andrade, Warrison Athanasio, Rojas-Serrano, Jorge, Ambrocio-Ortiz, Enrique, Galicia-Álvarez, Dennisse S., Bárcenas-Montiel, Isaac, Velasco-Medina, Andrea, Velázquez-Sámano, Guillermo
• Format: Article
• Language: English
• Subjects: Alleles; Antibodies; Anticoagulants; BCG; Coronaviruses; COVID-19; COVID-19 vaccines; Cytokines; Disease transmission; Drb1 protein; Gene frequency; Granulocyte-macrophage colony-stimulating factor; Histocompatibility antigen HLA; Hospitals; IL-1β; Influenza; Interleukin 12; Interleukin 13; Interleukin 18; Interleukin 4; Interleukin 6; Lymphocytes T; Medical personnel; neutralizing antibodies; Pandemics; Pathogens; Patients; Placebos; Proteins; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Tuberculosis; Tumor necrosis factor-TNF; Tumor necrosis factor-α; vaccination; Vaccines; Viruses
• ISSN: 2073-4409; 2073-4409
• DOI: 10.3390/cells10113179

The production of specific neutralizing antibodies by individuals is thought to be the best option for reducing the number of patients with severe COVID-19, which is the reason why multiple vaccines are currently being administered worldwide. We aimed to explore the effect of revaccination with BCG, on the response to a subsequent anti-SARS-CoV-2 vaccine, in persons occupationally exposed to COVID-19 patients. Two groups of 30 randomized participants were selected: one group received a BCG revaccination, and the other group received a placebo. Subsequently, both groups were vaccinated against SARS-CoV-2. After each round of vaccination, the serum concentration of Th1/Th2 cytokines was determined. At the end of the protocol, neutralizing antibodies were determined and the HLA-DRB loci were genotyped. The participants from the BCG group and anti-SARS-CoV-2 vaccine group had increased serum cytokine concentrations (i.e., IL-1β, IL-4, IL-6, IL-12p70, IL-13, IL-18, GM-CSF, INF-γ, and TNF-α) and higher neutralizing antibody titers, compared to the group with Placebo–anti-SARS-CoV-2. Twelve HLA-DRB1 alleles were identified in the Placebo–anti-SARS-CoV-2 group, and only nine in the group revaccinated with BCG. The DRB1*04 allele exhibited increased frequency in the Placebo–anti-SARS-CoV-2 group; however, no confounding effects were found with this allele. We conclude that revaccination with BCG synergizes with subsequent vaccination against SARS-CoV-2 in occupationally exposed personnel.