From Cedars-Sinai in Los Angeles:
https://www.jci.org/articles/view/145157
From the paper:
Quote:
BACKGROUND. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused over one million deaths worldwide, thus there is an urgent need to develop preventive and therapeutic strategies. The anti-tuberculosis vaccine Bacillus Calmette-Gurin (BCG) demonstrates non-specific protective innate immune-boosting effects. Here, we determined if history of BCG vaccination was associated with decreased SARS-CoV-2 infection and seroconversion in a retrospective observational study of a diverse cohort of health care workers (HCWs).
METHODS. We assessed SARS-CoV-2 seroprevalence and collected medical questionnaires, including BCG vaccination status and pre-existing demographic and clinical characteristics, from an observational cohort of HCWs in a multi-site Los Angeles healthcare organization. We used multi-variate analysis to estimate if history of BCG vaccination was associated with decreased rates of SARS-CoV-2 infection and seroconversion.
RESULTS. Of the 6,201 HCWs, 29.6% reported a history of BCG vaccination whereas 68.9% did not receive BCG vaccination. Seroprevalence of anti-SARS-CoV-2 IgG as well as incidence of self-reported clinical symptoms associated with COVID-19 were significantly decreased among HCWs with a history of BCG vaccination compared to those without BCG vaccination. After adjusting for age and sex, we found that history of BCG vaccination, but not meningococcal, pneumococcal or influenza vaccination, was associated with decreased SARS-CoV-2 IgG seroconversion.
CONCLUSIONS. History of BCG vaccination was associated with decreased seroprevalence of anti-SARS-CoV-2 IgG and reduced reported COVID-19-related clinical symptoms in this cohort of HCWs. Therefore, large randomized prospective clinical trials of BCG vaccination are urgently needed to confirm if BCG vaccination can induced a protective effect against SARS-CoV2 infection.
FUNDING. This work was supported by the National Institutes of Health, National Cancer Institute (U54 CA26059) and the Erika J. Glazer Family Foundation. Key words: SARS-CoV-2, COVID-19, Bacillus Calmette-Gurin, BCG, anti-SARS-CoV-2 IgG, healthcare workers, trained immunity.
https://www.jci.org/articles/view/145157
From the paper:
Quote:
In our cohort of HCWs, we detected an absolute 3.5% seroprevalence rate of anti-SARS CoV-2 IgG, indicating that a substantial proportion of our cohort participants were previously infected with SARS-CoV-2. This seroprevalence is lower than that reported among HCWs in the New York City area (13.7%)(35), which experienced a more severe outbreak, however it is relatively close to the seroprevalence previously reported in adults from the Los Angeles county area mid-April (36). Our model (statistically adjusted for sex and age) confirmed that only individuals with history of BCG-vaccination, and not meningococcal, pneumovax or influenza vaccination, are less likely to have a SARS-CoV-2 IgG index >0.4. This finding was found across a range of different COVID-19 exposure risks, including among participants working in high-risk settings such as COVID-19 dedicated ICUs. Furthermore, individuals with history of BCG vaccination were less likely to report COVID-19 related symptoms. Thus, BCG-vaccinated individuals may have been less sick and therefore produced fewer anti-SARS-CoV-2 antibodies, or may have mounted a more efficient cellular immune response against SARS-CoV-2.