A cytokine super cyclone in COVID-19 patients with risk factors: the therapeutic potential of BCG immunization

Cytokine Growth Factor Rev. 2020 Aug;54:32-42. doi: 10.1016/j.cytogfr.2020.06.014. Epub 2020 Jul 1.


The seventh human coronavirus SARS-CoV2 belongs to the cluster of extremely pathogenic coronaviruses including SARS-CoV and MERS-CoV, which can cause fatal lower respiratory tract infection. Likewise, SARS-CoV2 infection can be fatal as the disease advances to pneumonia, followed by acute respiratory distress syndrome (ARDS). The development of lethal clinical symptons is associated with an exaggerated production of inflammatory cytokines, referred to as the cytokine storm, is a consequence of a hyperactivated immune response aginst the infection. In this article, we discuss the pathogenic consequences of the cytokine storm and its relationship with COVID-19 associated risk factors. The increased pro-inflammatory immune status in patients with risk factors (diabetes, hypertension, cardiovascular disease, COPD) exacerbates the Cytokine-storm of COVID-19 into a 'Cytokine Super Cyclone'. We also evaluate the antiviral immune responses provided by BCG vaccination and the potential role of 'trained immunity' in early protection against SARS-CoV2.

Keywords: BCG; COVID-19(SARS Cov2); Co-morbidity; Coronavirus; Cytokine; Growth factors.

Publication types

  • Review

MeSH terms

  • Antiviral Agents / therapeutic use
  • BCG Vaccine / therapeutic use*
  • Betacoronavirus / immunology
  • COVID-19
  • Cardiovascular Diseases / pathology
  • Coronavirus Infections / drug therapy
  • Coronavirus Infections / immunology
  • Coronavirus Infections / prevention & control*
  • Cytokine Release Syndrome / immunology
  • Cytokine Release Syndrome / pathology
  • Cytokine Release Syndrome / prevention & control*
  • Cytokines / blood*
  • Diabetes Mellitus / pathology
  • Humans
  • Hypertension / pathology
  • Middle East Respiratory Syndrome Coronavirus / immunology
  • Mycobacterium bovis / immunology
  • Pandemics / prevention & control*
  • Pneumonia, Viral / drug therapy
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / prevention & control*
  • Pulmonary Disease, Chronic Obstructive / pathology
  • Risk Factors
  • SARS-CoV-2
  • Severe Acute Respiratory Syndrome / immunology
  • Vaccination


  • Antiviral Agents
  • BCG Vaccine
  • Cytokines