COVID-19 and Preexisting Comorbidities: Risks, Synergies, and Clinical Outcomes

Front Immunol. 2022 May 27:13:890517. doi: 10.3389/fimmu.2022.890517. eCollection 2022.


Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated symptoms, named coronavirus disease 2019 (COVID-19), have rapidly spread worldwide, resulting in the declaration of a pandemic. When several countries began enacting quarantine and lockdown policies, the pandemic as it is now known truly began. While most patients have minimal symptoms, approximately 20% of verified subjects are suffering from serious medical consequences. Co-existing diseases, such as cardiovascular disease, cancer, diabetes, and others, have been shown to make patients more vulnerable to severe outcomes from COVID-19 by modulating host-viral interactions and immune responses, causing severe infection and mortality. In this review, we outline the putative signaling pathways at the interface of COVID-19 and several diseases, emphasizing the clinical and molecular implications of concurring diseases in COVID-19 clinical outcomes. As evidence is limited on co-existing diseases and COVID-19, most findings are preliminary, and further research is required for optimal management of patients with comorbidities.

Keywords: COVID-19; cancer; cardiovascular disease; coronavirus disease 2019; diabetes; immune responses; treatment implications.

Publication types

  • Review

MeSH terms

  • COVID-19* / epidemiology
  • Communicable Disease Control
  • Humans
  • Pandemics
  • Quarantine
  • SARS-CoV-2