Factor or Comorbidity Impact on COVID-19 Proposed impact on innate immune responses Ref
Age
Increased CFR >80 - 14.8% vf 2.3% 70-79 – 8.0% Increased oxidative stress, decreased IFN responses. Elevated proinflammatory cytokines.
(96–98)
Blood groups Higher risk in blood group A and protective effect in blood group O in a cohort of 1,610 cases Neutralizing antibodies against protein-linked N-glycans on SARS-CoV-2, or stabilisation of vWF. (99–101)
Cardiovascular Disease
Increased CFR 10.5% vf 2.3%
Infection of cardiomyocytes, Increased myocarditis, impact of drugs on RAS. Increase levels of vWF.
(96,102)
Cancer 4.7%, 5.6% unknown (96,103)
Diabetes mellitis 7.3% Reduced ACE2 levels in diabetes already predispose to a proinflammatory environment. Increased IL-6 levels. Increased levels of vWF (96,104)
Gender Increased CFR for males across all ages Differential expression levels of ACE2, hormonal regulation of immune reposes, IL-6 higher in men (105,106)
Ethnicity
Higher risk in some ethnic groups not due to socioeconomic conditions
Difference in TLR expression, levels of IL-6 and TNFα. Reduced levels of VitD.
(107,108)
Obesity BMI >25 or 30 increased risk of severe pneumonia by 86% and 140% Dysregulated NK cells, increased numbers of myeloid cells in adipose tissues and expression of ACE2 by adipocytes (109,110)