Why the elderly appear to be more severely affected by COVID-19: The potential role of immunosenescence and CMV

Rev Med Virol. 2020 Sep;30(5):e2144. doi: 10.1002/rmv.2144. Epub 2020 Jul 15.

Abstract

The significantly higher mortality rates seen in the elderly compared with young children during the coronavirus disease 2019 (Covid-19) pandemic is likely to be driven in part by an impaired immune response in older individuals. Cytomegalovirus (CMV) seroprevalence approaches 80% in the elderly. CMV has been shown to accelerate immune ageing by affecting peripheral blood T cell phenotypes and increasing inflammatory mediated cytokines such as IL-6. The elderly with pre-existing but clinically silent CMV infection may therefore be particularly susceptible to severe Covid-19 disease and succumb to a cytokine storm which may have been promoted by CMV. Here, we evaluate the potential role of CMV in those with severe Covid-19 disease and consider how this relationship can be investigated in current research studies.

Keywords: CMV; COVID-19; immunosenescence.

Publication types

  • Review

MeSH terms

  • Age Factors
  • Aged
  • Betacoronavirus / immunology
  • Betacoronavirus / pathogenicity*
  • COVID-19
  • Child
  • Coinfection
  • Coronavirus Infections / epidemiology*
  • Coronavirus Infections / immunology
  • Coronavirus Infections / mortality
  • Coronavirus Infections / virology
  • Cytokine Release Syndrome / epidemiology*
  • Cytokine Release Syndrome / immunology
  • Cytokine Release Syndrome / mortality
  • Cytokine Release Syndrome / virology
  • Cytokines / genetics
  • Cytokines / immunology
  • Cytomegalovirus / immunology
  • Cytomegalovirus / pathogenicity*
  • Cytomegalovirus Infections / epidemiology*
  • Cytomegalovirus Infections / immunology
  • Cytomegalovirus Infections / mortality
  • Cytomegalovirus Infections / virology
  • Disease Progression
  • Humans
  • Immunosenescence*
  • Pandemics*
  • Pneumonia, Viral / epidemiology*
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / mortality
  • Pneumonia, Viral / virology
  • SARS-CoV-2
  • Seroepidemiologic Studies
  • Severity of Illness Index
  • Survival Analysis
  • T-Lymphocytes / immunology
  • T-Lymphocytes / pathology
  • T-Lymphocytes / virology

Substances

  • Cytokines