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Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae
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Published on: January 17, 2014

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Streptococcus pneumoniae colonization associates with impaired adaptive immune responses against SARS-CoV-2

Elena Mitsi1, Jesús Reiné1, Britta C Urban1

  • 1Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.

The Journal of Clinical Investigation
|February 9, 2022
PubMed

Insights

Pneumococcal colonization weakens the immune response to SARS-CoV-2 (coronavirus disease 2019). This coinfection may allow the virus to evade immune defenses, potentially leading to reinfection.

Area of Science:

  • * Immunology
  • * Virology
  • * Microbiology

Background:

  • * Epidemiological data suggest pneumococci increase SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) risk.
  • * Infrequent reports of Streptococcus pneumoniae coinfection in hospitalized COVID-19 patients suggest complex interactions.
  • * Potential SARS-CoV-2 immune evasion mechanisms in the upper airway due to pneumococci.

Purpose of the Study:

  • * Investigate the relationship between SARS-CoV-2 and pneumococcal coinfection.
  • * Assess the impact of coinfection on host immune responses (antibody, cellular, inflammatory).
  • * Examine these interactions in both mild/asymptomatic and moderate/severe COVID-19 cases.

Main Methods:

  • * Studied two cohorts: healthcare workers with asymptomatic/mild SARS-CoV-2 and hospitalized patients with moderate/severe COVID-19.
  • * Systematic screening for SARS-CoV-2 infection.
  • * Assessed host immune responses to SARS-CoV-2 in the presence of pneumococcal colonization.

Main Results:

  • * Pneumococcal colonization was linked to reduced antiviral immune responses in both cohorts.
  • * Mucosal IgA levels were primarily affected in mild/asymptomatic infections.
  • * Cellular memory responses were diminished in hospitalized patients with coinfection.

Conclusions:

  • * Streptococcus pneumoniae impairs host immunity against SARS-CoV-2.
  • * Pneumococcal carriage may facilitate SARS-CoV-2 immune escape.
  • * Raises questions about pneumococcal role in immune evasion and reinfection for other respiratory viruses.
Keywords:
Adaptive immunityBacterial infectionsImmunologyT cellsVirology

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