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

Mitsi, Elena, Reiné, Jesús, Urban, Britta ORCID:, SolorzanoGonzalez, Carla, Nikolaou, Elissavet, Hyder-Wright, Angela, Pojar, Sherin ORCID:, Howard, Ashleigh, Hitchins, Lisa, Glynn, Sharon, Farrar, Madlen, Liatsikos, Konstantin, Collins, Andrea ORCID:, Walker, Naomi ORCID:, Hill, Helen, German, Esther, Cheliotis, Katerina, Byrne, Rachel, Williams, Chris, CubasAtienzar, Ana, Fletcher, Tom, Adams, Emily ORCID:, Draper, Simon J, Pulido, David, Beavon, Rohini, Theilacker, Christian, Begier, Elizabeth, Jodar, Luis, Gessner, Bradford D and Ferreira, Daniela ORCID: (2022) 'Streptococcus pneumoniae colonization associates with impaired adaptive immune responses against SARS-CoV-2.'. Journal of Clinical Investigation, Vol 132, Issue 7, e157124.

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Although recent epidemiological data suggest that pneumococci may contribute to the risk of SARS-CoV-2 disease, cases of co-infection with Streptococcus pneumoniae in COVID-19 patients during hospitalisation have been reported infrequently. This apparent contradiction may be explained by interactions of SARS-CoV-2 and pneumococcus in the upper airway, resulting in the escape of SARS-CoV-2 from protective host immune responses.


Here, we investigated the relationship of these two respiratory pathogens in two distinct cohorts of a) healthcare workers with asymptomatic or mildly symptomatic SARS-CoV-2 infection identified by systematic screening and b) patients with moderate to severe disease who presented to hospital. We assessed the effect of co-infection on host antibody, cellular and inflammatory responses to the virus.


In both cohorts, pneumococcal colonisation was associated with diminished anti-viral immune responses, which affected primarily mucosal IgA levels among individuals with mild or asymptomatic infection and cellular memory responses in infected patients.


Our findings suggest that S. pneumoniae impairs host immunity to SARS-CoV-2 and raises the question if pneumococcal carriage also enables immune escape of other respiratory viruses and facilitates reinfection occurrence.


ISRCTN89159899 for FASTER study and identifier: NCT03502291 for LAIV study.

Item Type: Article
Subjects: QW Microbiology and Immunology > Immune Responses > QW 700 Infection. Mechanisms of infection and resistance.
WC Communicable Diseases > Infection. Bacterial Infections > Bacterial Infections > WC 210 Streptococcal infections (General or not elsewhere classified)
WC Communicable Diseases > Infection. Bacterial Infections > Bacterial Infections > WC 217 Pneumococcal infections
WC Communicable Diseases > Virus Diseases > Viral Respiratory Tract Infections. Respirovirus Infections > WC 506 COVID-19
Faculty: Department: Biological Sciences > Department of Tropical Disease Biology
Clinical Sciences & International Health > Clinical Sciences Department
Digital Object Identifer (DOI):
Depositing User: Julie Franco
Date Deposited: 28 Mar 2022 10:52
Last Modified: 24 Jun 2022 10:29


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