T-cells from common colds can provide protection against COVID-19 - study

[Mary Wilson]

January 10, 2022 2:16 PM UTC
By Alistair Smout

LONDON, Jan 10 (Reuters) - High levels of T-cells from common cold coronaviruses can provide protection against COVID-19, an Imperial College London study published on Monday has found, which could inform approaches for second-generation vaccines.

Immunity against COVID-19 is a complex picture, and while there is evidence of waning antibody levels six months after vaccination, T-cells are also believed to play a vital role in providing protection.

The study, which began in September 2020, looked at levels of cross-reactive T-cells generated by previous common colds in 52 household contacts of positive COVID-19 cases shortly after exposure, to see if they went on to develop infection.

It found that the 26 who did not develop infection had significantly higher levels of those T-cells than people who did get infected. Imperial did not say how long protection from the T-cells would last.

"We found that high levels of pre-existing T cells, created by the body when infected with other human coronaviruses like the common cold, can protect against COVID-19 infection," study author Dr Rhia Kundu said.

https://www.reuters.com/business/hea...dy-2022-01-10/

NOTE: Study link below

 

[Mary Wilson]

Cross-reactive memory T cells associate with protection against SARS-CoV-2 infection in COVID-19 contacts

Published: 10 January 2022

DOI https://doi.org/10.1038/s41467-021-27674-x

Rhia Kundu, Janakan Sam Narean, Lulu Wang, Joseph Fenn, Timesh Pillay, Nieves Derqui Fernandez, Emily Conibear, Aleksandra Koycheva, Megan Davies, Mica Tolosa-Wright, Seran Hakki, Robert Varro, Eimear McDermott, Sarah Hammett, Jessica Cutajar, Ryan S. Thwaites, Eleanor Parker, Carolina Rosadas, Myra McClure, Richard Tedder, Graham P. Taylor, Jake Dunning & Ajit Lalvani

Abstract

Cross-reactive immune responses to SARS-CoV-2 have been observed in pre-pandemic cohorts and proposed to contribute to host protection. Here we assess 52 COVID-19 household contacts to capture immune responses at the earliest timepoints after SARS-CoV-2 exposure. Using a dual cytokine FLISpot assay on peripheral blood mononuclear cells, we enumerate the frequency of T cells specific for spike, nucleocapsid, membrane, envelope and ORF1 SARS-CoV-2 epitopes that cross-react with human endemic coronaviruses. We observe higher frequencies of cross-reactive (p = 0.0139), and nucleocapsid-specific (p = 0.0355) IL-2-secreting memory T cells in contacts who remained PCR-negative despite exposure (n = 26), when compared with those who convert to PCR-positive (n = 26); no significant difference in the frequency of responses to spike is observed, hinting at a limited protective function of spike-cross-reactive T cells. Our results are thus consistent with pre-existing non-spike cross-reactive memory T cells protecting SARS-CoV-2-naïve contacts from infection, thereby supporting the inclusion of non-spike antigens in second-generation vaccines.

https://www.nature.com/articles/s41467-021-27674-x.pdf

 

[sharon sanders]

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