Robust T cell immunity in convalescent individuals with asymptomatic or mild #COVID-19 | bioRxiv
▻https://www.biorxiv.org/content/10.1101/2020.06.29.174888v1
SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. We systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in a large cohort of unexposed individuals as well as exposed family members and individuals with acute or convalescent COVID-19. Acute phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative family members and individuals with a history of asymptomatic or mild COVID-19 . Our collective dataset shows that #SARS-CoV-2 elicits robust memory T cell responses akin to those observed in the context of successful vaccines, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19 also in seronegative individuals.
Immunity to COVID-19 is probably higher than tests have shown
▻https://medicalxpress.com/news/2020-06-immunity-covid-higher-shown.html
“T cells are a type of white blood cells that are specialized in recognizing virus-infected cells, and are an essential part of the immune system,” says Marcus Buggert, assistant professor at the Center for Infectious Medicine, Karolinska Institutet, and one of the paper’s main authors. “Advanced analyses have now enabled us to map in detail the T-cell response during and after a COVID-19 infection. Our results indicate that roughly twice as many people have developed T-cell immunity compared with those who we can detect antibodies in .”
Coronavirus: Immunity may be more widespread than tests suggest - BBC News
▻https://www.bbc.com/news/health-53248660
T-cells are very complex and much harder to identify than antibodies, requiring specialist labs and small batches of samples being tested by hand over the course of days.
This means mass testing for T-cells is not a very likely prospect at the moment.