New Data on T Cells and the Coronavirus
It&#x27;s not new, it&#x27;s more evidence:<p>At the end of May, however, an immunological study by the University of Zurich was published, which for the first time showed that the usual antibody tests that measure antibodies in the blood (IgG and IgM) can detect at most about one fifth of all coronavirus infections.<p><a href="https:&#x2F;&#x2F;www.biorxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.05.21.108308v1" rel="nofollow">https:&#x2F;&#x2F;www.biorxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.05.21.108308v1</a><p>At the same time, the Swiss study may explain why children usually develop no symptoms (due to frequent contact with previous corona cold viruses), and why even hotspots such as New York City found an antibody prevalence (IgG&#x2F;IgM) of at most 20% – as this already corresponds to herd immunity.<p>The Swiss study has in the meantime been confirmed by several more studies:<p>A Swedish study showed that people with mild or asymptomatic disease often neutralized the virus with T-cells without the need to produce antibodies. Overall, T-cell immunity was about twice as common as antibody immunity.<p><a href="https:&#x2F;&#x2F;news.ki.se&#x2F;immunity-to-covid-19-is-probably-higher-than-tests-have-shown" rel="nofollow">https:&#x2F;&#x2F;news.ki.se&#x2F;immunity-to-covid-19-is-probably-higher-t...</a><p>A large Spanish antibody study published in Lancet showed that less than 20% of symptomatic people and about 2% of asymptomatic people had IgG antibodies.<p><a href="https:&#x2F;&#x2F;www.thelancet.com&#x2F;journals&#x2F;lancet&#x2F;article&#x2F;PIIS0140-6736(20)31483-5&#x2F;fulltext" rel="nofollow">https:&#x2F;&#x2F;www.thelancet.com&#x2F;journals&#x2F;lancet&#x2F;article&#x2F;PIIS0140-6...</a><p>A German study (preprint) showed that 81% of the people who had not yet had contact with the new corona virus already had cross-reactive T-cells and thus a certain background immunity (due to contact with previous corona cold viruses).<p><a href="https:&#x2F;&#x2F;www.researchsquare.com&#x2F;article&#x2F;rs-35331&#x2F;v1" rel="nofollow">https:&#x2F;&#x2F;www.researchsquare.com&#x2F;article&#x2F;rs-35331&#x2F;v1</a><p>A Chinese study in the journal Nature showed that in 40% of asymptomatic persons and in 12.9% of symptomatic persons no IgG antibodies are detectable after the recovery phase.<p><a href="https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;s41591-020-0965-6" rel="nofollow">https:&#x2F;&#x2F;www.nature.com&#x2F;articles&#x2F;s41591-020-0965-6</a><p>Another Chinese study with almost 25,000 clinic employees in Wuhan showed that at most one fifth of the presumably infected employees had IgG antibodies (press article).<p><a href="https:&#x2F;&#x2F;www.medrxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.06.13.20130252v1" rel="nofollow">https:&#x2F;&#x2F;www.medrxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.06.13.20130252v...</a><p>A small French study (preprint) showed that six of eight infected family members of Covid patients developed a temporary T-cell immunity without antibodies.<p><a href="https:&#x2F;&#x2F;www.medrxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.06.21.20132449v1" rel="nofollow">https:&#x2F;&#x2F;www.medrxiv.org&#x2F;content&#x2F;10.1101&#x2F;2020.06.21.20132449v...</a>