Sex Differences in Sars-CoV-2 Infection

Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Females generally mount a more robust immune response to infections and vaccination. The COVID-19 pandemic highlighted this sexual bias, with men being at higher risk...

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Bibliographic Details
Main Author: Juliano, Ana Margarida Cunha
Format: Dissertation
Language:English
Published: ProQuest Dissertations & Theses 01-01-2021
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Summary:Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Females generally mount a more robust immune response to infections and vaccination. The COVID-19 pandemic highlighted this sexual bias, with men being at higher risk of death and severe manifestations of disease. However, the underlying mechanisms remain understudied. We evaluated how B an T cells respond to SARS-CoV-2 infection and to COVID-19 vaccination. Here we show that upon SARS-CoV-2 infection, there is a spike-specific B and T cell response against the virus. Our data demonstrate that spike-specific T cells have a Tfh-like phenotype, characterized by high expression of CXCR5 and ICOS. Our findings indicate that spike-specific T cells produce IL-10 at high concentrations, which is a feature of hyperinflammation during severe SARS CoV-2 infection. Moreover, our data reveal the presence of anti-spike IgG, IgA and IgM antibodies in circulation. IgG levels correlated with the days of symptoms. Further studies are needed to understand better the sex bias and the mechanisms underlying SARS-CoV-2 infection. The type and quantity of sex hormones vary throughout a woman's life, especially during pregnancy and breastfeeding. Initial clinical trials of mRNA COVID-19 vaccines excluded lactating women, causing a scarcity of data to guide decision-making. We evaluated how BNT162b2 and mRNA-1273 vaccines impact the immune response of lactating women and the protective profile of breastmilk. We show that, upon vaccination, immune transfer to breastmilk occurs through a combination of anti-spike secretory IgA (SIgA) antibodies and spike-reactive T cells. Our data suggest that cumulative transfer of IgA might provide the infant with effective neutralization capacity. These findings put forward that breastmilk might convey both immediate, through anti-spike SIgA, as well as long-lived, via spike-reactive T cells, immune protection to the infant. Further studies are needed to determine spike-T cells functional profile.
ISBN:9798342340571