Background: Circulating SARS-CoV-2 RNA may represent a more reliable indicator of infection than nasal RNA, but RT-qPCR lacks diagnostic sensitivity for blood samples. Methods: A CRISPR-augmented RT-PCR assay that sensitively detects SARS-CoV-2 RNA was employed to analyze viral RNA kinetics in longitudinal plasma samples from nonhuman primates (NHP) after virus exposure; to evaluate the utility of blood SARS-CoV-2 RNA detection for COVID-19 diagnosis in adults cases confirmed by nasal/nasopharyngeal swab RT-PCR results; and to identify suspected COVID-19 cases in pediatric and at-risk adult populations with negative nasal swab RT-qPCR results. All blood samples were analyzed by RT-qPCR to allow direct comparisons. Results: CRISPR-augmented RT-PCR consistently detected SARS-CoV-2 RNA in the plasma of experimentally infected NHPs from 1 to 28 days post-infection, and these increases preceded and correlated with rectal swab viral RNA increases. In a patient cohort (n=159), this blood-based assay demonstrated 91.2% diagnostic sensitivity and 99.2% diagnostic specificity versus a comparator RT-qPCR nasal/nasopharyngeal test, while RT-qPCR exhibited 44.1% diagnostic sensitivity and 100% specificity for the same blood samples. This CRISPR-augmented RT-PCR assay also accurately identified COVID-19 patients with one or more negative nasal swab RT-qPCR result. Conclusion: Results of this study indicate that sensitive detection of SARS-CoV-2 RNA in blood by CRISPR-augmented RT-PCR permits accurate COVID-19 diagnosis, and can detect COVID-19 cases with transient or negative nasal swab RT-qPCR results, suggesting that this approach could improve COVID-19 diagnosis and the evaluation of SARS-CoV-2 infection clearance, and predict the severity of infection.

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SARS CoV-2 in children or special populations post-infection has not been well studied. Asthma is a heterogenous disease marked by chronic airway inflammation; triggers include cockroaches (CRA), and other inhaled irritants. Asthma also has links to viral infections like respiratory syncytial virus (RSV). Additionally, some with moderate to severe asthma are more likely to be hospitalized with COVID. T cells play key roles in asthma and control of viruses such; however, there is limited information connecting T cell responses in people with asthma to viral infections. We aimed to evaluate T cells and antibodies in an asthma confirmed cohort. Thirty-five children aged 5–17 years were included. We measured SARS CoV-2 spike (S) and Nucleoprotein (N) plasma antibody responses or effector functions and CD4, CD8 T cells specific to CRA or peptide pools made from RSV, S and N antigen using an activation induced markers (AIM) assay. Surprisingly, in this population many CD4 and CD8 T-cell AIM responses to S, N, CRA, and RSV were significantly associated, particularly for CD8 T-cells (Spearmans r = 0.57–0.76) and the restimulation antigens CRA and RSV. N-specific CD4 AIM was the only immune measure to correlate to a recent asthma attack within a month of the blood collection visit, though anti-N antibodies, CD4 AIM to CRA, RSV or CD8 AIM to CRA, RSV, or N antigens also correlated with asthmatic outcomes (e.g., ER visits, night waking from symptoms, etc.) whereas allergen specific IgE or anti-S IgG did not. Taken together these results indicate an immunological association between viral infection and asthma, broadly allowing for the conjecture that viral infections, in particular RSV and SARS-CoV-2 could act together as possible triggers of asthma.

Pregnancy is associated with a higher risk of adverse symptoms and outcomes for most infectious diseases, including SARS-CoV-2. These adverse risks are also observed in neonates. Antibodies provide protection against SARS-CoV-2 infection, and have been reported after maternal vaccination, maternal infection, and through passive transfer from mother to fetus in utero. However, it is unclear whether the magnitude or quality of maternally-derived fetal antibodies differs in the context of infection or vaccination. Here, we evaluated 93 paired maternal and neonatal umbilical cord blood plasma samples collected between October 2020 and February 2022 from a birth cohort of pregnant women from the greater New Orleans area. Histories of SARS-CoV-2 infection or vaccination were obtained. Humoral immunity was profiled for the levels of spike-specific antibodies and induction of antiviral humoral immune functions, including neutralization and Fc-mediated innate immune effector functions. We found that SARS-CoV-2 vaccination or infection during pregnancy increased the levels of antiviral antibodies from naïve subjects. Importantly, vaccinated mothers and cord samples had the highest anti-spike antibody levels and antiviral function independent of the time of vaccination during pregnancy. These results show that the most effective passive transfer of functional antibodies against SARS-CoV-2 in utero is achieved through vaccination, highlighting the importance of vaccination in pregnant women. Supported by grants from NIH (NCI U54CA260581-02, NHLBI Grant HL-061007) and USDA (APHIS NBAF NSTP)

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