High-throughput detection of neutralizing antibodies to SARS-CoV-2 variants using flow cytometry (preprint)

Detecting neutralizing antibodies (NAbs) to SARS-CoV-2 variants is crucial for controlling the spread of COVID-19. In this work, we developed a high-throughput assay for the broad systematic examination of NAbs to eleven SARS-CoV variants of concern (VOCs), which include D614G, Alpha, Beta, Gamma, Delta, Kappa, and Omicron sub-lineages BA.1, BA.2, BA.3, BA.4, and BA.5. The assay is cost-effective, reliable, 35-fold more sensitive than Luminex technology, and can include the new variants during SARS-CoV-2 evolution. Importantly, our results highly correlated with a commercial IgG serological assay (R = 0.89) and cPass, a U.S. FDA-approved surrogate virus neutralization test (sVNT) assay (R = 0.93). With our high-throughput NAb platform, we constructed a comprehensive overview of the interactions between SARS-CoV-2 VOCs' Spike trimer proteins and ACE2 receptors, leading to the identification of a monoclonal Ab with broad neutralizing activity. Furthermore, when compared to the D614G variant, we found that the serum NAbs elicited by the third dose vaccine (administered after 28 days) demonstrated decreased inhibition to multiple SARS-CoV-2 variants, including Gamma (0.94x), Alpha (0.91x), Delta (0.91x), Beta (0.81x), Kappa (0.81x), BA.2 (0.44x), BA.1 (0.43x), BA.3 (0.41x), BA.5 (0.35x) and BA.4 (0.33x), in cohort of 56 vaccinated individuals. Altogether, our proteomics platform proves to be an effective tool to detect broad NAbs in the population and aid in the development of future COVID-19 vaccines and vaccination strategies.

Regional neuroinflammation caused by peripheral infection is involved in fatigued symptoms: A [18F]DPA-714 PET study (preprint)

A series of symptoms, including fever, widespread pain, fatigue, and even ageusia, have frequently been reported in the context of various infections, such as COVID-19. Although the pathogenic mechanisms underlying an infection causing fever and pain have been well established, the mechanisms of fatigue induced by infection remain unclear. To elucidate whether and how the peripheral infection cause fatigue via regional neuroinflammation, we performed a brain-wide investigation of neuroinflammation in a peripheral pseudoinfection rat model using [18F]DPA-714 positron emission tomography (PET) imaging analysis, in which the polyriboinosinic: polyribocytidylic acid (poly I:C) was intraperitoneally injected. Consistent with previous reports, transient fever lasting for several hours and subsequent suppression of spontaneous activity lasting a few days were induced by poly I:C treatment. Significant increase in plasma interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α were observed at 2 and 4 h following poly I:C treatment. PET imaging analysis revealed that the brain uptake of [18F]DPA-714 was significantly increased in several brain regions one day after poly I:C treatment, such as the dorsal raphe (DR), parvicellular part of red nucleus (RPC), A5 and A7 noradrenergic nucleus, compared with the control group. The accumulation of [18F]DPA-714 in the DR, RPC and A5 was positively correlated with the fatigue-like behavior, and that in the A7 tended to positively correlate with fever. These findings suggest that peripheral infection may trigger regional neuroinflammation, which may cause specific symptoms such as fatigue. A similar mechanism might be involved in COVID-19.

The COVID-19 shocks on the stock markets of oil exploration and production enterprises

Using daily data from January 1, 2020 to March 31, 2021, this research explores COVID-19 shocks on the stock market of 15 representative oil exploration and production enterprises from 7 countries. We measure the COVID-19 epidemic from two levels, government response stringency index and number of confirmed cases, and employ stock prices and stock market returns to reflect the stock market. Our research results confirm that both the government response stringency index and the number of confirmed cases have a significantly negative influence on stock prices. We further find that the negative reaction of the stock market to the government response stringency index is greater than that from confirmed cases. Finally, we conclude that the government response stringency index have a significantly positive effect on stock market returns of oil exploration and production enterprises. Similar findings arise from analyzing specific enterprises. Overall, our conclusions provide some useful information for the decision-making of oil exploration and production enterprises’ investors and policy makers.