Analysis of risk factors of Omicron infection and antibody response in people with HIV: a multi-center cross-sectional study (preprint)

[Purpose]Analyse the factors that influence the rate of Omicron infection, symptom severity, symptom duration and antibody levels in PLWH, in particular the role of vaccination. [Methods]We randomly investigated the Omicron infection status in 338 PLWH at multiple centers and examined their WT and Omicron specific antibodies, separately. [Results]Age was the only factor that affected the rate of Omicron infection, severity of symptoms, and duration of symptoms in PLWH. Infection, number of vaccination, ART regimen and time all affect antibody levels.With the increase of number of vaccination, both WT and BA.5 specific antibodies were gradually increased, and the overall antibody levels of PLWH with hybrid immunity were higher than those of PLWH with only vaccine immune. [Conclusions]The prevalence of Omicron is higher and symptoms is more severe in PLWH younger than 40 years, but the duration of symptoms is shorter in PLWH younger than 40 years. Although vaccination does not reduce the infection rate of SARS-CoV-2, it can significantly not only enhance the antibody level against the original strain, but also expand the antibody response against the newly emerged virus variant strain. What’s more, although breakthrough infections still occur, antibody levels can be significantly increased after hybrid immunization. For PLWH at high risk of infection, booster vaccination may be beneficial for them to cope with SARS-CoV-2 normalized infection.

Optimizing the Systematic Characteristics of Online Learning Systems to Enhance the Continuance Intention of Chinese College Students

Different from systems that directly provide online shared courses such as MOOC, online learning systems such as Tencent Classroom simulate a real classroom environment for students and teachers to realize online face-to-face teaching, utilized during the COVID-19 pandemic. Nevertheless, due to the limitation of physical distance, the intelligent design of online learning systems is necessary to provide students with a good learning experience. This study notes that an unexpected optimization effect is the impact of system characteristics on the flow experience of online learning systems, which has not been studied, but plays a vital role in the effectiveness of online learning systems. In the study, a questionnaire was created and multi-stage sampling was used to investigate 623 college students. Based on the DeLone and McLean model of IS success and flow theory, a model for optimizing system characteristics and flow experience was constructed and its effectiveness was tested. The results reveal that system characteristics have a positive impact on continuance intention and flow experience. Additionally, flow experience and learning effect have a positive impact on continuance intention. Furthermore, flow experience has a positive impact on the learning effect. This study emphasizes the flow experience of online learning systems and reveals the optimization direction of online virtual face-to-face classrooms to provide references for the Ministry of Education, schools, and enterprises providing education systems.

Innenrücktitelbild: Aptamer Blocking Strategy Inhibits SARS‐CoV‐2 Virus Infection

Eine Aptamer‐Blockierungsstrategie zur Hemmung der SARS‐CoV‐2‐Infektion wird von Honglin Chen, Yanling Song, Chaoyong Yang et al. im Forschungsartikel auf S. 10354 demonstriert. Eine Aptamer‐Sonde wurde so konstruiert, dass sie an das Spike‐Protein von SARS‐CoV‐2 bindet, was die Infektion des Virus hemmt, indem es die Interaktion des Virus mit ACE2‐Rezeptoren auf der Zellmembran blockiert.

Aptamer Blocking Strategy Inhibits SARS‐CoV‐2 Virus Infection

The COVID‐19 pandemic caused by SARS‐CoV‐2 is threating global health. Inhibiting interaction of the receptor‐binding domain of SARS‐CoV‐2 S protein (SRBD) and human ACE2 receptor is a promising treatment strategy. However, SARS‐CoV‐2 neutralizing antibodies are compromised by their risk of antibody‐dependent enhancement (ADE) and unfavorably large size for intranasal delivery. To avoid these limitations, we demonstrated an aptamer blocking strategy by engineering aptamers’ binding to the region on SRBD that directly mediates ACE2 receptor engagement, leading to block SARS‐CoV‐2 infection. With aptamer selection against SRBD and molecular docking, aptamer CoV2‐6 was identified and applied to prevent, compete with, and substitute ACE2 from binding to SRBD. CoV2‐6 was further shortened and engineered as a circular bivalent aptamer CoV2‐6C3 (cb‐CoV2‐6C3) to improve the stability, affinity, and inhibition efficacy. cb‐CoV2‐6C3 is stable in serum for more than 12 h and can be stored at room temperature for more than 14 days. Furthermore, cb‐CoV2‐6C3 binds to SRBD with high affinity (Kd=0.13 nM) and blocks authentic SARS‐CoV‐2 virus with an IC50 of 0.42 nM.

Aptamer Blocking Strategy Inhibits SARS-CoV-2 Virus Infection

Eine Aptamer-Blockierungsstrategie zur Hemmung der SARS-CoV-2-Infektion wird von Honglin Chen, Yanling Song, Chaoyong Yang et?al. in ihrem Forschungsartikel demonstriert (DOI: 10.1002/ange.202100225). Eine Aptamer-Sonde wurde so konstruiert, dass sie an das Spike-Protein von SARS-CoV-2 bindet, was die Infektion des Virus hemmt, indem es die Interaktion des Virus mit ACE2-Rezeptoren auf der Zellmembran blockiert.

Standard operating procedures for SARS-CoV-2 detection by a clinical diagnostic RT-LAMP assay (preprint)

The ongoing pandemic of SARS-CoV-2 calls for rapid and cost-effective methods to accurately identify infected individuals. The vast majority of patient samples is assessed for viral RNA presence by RT-qPCR. Our biomedical research institute, in collaboration between partner hospitals and an accredited clinical diagnostic laboratory, established a diagnostic testing pipeline that has reported on more than 40,000 RT-qPCR results since its commencement at the beginning of April 2020. However, due to ongoing demand and competition for critical resources, alternative testing strategies were sought. In this work, we present a clinically-validated standard operating procedure (SOP) for high-throughput SARS- CoV-2 detection by RT-LAMP in 25 minutes that is robust, reliable, repeatable, sensitive, specific, and inexpensive.

Scalable and Resilient SARS-CoV2 testing in an Academic Centre (preprint)

The emergence of the novel coronavirus SARS-CoV-2 has led to a pandemic infecting more than two million people worldwide in less than four months, posing a major threat to healthcare systems. This is compounded by the shortage of available tests causing numerous healthcare workers to unnecessarily self-isolate. We provide a roadmap instructing how a research institute can be repurposed in the midst of this crisis, in collaboration with partner hospitals and an established diagnostic laboratory, harnessing existing expertise in virus handling, robotics, PCR, and data science to derive a rapid, high throughput diagnostic testing pipeline for detecting SARS-CoV-2 in patients with suspected COVID-19. The pipeline is used to detect SARS-CoV-2 from combined nose-throat swabs and endotracheal secretions/ bronchoalveolar lavage fluid. Notably, it relies on a series of in-house buffers for virus inactivation and the extraction of viral RNA, thereby reducing the dependency on commercial suppliers at times of global shortage. We use a commercial RT-PCR assay, from BGI, and results are reported with a bespoke online web application that integrates with the healthcare digital system. This strategy facilitates the remote reporting of thousands of samples a day with a turnaround time of under 24 hours, universally applicable to laboratories worldwide.