Low complexity domains of the nucleocapsid protein of SARS-CoV-2 form amyloid fibrils.

The self-assembly of the Nucleocapsid protein (NCAP) of SARS-CoV-2 is crucial for its function. Computational analysis of the amino acid sequence of NCAP reveals low-complexity domains (LCDs) akin to LCDs in other proteins known to self-assemble as phase separation droplets and amyloid fibrils. Previous reports have described NCAP's propensity to phase-separate. Here we show that the central LCD of NCAP is capable of both, phase separation and amyloid formation. Within this central LCD we identified three adhesive segments and determined the atomic structure of the fibrils formed by each. Those structures guided the design of G12, a peptide that interferes with the self-assembly of NCAP and demonstrates antiviral activity in SARS-CoV-2 infected cells. Our work, therefore, demonstrates the amyloid form of the central LCD of NCAP and suggests that amyloidogenic segments of NCAP could be targeted for drug development.

Do Socioeconomic Disparities Matter? Unraveling the Impacts of Online Vaccine Misinformation on Vaccination Intention During the COVID-19 Pandemic in China.

Concerns have been raised about whether and how groups at high risk of COVID-19 are more likely affected by online vaccine misinformation during the pandemic. This study examined the associations between exposure to online vaccine misinformation and vaccination intention through vaccination perceptions and investigated the moderating role of individuals' socioeconomic status. eHealth literacy was also investigated as a protective factor that mediated the effect of socioeconomic status. A survey of 1,700 Chinese netizens revealed that increased exposure to online COVID-19 vaccine misinformation predicted lower vaccination intention, which was mediated by negative attitudes, lowered subjective norms, lowered perceived benefits, and higher perceived barriers toward vaccination. Socio-economic status (i.e. education, income, and residence), in general, did not guarantee individuals against the negative impacts of vaccine misinformation. eHealth literacy is critical in reducing susceptibility to vaccine misinformation during the COVID-19 pandemic.

Visual detection of SARS-CoV-2 with a CRISPR/Cas12b-based platform

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, highlighting the unprecedented demand for rapid and portable diagnostic methods. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) proteins-based platforms have been used for the detection of pathogens. However, in further applications and research, due to multiple steps needed, many methods showed an increased risk of cross-reactivity. The thermostable Cas12b enables the combination of isothermal amplification and CRISPR-mediated detection, which could decrease the risk of cross-contamination. In this study, we developed a portable and specific diagnostic method that combined the gold nanoparticle (AuNP) with thermal stable CRISPR/Cas12b-enhanced reverse transcription loop-mediated isothermal amplification (RT-LAMP), which is called SCAN, to distinguish the N gene of SARS-CoV-2 from flu gene. We validated our method using RNA from cells transfected by plasmids. We could easily distinguish the positive results by the naked eye based on the strong molar absorption coefficient of AuNP. Moreover, SCAN has the potential for high-throughput tests owing to its convenient operation. In sum, SCAN has broken the site and equipment restrictions of traditional detection methods and could be applied outside of hospitals and clinical laboratories, greatly expanding the test of COVID-19. [Display omitted] • The CRISPR/Cas12 b was employed to realize one-tube detection. • The SCAN assay is isothermal that requires minimal equipment. • The SCAN assay has a high-throughput potential for large-scale population screening. [ FROM AUTHOR]

The ORF7a protein of SARS-CoV-2 initiates autophagy and limits autophagosome-lysosome fusion via degradation of SNAP29 to promote virus replication.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is closely related to various cellular aspects associated with autophagy. However, how SARS-CoV-2 mediates the subversion of the macroautophagy/autophagy pathway remains largely unclear. In this study, we demonstrate that overexpression of the SARS-CoV-2 ORF7a protein activates LC3-II and leads to the accumulation of autophagosomes in multiple cell lines, while knockdown of the viral ORF7a gene via shRNAs targeting ORF7a sgRNA during SARS-CoV-2 infection decreased autophagy levels. Mechanistically, the ORF7a protein initiates autophagy via the AKT-MTOR-ULK1-mediated pathway, but ORF7a limits the progression of autophagic flux by activating CASP3 (caspase 3) to cleave the SNAP29 protein at aspartic acid residue 30 (D30), ultimately impairing complete autophagy. Importantly, SARS-CoV-2 infection-induced accumulated autophagosomes promote progeny virus production, whereby ORF7a downregulates SNAP29, ultimately resulting in failure of autophagosome fusion with lysosomes to promote viral replication. Taken together, our study reveals a mechanism by which SARS-CoV-2 utilizes the autophagic machinery to facilitate its own propagation via ORF7a.

Futile or fertile? The effect of persuasive strategies on citizen engagement in COVID-19 vaccine-related tweets across six national health departments.

National health departments across the globe have utilized persuasive strategies to promote COVID-19 vaccines through Twitter. However, the effectiveness of those strategies is unclear. This study thereby examined how national health departments deployed persuasive strategies to promote citizen engagement in COVID-19 vaccine-related tweets in six countries, including the UK, the US, Germany, Japan, South Korea, and India. Guided by the heuristic-systematic model and the health belief model, we found that national health departments differed significantly in the use of systematic-heuristic cues and health belief constructs in COVID-19 vaccine-related tweets. Generally, the provision of scientific information and appeals to anecdotes and fear positively, while appeals to bandwagon negatively, predicted citizen engagement. Messages about overcoming barriers and promoting vaccine benefits and self-efficacy positively affected engagement. Emphases of COVID-19 threats and cues to vaccinate demonstrated negative impacts. Importantly, health departments across countries often used futile or detrimental strategies in tweets. A locally adapted evidence-based approach for COVID-19 vaccination persuasion was discussed.

The Evolution of Public Sentiments During the COVID-19 Pandemic: Case Comparisons of India, Singapore, South Korea, the United Kingdom, and the United States.

Background: Public sentiments are an important indicator of crisis response, with the need to balance exigency without adding to panic or projecting overconfidence. Given the rapid spread of the COVID-19 pandemic, governments have enacted various nationwide measures against the disease with social media platforms providing the previously unparalleled communication space for the global populations. Objective: This research aims to examine and provide a macro-level narrative of the evolution of public sentiments on social media at national levels, by comparing Twitter data from India, Singapore, South Korea, the United Kingdom, and the United States during the current pandemic. Methods: A total of 67,363,091 Twitter posts on COVID-19 from January 28, 2020, to April 28, 2021, were analyzed from the 5 countries with "wuhan," "corona," "nCov," and "covid" as search keywords. Change in sentiments ("very negative," "negative," "neutral or mixed," "positive," "very positive") were compared between countries in connection with disease milestones and public health directives. Results: Country-specific assessments show that negative sentiments were predominant across all 5 countries during the initial period of the global pandemic. However, positive sentiments encompassing hope, resilience, and support arose at differing intensities across the 5 countries, particularly in Asian countries. In the next stage of the pandemic, India, Singapore, and South Korea faced escalating waves of COVID-19 cases, resulting in negative sentiments, but positive sentiments appeared simultaneously. In contrast, although negative sentiments in the United Kingdom and the United States increased substantially after the declaration of a national public emergency, strong parallel positive sentiments were slow to surface. Conclusions: Our findings on sentiments across countries facing similar outbreak concerns suggest potential associations between government response actions both in terms of policy and communications, and public sentiment trends. Overall, a more concerted approach to government crisis communication appears to be associated with more stable and less volatile public sentiments over the evolution of the COVID-19 pandemic.

Progress of the COVID-19: Persistence, Effectiveness, and Immune Escape of the Neutralizing Antibody in Convalescent Serum.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a new coronavirus causing Coronavirus Disease 2019 (COVID-19), is a major topic of global human health concern. The Delta and Omicron variants have caused alarming responses worldwide due to their high transmission rates and a number of mutations. During a one-year follow-up (from June 2020 to June 2021), we included 114 patients with SARS-CoV-2 infection to study the long-term dynamics and the correlative factors of neutralizing antibodies (NAbs) in convalescent patients. The blood samples were collected at two detection time points (at 6 and 12 months after discharge). We evaluated the NAbs response of discharged patients by performing a micro-neutralization assay using a SARS-CoV-2 wild type. In addition, a total of 62 serum samples from discharged COVID-19 patients with Alpha, Beta, Delta, and Omicron variants of infection were enrolled to perform cross-neutralization tests using the original SARS-CoV-2 strain and VOCs variants (including Alpha, Beta, Gamma, Delta, and Omicron variants) and to assess the ability of NAbs against the SARS-CoV-2 variants. NAbs seroconversion occurred in 91.46% of patients (n = 82) in the first timepoint and in 89.29% of patients (n = 84) in the second detection point, and three kinds of NAbs kinetics curves were perceived. The NAbs levels in young patients had higher values than those in elder patients. The kinetics of disease duration was accompanied by an opposite trend in NAbs levels. Despite a declining NAbs response, NAbs activity was still detectable in a substantial proportion of recovered patients one year after discharge. Compared to the wild strain, the Omicron strain could lead to a 23.44-, 3.42-, 8.03-, and 2.57-fold reduction in neutralization capacity in "SAlpha", "SBeta", "SDelta", and "SOmicron", respectively, and the NAbs levels against the Omicron strain were significantly lower than those of the Beta and Delta variants. Remarkably, the NAbs activity of convalescent serum with Omicron strain infection was most obviously detectable against six SARS-CoV-2 strains in our study. The role of the vaccination history in NAbs levels further confirmed the previous study that reported vaccine-induced NAbs as the convincing protection mechanism against SARS-CoV-2. In conclusion, our findings highlighted the dynamics of the long-term immune responses after the disappearance of symptoms and revealed that NAbs levels varied among all types of convalescent patients with COVID-19 and that NAbs remained detectable for one year, which is reassuring in terms of protection against reinfection. Moreover, a moderate correlation between the duration of disease and Nabs titers was observed, whereas age was negatively correlated with Nabs titers. On the other hand, compared with other VOCs, the Omicron variant was able to escape the defenses of the immune system more significantly, and the convalescent serum infected with the Omicron variant played a critical part in protection against different SARS-CoV-2 variants. Recovery serum from individuals vaccinated with inactivated vaccine preceding infection with the Omicron strain had a high efficacy against the original strain and the VOCs variants, whereas the convalescent serum of persons vaccinated by inactivated vaccine prior to infection with the Delta variant was only potent against the wild-type strain.

Futile or fertile? The effect of persuasive strategies on citizen engagement in COVID-19 vaccine-related tweets across six national health departments

National health departments across the globe have utilized persuasive strategies to promote COVID-19 vaccines through Twitter. However, the effectiveness of those strategies is unclear. This study thereby examined how national health departments deployed persuasive strategies to promote citizen engagement in COVID-19 vaccine-related tweets in six countries, including the UK, the US, Germany, Japan, South Korea, and India. Guided by the heuristic-systematic model and the health belief model, we found that national health departments differed significantly in the use of systematic-heuristic cues and health belief constructs in COVID-19 vaccine-related tweets. Generally, the provision of scientific information and appeals to anecdotes and fear positively, while appeals to bandwagon negatively, predicted citizen engagement. Messages about overcoming barriers and promoting vaccine benefits and self-efficacy positively affected engagement. Emphases of COVID-19 threats and cues to vaccinate demonstrated negative impacts. Importantly, health departments across countries often used futile or detrimental strategies in tweets. A locally adapted evidence-based approach for COVID-19 vaccination persuasion was discussed.

Visual detection of SARS-CoV-2 with a CRISPR/Cas12b-based platform

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, highlighting the unprecedented demand for rapid and portable diagnostic methods. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) proteins-based platforms have been used for the detection of pathogens. However, in further applications and research, due to multiple steps needed, many methods showed an increased risk of cross-reactivity. The thermostable Cas12 b enables the combination of isothermal amplification and CRISPR-mediated detection, which could decrease the risk of cross-contamination. In this study, we developed a portable and specific diagnostic method that combined the gold nanoparticle (AuNP) with thermal stable CRISPR/Cas12 b-enhanced reverse transcription loop-mediated isothermal amplification (RT-LAMP), which is called SCAN, to distinguish the N gene of SARS-CoV-2 from flu gene. We validated our method using RNA from cells transfected by plasmids. We could easily distinguish the positive results by the naked eye based on the strong molar absorption coefficient of AuNP. Moreover, SCAN has the potential for high-throughput tests owing to its convenient operation. In sum, SCAN has broken the site and equipment restrictions of traditional detection methods and could be applied outside of hospitals and clinical laboratories, greatly expanding the test of COVID-19.

Tackling fake news in socially mediated public spheres: A comparison of Weibo and WeChat

While studies have documented the difference between political and public discussions on Chinese social media platforms, few have interrogated and compared how state and social media companies shape corresponding public spheres across different platforms. Building on research concerning socially mediated publicness, we advance the understanding of the public sphere in China as a communicative space in which the (Party-)state carries its power into society, with the platform as the structural designer and facilitator of this mediated public sphere. We further examine empirical data from the official accounts countering COVID-19 fake news on two dominant social media sites, Weibo and WeChat, between December 1, 2019 and April 30, 2020. Semantic content analysis of these posts reveals that the two social media sites showed distinctive socially mediated public spheres in terms of authoritative actors, topics and content, and media frames. The results shed light theoretically and empirically on the heterogeneity and complexity of socially mediated public spheres in Chinese cyberspace.

How News Agencies' Twitter Posts on COVID-19 Vaccines Attract Audiences' Twitter Engagement: A Content Analysis.

As the most important global news distributors, the big three international news agencies' reports about COVID-19 vaccines have a great influence on people's understanding of them. Based on the health belief model (HBM), we examined which constructs in the HBM were related to audiences' Twitter engagement and the differences among the agencies. We content-analyzed 1162 COVID-19 vaccine-related tweets from three international news agencies' Twitter accounts (@AFPespanol, @AP, @Reuters) from 2 December 2020 to 31 January 2021. The results showed that the most-used HBM construct was barriers, followed by benefits, susceptibility, cues to action, severity, and self-efficacy. About half of the tweets used a positive tone and nearly half of the tweets used a neutral tone, while only 3.1% of the tweets used a negative tone. Reuters used a significantly more negative tone, more neutral tone, and less positive tone than was expected. AFP used a significantly more positive tone and less neutral tone than was expected. The effectiveness of utilizing HBM constructs for vaccination promotion strongly depends on the audience context. The use of HBM constructs for vaccination was generally effective for Reuters but seems to have backfired for AFP.

Communication of Uncertainty about Preliminary Evidence and the Spread of Its Inferred Misinformation during the COVID-19 Pandemic-A Weibo Case Study.

The rapid spread of preliminary scientific evidence is raising concerns on its role in producing misinformation during the COVID-19 pandemic. This research investigated how the communication of uncertainty about preliminary evidence affects the spread of its inferred misinformation in a Weibo case study. In total, 3439 Weibo posts and 10,380 reposts regarding the misinformation of pets transmitting COVID-19 were analyzed. The results showed that attitude ambiguity toward the preliminary evidence and the stage when the evidence was first released with uncertainty were associated with higher numbers of likes and retweets of misinformation posts. Our study highlights the internal sources of misinformation and revisits the contextual perspective in misinformation studies.

Global sentiments surrounding the COVID-19 pandemic on Twitter

BACKGROUND: With the World Health Organization's (WHO) pandemic declaration and government-initiated actions against the disease, COVID-19 sentiments evolved rapidly. OBJECTIVE: This study examined worldwide trends of four emotions (i.e., fear, anger, sadness, and joy) and the narratives underlying those emotions during the COVID-19 pandemic. METHODS: Over 20 million social media twitter posts made during the early phases of the COVID-19 outbreak from 28 January to 9 April 2020 were collected using "wuhan", "corona", "nCov", and "covid" as search keywords. RESULTS: Public emotions shifted strongly from fear to anger over the course of the pandemic, while sadness and joy also surfaced. Findings from word clouds suggest that fears around shortages of COVID-19 tests and medical supplies became increasingly widespread discussion points. Anger shifted from xenophobia at the beginning of the pandemic to discourse around the stay-at-home notices. Sadness was highlighted by the topics of losing friends and family members while topics relating to joy included words of gratitude and good health. CONCLUSIONS: Overall, global COVID-19 sentiments have shown rapid evolutions just within the span of a few weeks. Findings suggest that emotion-driven collective issues are developing, that are entered around shared public distress experiences of the COVID-19 pandemic which include large scale social isolation and the loss of human lives. The steady rise of societal concerns indicated by negative emotions need to be monitored and controlled by complementing regular crisis communication with strategic public health communication that aims to balance public psychological wellbeing.