The SARS-CoV-2 Antibody and Drug Research Based on the Structure of the Spike Protein and the Mechanism of Cell Entry.

COVID-19 is a severe acute respiratory syndrome caused by a novel coronavirus, SARS-CoV- 2.COVID-19 is now a pandemic, and is not yet fully under control.As the surface spike protein (S) mediates the recognition between the virus and cell membrane and the process of cell entry, it plays an important role in the course of disease transmission.The study on the S protein not only elucidates the structure and function of virus-related proteins and explains their cellular entry mechanism, but also provides valuable information for the prevention, diagnosis and treatment of COVII)-19.Concentrated on the S protein of SARS-CoV-2, this review covers four aspects: (1 ) The structure of the S protein and its binding with angiotensin converting enzyme II (ACE2) , the specific receptor of SARS-CoV-2, is introduced in detail.Compared with SARS-CoV, the receptor binding domain (RBD) of the SARS-CoV- 2 S protein has a higher affinity with ACE2, while the affinity of the entire S protein is on the contrary.(2) Currently, the cell entry mechanism of SARS-CoV-2 meditated by the S protein is proposed to include endosomal and non-endosomal pathways.With the recognition and binding between the S protein and ACE2 or after cell entry, transmembrane protease serine 2(TMPRSS2) , lysosomal cathepsin or the furin enzyme can cleave S protein at S1/S2 cleavage site, facilitating the fusion between the virus and target membrane.(3) For the progress in SARS-CoV-2 S protein antibodies, a collection of significant antibodies are introduced and compared in the fields of the target, source and type.(4) Mechanisms of therapeutic treatments for SARS-CoV-2 varied.Though the antibody and medicine treatments related to the SARS-CoV-2 S protein are of high specificity and great efficacy, the mechanism, safety, applicability and stability of some agents are still unclear and need further assessment.Therefore, to curb the pandemic, researchers in all fields need more cooperation in the development of SARS-CoV-2 antibodies and medicines to face the great challenge.Copyright © Palaeogeography (Chinese Edition).All right reserved.

Market development strategy and process performance of knowledge-intensive SMEs in the epidemic era: a process-oriented perspective

PurposeThis study analyzes in-depth how knowledge-intensive small and medium-sized enterprises (SMEs) can achieve higher new product development (NPD) process performance in the epidemic era and examine the internal development mechanism of knowledge-intensive SMEs in the process of continuous digital transformation.Design/methodology/approachThis issue is tested with partial least squares on data collected via a survey conducted from November 2021 to February 2022. The sample comprises 487 knowledge-intensive SMEs operating in China.FindingsThe results indicate that one form of cross-functional ambidexterity, market development strategy (MDS), plays an important role in process performance from an inside-out financial perspective and an outside-in customer perspective. Simultaneously, product innovation efficiency (PIE) mediates the relationship between MDS and the above results. Big data analytics capabilities (BDACs) positively regulate the relationship between MDS and PIE.Research limitations/implicationsThe authors do not consider other contingency factors. Future research should introduce influential factors such as leadership and competitive intensity to further distinguish the effects of MDS on NPD process performance.Practical implicationsThe study findings offer suggestions to help knowledge-intensive SME managers better manage their NPD process by making better use of their limited resources in developing countries such as China.Originality/valueThis study is one of only a few to adopt a process-oriented perspective to specifically examine how one form of cross-functional ambidexterity, MDS, impacts knowledge-intensive SME process performance in the epidemic era. This study also extends the theoretical framework of cross-functional ambidexterity to BDAC research.

Graph Neural Network Models for Chemical Compound Activeness Prediction For COVID-19 Drugs Discovery using Lipinski's Descriptors

In this study, we implemented graph neural network (GNN) methods to forecast in vitro inhibitory bioactivity or pharmacological concentration of chemical compounds against severe acute respiratory syndrome (SARS) coronaviruses from the graph representation amongst the compounds (i.e., nodes) and their respective features(i.e., node features) obtained by RDKit tool from their respectively SMILES (Simplified MolecularInput Line-Entry System), and we compared GNN models by experiments with our graph data of 375 nodes with 44,475 edges or links. This was done in response to the severe and significant consequences of the ongoing Coronavirus disease 2019 (COVID-19) disease. As a result, we discovered that implemented models, simple graph convolution (SGC), and graph convolution network (GCN) performed significantly well with comparable performance. © 2022 IEEE.

Gastrointestinal symptoms and disorders related to COVID-19. Lessons learned from gastroenterologists

COVID-19 is mainly a respiratory illness caused by the SARS-CoV-2 but can also lead to GI symptoms. The primary host receptor which mediates the mechanism as SARS-CoV-2 enters the cell is the ACE2 receptor. Therefore, GI symptoms can be common in COVID-19, and in some cases, they are the first manifestation even before fever and respiratory symptoms. In addition, the liver function tests alteration often is related to a worse prognosis. The exact incidence of GI symptoms is a matter of debate. Moreover, wide variation concerning GI symptoms frequency exists, but the predominant ones seem to be diarrhea, anorexia, nausea, vomiting, and abdominal pain or discomfort.This review summarizes the most relevant findings of COVID-19 on the digestive system, including the liver, biliary tract, pancreas, the most common GI symptoms, and the atypical clinical GI manifestations.Copyright © 2022 Sociedad Medica del Hospital General de Mexico. Published by Permanyer.

Perinatal SARS-CoV-2 infection and vaccination: new insight

Cumulative data regardingCOVID-19 infection during pregnancy have demonstrated the ability of SARS-CoV-2 to infect the placenta. However, the mechanisms of SARS-CoV-2 placental viral entry are yet to be defined. SARS-CoV-2 infects cells by binding to the ACE2 receptor. However, SARS-CoV-2 cell entry also requires co-localization of spike protein cleavage by the serine protease TMPRSS2. However, the co-expression of ACE2 and TMPRSS2 in placental cells is debated, raising the question of whether potential non-canonical molecular mechanismsmay be involved in SARS-CoV-2 placental cells' viral entry. Although published data regarding the ability of the SARS-CoV- 2 to infect the fetus are contradicting, the placenta appears to be an immunological barrier to active SARS-CoV-2 infection and vertical transmission;however, the mechanism is unclear. Our experiments demonstrated the ability of the SARS-CoV-2 virus to directly infect the placenta and induce transcriptomic responses in COVID-positive mothers. These transcriptomic responses were characterized by differential expression of specific mRNAs and miRNAs associated with SARS-CoV-2 infection, with induction of specific placental miRNAs that can inhibit viral replication. Failure in such mechanisms may be associated with vertical transmission. Since the start of the COVID-19 pandemic, the COVID-19 mRNA vaccines have been widely used to reduce the morbidity and mortality of SARS-CoV-2 infection. Historically, non-live vaccines have not caused any harm to pregnant mothers;however, it is unclear whether our current understanding of the effects of non-live vaccines serves as a reliable precedent owing to the novel technology used to create these mRNA vaccines. Since there are no definitive data on the possible biodistribution of mRNA vaccines to the placenta, the likelihood of vaccine mRNA reaching the fetus remains uncertain. Little has been reported on the tissue localization of the lipid nanoparticles (LNPs) after intramuscular (IM) administration of the mRNA vaccine. The biodistribution of LNPs containing the mRNA vaccine has been investigated in animal models but not humans. In the murine model, the vaccine LNPs were rapidly disseminated to several organs, including the heart, liver, kidney, lung, and spleen, following IM administration. However, no traditional pharmacokinetic or biodistribution studies have been performed with the mRNA vaccines, including possible biodistribution to breast milk or the placenta.

The Pandemic and Free Movement of Workers: Two Challenges in Austrian Practice

Covid-19 has brought unprecedented restrictions on the free movement of workers. This paper takes a critical look at entry restrictions related to testing, vaccination and recovery. In addition, Covid-19, in combination with the entry restrictions, has led to an increase in cross-border working from home, which may result in changes to the applicable labour law. © 2023 Kluwer Law International BV, The Netherland

A resource of human coronavirus protein-coding sequences in a flexible, multipurpose Gateway Entry clone collection.

The COVID-19 pandemic has catalyzed unprecedented scientific data and reagent sharing and collaboration, which enabled understanding the virology of the SARS-CoV-2 virus and vaccine development at record speed. The pandemic, however, has also raised awareness of the danger posed by the family of coronaviruses, of which 7 are known to infect humans and dozens have been identified in reservoir species, such as bats, rodents, or livestock. To facilitate understanding the commonalities and specifics of coronavirus infections and aspects of viral biology that determine their level of lethality to the human host, we have generated a collection of freely available clones encoding nearly all human coronavirus proteins known to date. We hope that this flexible, Gateway-compatible vector collection will encourage further research into the interactions of coronaviruses with their human host, to increase preparedness for future zoonotic viral outbreaks.

Chestnut inner shell extract inhibits viral entry of porcine epidemic diarrhea virus and other coronaviruses in vitro.

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes acute diarrhea in suckling piglets. Although vaccines are able to reduce the incidence of PEDV infection, outbreaks of PEDV continue to be reported worldwide and cause serious economic losses in the swine industry. To identify novel antiviral sources, we identified the chestnut (Castanea crenata) inner shell (CIS) as a natural material with activity against PEDV infection in vitro. The ethanol fractions of CIS extracts potently inhibited PEDV infection with an IC90 of 30 µg/ml. Further investigation of the virus lifecycle demonstrated that CIS extract particularly targeted the early stages of PEDV infection by blocking viral attachment and membrane fusion at rates of 80~90%. In addition, CIS extract addition reduced the viral entry of other members of the Coronaviridae family. Our data demonstrated that CIS extract inhibited PEDV infection by blocking cell entry in vitro and suggest that CIS extract is a new prophylactic and therapeutic agent against PEDV and other coronavirus infections.

Preferences and values for government policies on infectious disease outbreaks and epidemics for the Japanese population: a conjoint analysis.

AIMS: To investigate the preferences of the Japanese population for government policies expected to address infectious disease outbreaks and epidemics. METHODS: We performed a conjoint analysis based on survey data in December 2022 (registration number: UMIN000049665). The attributes for the conjoint analysis were policies: tests, vaccines, therapeutic drugs, behavior restrictions (e.g. self-restraint or restrictions on the gathering or travel of individuals and the hours of operation or serving of alcoholic beverages in food/beverage establishments), and entry restrictions (from abroad), and monetary attribute: an increase in the consumption tax from the current 10%, to estimate the monetary value of the policies. A logistic regression model was used for the analysis. RESULTS: Data were collected from 2,185 respondents. The accessibility of tests, vaccines, and therapeutic drugs was preferred regardless of the accessibility level. The value for accessibility of drugs to anyone at any medical facility was estimated at 4.80% of a consumption tax rate, equivalent to JPY 10.5 trillion, which was the highest among the policies evaluated in this study. The values for implementing behavior or entry restrictions were negative or lower than those for tests, vaccines, and drugs. LIMITATIONS: Respondents chosen from an online panel were not necessarily representative of the Japanese population. Because the study was conducted in December 2022, a period during the coronavirus disease 2019 (COVID-19) pandemic, the results may reflect the situation at that time and potentially be subject to rapid change. CONCLUSIONS: Among the policy options evaluated in this study, the most preferred option was easily accessible therapeutic drugs and their monetary value was substantial. Wider accessibility of tests, vaccines, and drugs was preferred over behavior and entry restrictions. We believe that the results provide information for policymaking to prepare for future infectious disease epidemics and for assessing the response to COVID-19 in Japan.

DHFR Inhibitors Display a Pleiotropic Anti-Viral Activity against SARS-CoV-2: Insights into the Mechanisms of Action.

During the COVID-19 pandemic, drug repurposing represented an effective strategy to obtain quick answers to medical emergencies. Based on previous data on methotrexate (MTX), we evaluated the anti-viral activity of several DHFR inhibitors in two cell lines. We observed that this class of compounds showed a significant influence on the virus-induced cytopathic effect (CPE) partly attributed to the intrinsic anti-metabolic activity of these drugs, but also to a specific anti-viral function. To elucidate the molecular mechanisms, we took advantage of our EXSCALATE platform for in-silico molecular modelling and further validated the influence of these inhibitors on nsp13 and viral entry. Interestingly, pralatrexate and trimetrexate showed superior effects in counteracting the viral infection compared to other DHFR inhibitors. Our results indicate that their higher activity is due to their polypharmacological and pleiotropic profile. These compounds can thus potentially give a clinical advantage in the management of SARS-CoV-2 infection in patients already treated with this class of drugs.

In Silico and In Vitro Evaluation of Some Amidine Derivatives as Hit Compounds towards Development of Inhibitors against Coronavirus Diseases.

Coronaviruses, including SARS-CoV-2, SARS-CoV, MERS-CoV and influenza A virus, require the host proteases to mediate viral entry into cells. Rather than targeting the continuously mutating viral proteins, targeting the conserved host-based entry mechanism could offer advantages. Nafamostat and camostat were discovered as covalent inhibitors of TMPRSS2 protease involved in viral entry. To circumvent their limitations, a reversible inhibitor might be required. Considering nafamostat structure and using pentamidine as a starting point, a small set of structurally diverse rigid analogues were designed and evaluated in silico to guide selection of compounds to be prepared for biological evaluation. Based on the results of in silico study, six compounds were prepared and evaluated in vitro. At the enzyme level, compounds 10-12 triggered potential TMPRSS2 inhibition with low micromolar IC50 concentrations, but they were less effective in cellular assays. Meanwhile, compound 14 did not trigger potential TMPRSS2 inhibition at the enzyme level, but it showed potential cellular activity regarding inhibition of membrane fusion with a low micromolar IC50 value of 10.87 µM, suggesting its action could be mediated by another molecular target. Furthermore, in vitro evaluation showed that compound 14 inhibited pseudovirus entry as well as thrombin and factor Xa. Together, this study presents compound 14 as a hit compound that might serve as a starting point for developing potential viral entry inhibitors with possible application against coronaviruses.

Points of entry dynamics: understanding the cross-border threats for Ebola virus disease and COVID-19 in Ghana using a logic model approach.

Background: The influx of people across the national borders of Ghana has been of interest and concern in the public health and national security community in recent times due to the low capacity for the prevention and management of epidemics and other public health risks. Although the international health regulations (IHR) stipulate core public health capacities for designated border facilities such as international airports, seaports, and ground crossings, contextual factors that influence the attainment of effective public health measures and response capabilities remain understudied. Objective: This study aims to assess the relationship between contextual factors and COVID-19 procurement to help strengthen infrastructure resources for points of entry (PoE) public health surveillance functions, thereby eliminating gaps in the design, implementation, monitoring, and evaluation of pandemic-related interventions in Ghana. Methods: This study employed a mixed-methods design, where quantitative variables were examined for relationships and effect size interactions using multiple linear regression techniques and the wild bootstrap technique. Country-level data was sourced from multiple publicly available sources using the social-ecological framework, logic model, and IHR capacity monitoring framework. The qualitative portion included triangulation with an expert panel to determine areas of convergence and divergence. Results: The most general findings were that laboratory capacity and Kotoka International Airport testing center positively predicted COVID-19 procurement, and public health response and airline boarding rule negatively predicted COVID-19 procurement. Conclusion: Contextual understanding of the COVID-19 pandemic and Ebola epidemic is vital for strengthening PoE mitigation measures and preventing disease importation.

Identification of small molecules capable of enhancing viral membrane fusion.

Several approaches have been developed to analyze the entry of highly pathogenic viruses. In this study, we report the implementation of a Bimolecular Multicellular Complementation (BiMuC) assay to safely and efficiently monitor SARS-CoV-2 S-mediated membrane fusion without the need for microscopy-based equipment. Using BiMuC, we screened a library of approved drugs and identified compounds that enhance S protein-mediated cell-cell membrane fusion. Among them, ethynylestradiol promotes the growth of SARS-CoV-2 and Influenza A virus in vitro. Our findings demonstrate the potential of BiMuC for identifying small molecules that modulate the life cycle of enveloped viruses, including SARS-CoV-2.

Women's self-employment intentions after global shocks: insights from Egypt and Spain

We compare the self-employment intentions of women from different contexts, namely, Egypt and Spain after two recent incidents of global economic collapse - the 2008 global financial crisis and the COVID-19 pandemic. We draw on occupational choice and human capital theories to better understand how the self-employment intentions of women with different age, perceptual and human capital profiles vary in periods of crisis. Consistent with previous studies, the results suggest that intentions of self-employment vary with the specific perceptual and human capital attributes of women. However, the macroeconomic conditions and the context matter since the findings also show that the factors that drive the self-employment intention of women differ from one global shock to another. Moreover, the impact of each global shock in every context is different. These findings provide new guidance for policymakers by acknowledging the relevance of the heterogeneity of women, economic periods and contexts to the choice of self-employment.

Maintaining Cross-Border Cargo Movements Between Jordan and Saudi Arabia During the COVID-19 Pandemic

One of Jordan's essential border crossings, the Al-Omari border crossing, is 1 of 3 land crossings between Jordan and Saudi Arabia and is located 160 km west of the capital city of Amman. Given its economic importance and essential role in the functioning of food supply networks across the region, Jordan undertook evidence-driven actions to keep the border crossing safely open during the initial phase of the COVID-19 pandemic. Cross-border coordination and collaboration, specifically with international contact tracing and case management, have been critical elements of Jordan's response. While several bottlenecks and delays led to documented clusters of infections among truck drivers, this case study illustrates the use of evidence to mitigate disease exposure and spread. Plans to manage public health threats need to consider sustainable strengthened surveillance and laboratory capacities coupled with efficient cross-border communication and coordination plans implemented across multiple sectors engaged in cross-country health.

Metformin in COVID-19: Is There a Role Beyond Glycemic Control?

Context: The coronavirus disease 2019 (COVID-19) pandemic is still a cause of worldwide health concern. Diabetes and its associated comorbidities are risk factors for mortality and morbidity in COVID-19. Selecting the right antidiabetic drug to achieve optimal glycemic control might mitigate some of the negative impacts of diabetes. Metformin continues to be the most widely administered antidiabetic agent. There is evidence of its beneficial outcome in COVID-19 independent of its glucose-lowering effect. Evidence Acquisition: A thorough literature search was conducted in PubMed, Google Scholar, Scopus, and Web of Science to identify studies investigating metformin in COVID-19. Result(s): Several overlapping mechanisms have been proposed to explain its antiviral properties. It could bring about conformational changes in the angiotensin-converting enzyme-2 receptor and decrease viral entry. The effects on the mammalian target of the rapamycin pathway and cellular pH have been proposed to reduce viral protein synthesis and replication. The immunomodulatory effects of metformin might counter the detrimental effects of hyperinflammation associated with COVID-19. Conclusion(s): These findings call for broader metformin usage to manage hyperglycemia in COVID-19.Copyright © 2023, International Journal of Endocrinology and Metabolism.

Business dynamism, sectoral reallocation and productivity in a pandemic.

Asymmetric effects across sectors are the distinctive features of the Covid-19 shock. An Epidemiological-Industry Dynamic model with heterogeneous firms and endogenous firms dynamics mimics the deep recession suffered by sectors characterized by high exposure, the reallocation of entry and exit opportunities across sectors, and the dynamics of aggregate productivity during the first wave of the pandemic. The cleansing effect induced by the Covid-19 crisis is sector-specific. Monetary policy and sticky wages are central ingredients to capture reallocation effects. Social distancing, by smoothing out cleansing in the social sector, slows down the reallocation process and prolongs the recession, but saves lives.

Human Adenovirus Type 26 Infection Mediated by αvß3 Integrin Is Caveolin-1-Dependent.

Human adenovirus type 26 (HAdV26) has been recognized as a promising platform for vaccine vector development, and very recently vaccine against COVID-19 based on HAdV26 was authorized for emergency use. Nevertheless, basic biology of this virus, namely, pathway which HAdV26 uses to enter the cell, is still insufficiently known. We have shown here that HAdV26 infection of human epithelial cells expressing low amount of αvß3 integrin involves clathrin and is caveolin-1-independent, while HAdV26 infection of cells with high amount of αvß3 integrin does not involve clathrin but is caveolin-1-dependent. Thus, this study demonstrates that caveolin-1 is limiting factor in αvß3 integrin-mediated HAdV26 infection. Regardless of αvß3 integrin expression, HAdV26 infection involves dynamin-2. Our data provide for the first-time description of HAdV26 cell entry pathway, hence increase our knowledge of HAdV26 infection. Knowing that functionality of adenovirus vector is influenced by its cell entry pathway and intracellular trafficking, our results will contribute to better understanding of HAdV26 immunogenicity and antigen presentation when used as vaccine vector. IMPORTANCE In order to fulfill its role as a vector, adenovirus needs to successfully deliver its DNA genome to the host nucleus, a process highly influenced by adenovirus intracellular translocation. Thus, cell entry pathway and intracellular trafficking determine functionality of human adenovirus-based vectors. Endocytosis of HAdV26, currently extensively studied as a vaccine vector, has not been described so far. We present here that HAdV26 infection of human epithelial cells with high expression of αvß3 integrin, one of the putative HAdV26 receptors, is caveolin-1- and partially dynamin-2-dependent. Since caveolin containing domains provide a unique environment for specific signaling events and participate in inflammatory signaling one can imagine that directing HAdV26 cell entry toward caveolin-1-mediate pathway might play role in immunogenicity of this virus. Therefore, our results contribute to better understanding of HAdV26 infection pathway, hence, can be helpful in explaining induction of immune response and antigen presentation by HAdV26-based vaccine vector.

Estimating the effects of legalizing drug e-commerce

With the technological development the e-commerce channel began to spread to all sectors of the economy. In 2020 with the introduction of sanitary and epidemiological restrictions because of COVID-19 pandemic, many countries lifted the ban of drug e-commerce. Such changes are interesting from the point of view of health economics, and the opening of this sales channel significantly reduces transaction costs and increases the physical availability of drugs, especially in regions with low population density. The article attempts to evaluate the effects of legalization of online sales of drugs on price level and the degree of market concentration (the concentration of the 5 largest companies is used as a proxy), and also uses new methods to estimate the effects of legalizing e-commerce on drug markets. High rates of industry and drug market concentration can lead to a noticeable decrease in the availability of goods. Legalizing e-commerce can be seen as a way to reduce market concentration by facilitating market entry for small firms. The effects of lifting the ban on remote drug sales are estimated using regression analysis on panel data, cross-country matching, and synthetic control. Empirical estimates provide an overall picture of the effects of legalizing online drug sales. After allowing remote drug sales market concentration decreases, indicating a reduction in information asymmetry and switching costs. This effect is particularly important for countries with a high proportion of pensioners, for whom the switching costs are noticeably higher ceteris paribus. Allowing distance trade, due to reducing information asymmetry, drug pricing also slows down, that is, in addition to increasing physical accessibility, opening this channel also increases economic accessibility.

OMICRON SPIKE ENDOWS SARS-CoV-2 WITH ENHANCED INFECTIVITY IN NASAL EPITHELIA

Background: Omicron lineages, including BA.1 and BA.2, emerged following mass COVID-19 vaccination campaigns, displaced previous SARS-CoV-2 variants of concern worldwide, and gave rise to sublineages that continue to spread among humans. Previous research has shown that Omicron lineages exhibit a decreased propensity for lower respiratory tract (lung) infection compared to ancestral SARS-CoV-2, which may explain the decreased pathogenicity associated with Omicron infections. Nonetheless, Omicron lineages exhibit an unprecedented transmissibility in humans, which until now has been solely attributed to escape from vaccine-induced neutralizing antibodies. Method(s): We comprehensively analyzed BA1 and BA2 infection in primary human nasal epithelial cells cultured at the air-liquid interface, which recapitulates the physiological architecture of the nasal epithelium in vivo. Meanwhile we also took advantage of the VSV-based pseudovirus decorated with different Spike variants. Result(s): In primary human nasal epithelial cells cultured at the air-liquid interface, which recapitulates the physiological architecture of the nasal epithelium in vivo, BA.1 and BA.2 exhibited enhanced infectivity relative to ancestral SARS-CoV-2. Using VSV-based pseudovirus decorated with different Spike variants, we found that increased infectivity conferred by Omicron Spike is due to superior attachment and entry into nasal epithelial cells. In contrast to ancestral SARS-CoV-2, invasion of nasal epithelia by Omicron occurred via the cell surface and endosomal routes of entry and was accompanied by elevated induction of type-I interferons, indicative of a robust innate immune response. Furthermore, BA.1 was less sensitive to inhibition by the antiviral state elicited by type-I and type-III interferons, and this was recapitulated by pseudovirus bearing BA.1 and BA.2 Spike proteins. Conclusion(s): Our results suggest that the constellation of Spike mutations unique to Omicron allow for increased adherence to nasal epithelia, flexible usage of virus entry pathways, and interferon resistance. These findings inform our understanding of how Omicron evolved elevated transmissibility between humans despite a decreased propensity to infect the lower respiratory tract. Additionally, the interferon insensitivity of the Omicron Spike-mediated entry process may explain why Omicron lineages lost the capacity to antagonize interferon pathways compared to ancestral SARS-CoV-2.