Background: SARS-CoV-2 is a rapidly spreading disease affecting human life and the economy on a global scale. The disease has caused so far more then 5.5 million deaths. The omicron outbreak that emerged in Botswana in the south of Africa spread around the globe at further increased rates, and caused unprecedented SARS-CoV-2 infection incidences in several countries. At the start of December 2021 the first omicron cases were reported in France. Methods: In this paper we investigate the contagiousness of this novel variant relatively to the delta variant that was also in circulation in France at that time. Using a dynamic multi-variant model accounting for cross-immunity through a status-based approach, we analyze screening data reported by Sante Publique France over 13 metropolitan French regions between 1st of December 2021 and the 30th of January 2022. During the investigated period, the delta variant was replaced by omicron in all metropolitan regions in approximately three weeks. The analysis conducted retrospectively allows us to consider the whole replacement time window and compare regions with different times of omicron introduction and baseline levels of variants9 transmission potential. As large uncertainties regarding cross-immunity among variants persist, uncertainty analyses were carried out to assess its impact on our estimations. Results: Assuming that 80% of the population was immunized against delta, a cross delta/omicron cross-immunity of 25% and omicron generation time was 3.5 days, the relative strength of omicron to delta, expressed as the ratio of their respective reproduction rates, R[omicron]/R[delta], was found to range between 1.51 and 1.86 across regions. Uncertainty analysis on epidemiological parameters led to R[omicron]/R[delta] ranging over 1.57-2.13 when averaged over the metropolitan French regions, weighting by population size. Conclusions: Upon introduction, omicron spread rapidly through the French territory and showed a high fitness relative to delta. We documented considerable geographical heterogeneities on the spreading dynamics. The historical reconstruction of variant emergence dynamics provide valuable ground knowledge to face future variant emergence events.
Background: COVID-19 exhibits a steep age gradient of infection fatality rate. There has been debate about whether extra protection of elderly and other vulnerable individuals (precision shielding) is feasible, and, if so, to what extent. Methods: We used systematically retrieved data from national seroprevalence studies conducted in the pre-vaccination era. Studies were identified through SeroTracker and PubMed searches (last update May 17, 2022). Studies were eligible if they targeted representative general populations without high risk of bias. Seroprevalence estimates were noted for children, non-elderly adults, and elderly adults, using cut-offs of 20, and 60 years (or as close to these ages, if they were not available). Results: Thirty-eight national seroprevalence studies from 36 different countries were included in the analysis. 26/38 also included pediatric populations. 25/38 studies were from high-income countries. The median ratio of seroprevalence in the elderly versus non-elderly adults (or non-elderly in general, if pediatric and adult population data were not offered separately) was 0.90-0.95 in different analyses with large variability across studies. In 5 studies (all of them in high-income countries), there was significant protection of the elderly with ratio <0.40. The median was 0.83 in high-income countries and 1.02 in other countries. The median ratio of seroprevalence in children versus adults was 0.89 and only one study showed a significant ratio of <0.40. Conclusion: Precision shielding of elderly community-dwelling populations before the availability of vaccines was feasible in some high-income countries, but most countries failed to achieve any substantial focused protection of this age group.
Background. Masking serves an important role in reducing the transmission of respiratory viruses, including SARS-CoV-2. During the COVID-19 pandemic, several perspective and review articles have also argued that masking reduces the risk of developing severe disease by reducing the inoculum dose received by the contact. This hypothesis, known as the variolation hypothesis, has gained considerable traction since its development. Methods. To assess the plausibility of this hypothesis, we develop a quantitative framework for understanding the relationship between (i) inoculum dose and the risk of infection and (ii) inoculum dose and the risk of developing severe disease. We parameterize the mathematical models underlying this framework with parameters relevant for SARS-CoV-2 to quantify these relationships empirically and to gauge the range of inoculum doses in natural infections. We then identify and analyze relevant experimental studies of SARS-CoV-2 to ascertain the extent of empirical support for the proposed framework. Results. Mathematical models, when simulated under parameter values appropriate for SARS-CoV-2, indicate that the risk of infection and the risk of developing severe disease both increase with an increase in inoculum dose. However, the risk of infection increases from low to almost certain infection at low inoculum doses (with <1000 initially infected cells). In contrast, the risk of developing severe disease is only sensitive to dose at very high inoculum levels, above 106 initially infected cells. By drawing on studies that have estimated transmission bottleneck sizes of SARS-CoV-2, we find that inoculum doses are low in natural SARS-CoV-2 infections. As such, reductions in inoculum dose through masking or greater social distancing are expected to reduce the risk of infection but not the risk of developing severe disease conditional on infection. Our review of existing experimental studies support this finding. Conclusions. We find that masking and other measures such as distancing that act to reduce inoculum doses in natural infections are highly unlikely to impact the contact9s risk of developing severe disease conditional on infection. However, in support of existing empirical studies, we find that masking and other mitigation measures that reduce inoculum dose are expected to reduce the risk of infection with SARS-CoV-2. Our findings therefore undermine the plausibility of the variolation hypothesis, underscoring the need to focus on other factors such as comorbidities and host age for understanding the heterogeneity in disease outcomes for SARS-CoV-2.
Objectives: To identify factors that contribute to protection from infection with the Omicron variant of SARS-CoV-2 in older adults in nursing and retirement homes. Design: Longitudinal cohort study with retrospective analysis of infection risk. Setting and Participants: 997 residents of nursing and retirement homes from Ontario, Canada, in the COVID-in-LTC study. Methods: Residents with three mRNA dose vaccinations were included in the study. SARS-CoV-2 infection was determined by positive nasopharyngeal PCR test and/or circulating anti-nucleocapsid IgG antibodies. Cumulative probability of Omicron infection after recent COVID-19 was assessed by log-rank test of Kaplan-Meier curves. Cox regression was used to assess risk of Omicron infection by age, sex, mRNA vaccine combination, whether individuals received a fourth dose, as well as recent COVID-19. Results: 171 residents (17.2%) had a presumed Omicron variant SARS-CoV-2 infection between December 15, 2021 (local start of the first Omicron wave) and May 3, 2022. Risk of Omicron infection was not different by age [hazard ratio (95% confidence interval): 1.01 (0.99-1.02)], or in women compared to men [0.97 (0.70-1.34)], but infection risk decreased 47% with three vaccine doses of mRNA-1273 (Moderna) compared to BNT162b2 (Pfizer) [0.53 (0.31-0.90)], 81% with any fourth mRNA vaccine dose [0.19 (0.12-0.30)], and 48% with SARS-CoV-2 infection in the 3 months prior to beginning of the Omicron wave [0.52, (0.27-0.99)]. Conclusions and Implications: Vaccine type (i.e., mRNA-1273/Spikevax vs BNT162b2/Cominarty), any fourth vaccine dose, and hybrid immunity from recent COVID-19, were protective against infection with the Omicron variant. These data emphasize the importance of vaccine type, and number of vaccine doses, in maintenance of protective immunity and reduction of risk of Omicron variant breakthrough infection. These findings promote continued public health efforts to support vaccination programs and monitor vaccine immunogenicity in older adults.
In spring 2020, reduced water demand was an unintended consequence of COVID-19 pandemic-related building closures. Concerns arose that contaminants associated with water stagnation, such as Legionella pneumophila, could become prevalent. To investigate this potential public health risk, samples from 26 reduced-occupancy buildings across 11 cities in the United States, Canada, and Switzerland were analyzed for L. pneumophila using liquid culture (Legiolert, n=258) and DNA-based methods (qPCR/ddPCR, n=138). L. pneumophila culture-positivity was largely associated with just five buildings, each of which had specific design or operational deficiencies commonly associated with L. pneumophila occurrence. Samples from free chlorine buildings had higher culture-positivity (37%) than chloramine buildings (1%), and 78% of culture-positive samples occurred when the residual was ≤0.1 mg/L Cl2. Although overall sample positivities using culture- and DNA-based methods were equivalent (34% vs. 35%), there was disagreement between the methods in 13% of paired samples. Few buildings reported any water management activities, and L. pneumophila concentrations in flushed samples were occasionally greater than in first-draw samples. This study provides insight into how building plumbing characteristics and management practices contribute to L. pneumophila occurrence during low water use periods and can inform targeted prevention and mitigation efforts.
We included 852 patients in a prospectively recruiting multicenter matched case-control study in Germany to assess vaccine effectiveness (VE) in preventing COVID-19-associated hospitalization (Delta-variant dominance). Two-dose VE was 89% (95%CI 84-93%) overall, 79% in patients with >2 comorbidities and 77% in adults aged 60-75 years. A third dose increased VE to >93% in all patient-subgroups.
Background Over the course of the pandemic, testing policies for SARS-CoV-2 have varied considerably in England, particularly in the five months up to 1 April 2022 when free community testing ended. We described the trends and demographics of COVID-19 cases during this period. Methods COVID-19 cases reported between 15 November 2021 and 30 April 2022 were extracted and aggregated by testing pillar: Pillar 1 for those tested within the NHS, private or public health laboratories, and Pillar 2 for community testing. COVID-19 cases were described by epi-week, and stratified by test type, age, sex, index of multiple deprivation (IMD), region, and population density. Incidence rates were also calculated and stratified by IMD and region. Results Of 10,196,425 COVID-19 cases, 7.3% were reported under Pillar 1 and 92.7% under Pillar 2. From 15 November 2021 to 31 March 2022, most Pillar 2 cases were tested either by polymerase chain reaction (PCR) only or PCR with lateral flow device (LFD) (70.8%) and three in ten cases tested using LFD only. However, between 1 April and 30 April 2022 this rose to nine out of ten cases testing using LFD only. Over the whole period studied and under both pillars, the majority of cases were female (55.2%), resided in the South East (17.0%) and in the age group 30-39 years (18.6%). Trends in IMD and population density varied over the period. When stratifying by IMD the highest case numbers and incidence rates reported under Pillar 1 and NHS were in those in the most deprived quintile. This was also seen for cases reported under Pillar 2 by LFD until 11 January 2022, where a reverse in the trend occurred with the highest cases and rates in the least deprived quintile. This same pattern was observed when describing the cases by population density, with Pillar 2 LFD reported cases being highest in the most densely populated regions until 11 January, from when there was a switch to the highest cases being in the least densely populated regions. Conclusion Differences and trends were observed in reported COVID-19 cases in England, particularly those tested under Pillar 2 following the introduction of testing policy changes. To better understand the impact of these changes over the course of the COVID-19 pandemic, as well as to predict the impact of future testing policies, it would be beneficial to investigate the accessibility of testing amongst different populations. Currently, Pillar 1 COVID-19 cases are likely to be more representative of symptomatic cases requiring testing for a clinical need, as these are less impacted by variations in testing patterns compared to Pillar 2. However, a limitation of that approach is that use of Pillar 1 alone would be biased towards those more likely to be clinically unwell.
A large range of prognostic models for determining the risk of COVID-19 patient mortality exist, but these typically restrict the set of biomarkers considered to measurements available at patient admission. Additionally, many of these models are trained and tested on patient cohorts from a single hospital, raising questions about the generalisability of results. We used a Bayesian Markov model to analyse time series data of biomarker measurements taken throughout the duration of a COVID-19 patient9s hospitalisation for n=1540 patients from two hospitals in New York: State University of New York (SUNY) Downstate Health Sciences University and Maimonides Medical Center. In doing so, we quantified the mortality risk associated with both static (e.g. demographic and patient history variables) and dynamic factors (e.g. changes in biomarkers) throughout hospitalisation. By using our model to make predictions across the hospitals, we assessed how predictive factors generalised between the two cohorts. The individual dynamics of the measurements and their associated mortality risk were remarkably consistent across the hospitals. The model accuracy in predicting patient outcome (death or discharge) was 72.3% (predicting SUNY; posterior median accuracy) and 71.4% (predicting Maimonides) respectively. Model sensitivity was higher for detecting patients who would go on to be discharged (79.2%) versus those who died (61.0%). Our results indicate the utility of including dynamic clinical measurements when assessing patient mortality risk but also highlight the difficulty of identifying high risk patients.
Immunobridging Study of COVID-19 Protein Subunit Recombinant Vaccine - Condition: COVID-19
Interventions: Biological: COVID-19 Protein Subunit Recombinant Vaccine; Biological: Active Comparator
Sponsors: PT Bio Farma; Faculty of Medicine, Universitas Indonesia, Jakarta; Faculty of Medicine, Diponegoro University, Semarang; Faculty of Medicine, Universitas Andalas, Padang; Faculty of Medicine, Universitas Hassanudin, Makassar
Recruiting
Discussing COVID-19 Vaccines in Private Facebook Groups - Condition: COVID-19
Interventions: Behavioral: Gist messages on COVID-19 vaccination; Behavioral: COVID-19 vaccine information
Sponsor: George Washington University
Completed
A Randomized Controlled Trial of a Digital, Self-testing Strategy for COVID-19 Infection in South Africa. - Condition: COVID-19
Interventions: Device: Abbott Panbio rapid antigen self-tests; Other: COVIDSmart CARE! app
Sponsors: McGill University Health Centre/Research Institute of the McGill University Health Centre; University of Cape Town Lung Institute
Not yet recruiting
Home-Based Exercise Tele-Rehabilitation After COVID-19 - Condition: Post SARS-CoV2 (COVID-19)
Intervention: Other: Tele-exercise
Sponsors: VA Office of Research and Development; Baltimore Veterans Affairs Medical Center; Salem Veterans Affairs Medical Center
Not yet recruiting
Immunogenicity and Safety Study of One Booster Dose of Trivalent COVID-19 Vaccine (Vero Cell), Inactivated - Condition: COVID-19
Interventions: Biological: Trivalent COVID-19 Vaccine (Vero Cell), Inactivated, Prototype Strain, Delta Strain and Omicron Strain; Biological: COVID-19 Vaccine (Vero Cell), Inactivated
Sponsors: Sinovac Biotech (Colombia) S.A.S.; Sinovac Life Sciences Co., Ltd.
Not yet recruiting
IMM-BCP-01 in Mild to Moderate COVID-19 - Conditions: SARS-CoV2 Infection; COVID-19
Interventions: Drug: IMM-BCP-01; Drug: Placebo
Sponsors: Immunome, Inc.; United States Department of Defense
Recruiting
A Study to Evaluate the Safety, Tolerability, and Immunogenicity of SARS-CoV-2 Variant (COVID-19 Omicron) mRNA Vaccine (Phase 1) - Condition: COVID-19
Intervention: Biological: ABO1009-DP
Sponsor: Suzhou Abogen Biosciences Co., Ltd.
Not yet recruiting
A Study to Evaluate Safety, Tolerability, and Immunogenicity of SARS-CoV-2 Variant (COVID-19) mRNA Vaccines - Condition: COVID-19
Interventions: Biological: ABO1009-DP; Biological: ABO-CoV.617.2; Other: Placebo
Sponsor: Suzhou Abogen Biosciences Co., Ltd.
Not yet recruiting
Olfactory Training in COVID-19 Associated Loss of Smell - Conditions: COVID-19; Hyposmia
Intervention: Device: Sniffin’ sticks Duftquartett
Sponsor: Medical University Innsbruck
Not yet recruiting
Psychological Impact of Medical Evacuations on Families of Patients Admitted to Intensive Care Unit for Severe COVID-19 - Conditions: COVID-19; Stress Disorders, Post-Traumatic
Interventions: Other: Revised Impact of Event Scale; Other: Hospital Anxiety and Depression scale; Other: 36-Item Short Form Survey; Other: satisfaction survey; Other: semi-directed interview with trusted person on the general experience of the patient’s medical evacuation; Other: semi-directed interview with trusted person on the general experience of hospitalization in intensive care
Sponsor: Centre Hospitalier Metropole Savoie
Completed
Effect of COVID-19 on Platelet Mitochondrial Bioenergetic, Antioxidants and Oxidative Stress in Infertile Men. - Conditions: Infertility, Male; COVID-19
Intervention: Other: diagnostic test and sperm analysis
Sponsors: Comenius University; GYN-FIV
Active, not recruiting
Mesenchymal Stromal Cells for the Treatment of Patients With COVID-19. - Conditions: COVID-19 Pneumonia; COVID-19
Interventions: Biological: Mesenchymal stem cell; Other: Placebo
Sponsors: Paulo Brofman; Conselho Nacional de Desenvolvimento Científico e Tecnológico
Recruiting
Cardiovascular Autonomic and Immune Mechanism of Post COVID-19 Tachycardia Syndrome - Conditions: Post-acute COVID-19 Syndrome; Postural Tachycardia Syndrome (POTS); Long COVID; SARS CoV 2 Infection
Interventions: Diagnostic Test: Determine the inflammatory and immune profile of post-COVID-19 POTS patients; Diagnostic Test: Measurement of PNS activity by HRV (Heart rate Variation); Diagnostic Test: Autonomic Symptoms assessment
Sponsors: Vanderbilt University Medical Center; American Heart Association
Recruiting
A Study to Evaluate Immunogenicity and Safety of MVC-COV1901 Vaccine Compared With AZD1222 - Condition: COVID-19 Vaccine
Interventions: Biological: MVC-COV1901; Biological: AZD1222
Sponsor: Medigen Vaccine Biologics Corp.
Not yet recruiting
Study of Self-Amplifying Messenger Ribonucleic Acid (samRNA) Vaccines Against COVID-19 in Healthy Adults and People Living With Human Immunodeficiency Virus (HIV) - Conditions: COVID-19; SARS-CoV-2
Interventions: Drug: GRT-R912, samRNA-Spikebeta-TCE11; Drug: GRT-R914, samRNA-Spikebeta-TCE9; Drug: GRT-R918, samRNA-SpikeOmicron-N-TCE11
Sponsor: Gritstone bio, Inc.
Recruiting
An Overview on Immunity Booster Foods in Coronavirus Disease (COVID-19) - The present COVID-19 pandemic is highly terrible for the respiratory system and is caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). It has affected millions of people globally and over 511.9 million cases and 6.2 million deaths have been reported across the world. Various drugs have been repurposed, however, no specific medicine has been approved by the FDA to combat this disease till date. In this condition, researchers have attracted to natural and safe products to…
C910 chemical compound inhibits the traffiking of several bacterial AB toxins with cross-protection against influenza virus - The development of anti-infectives against a large range of AB-like toxin-producing bacteria includes the identification of compounds disrupting toxin transport through both the endolysosomal and retrograde pathways. Here, we performed a high-throughput screening of compounds blocking Rac1 proteasomal degradation triggered by the Cytotoxic Necrotizing Factor-1 (CNF1) toxin, which was followed by orthogonal screens against two toxins that hijack the endolysosomal (diphtheria toxin) or retrograde…
Epidemiological and virological surveillance of influenza viruses in China during 2020-2021 - CONCLUSIONS: Influenza activity increased in the mainland of China in 2021, and caused flu season in the winter of 2021-2022. Although the diversity of influenza (sub)type decreases, B/Victoria lineage viruses show increased genetic and antigenic diversity. The world needs to be fully prepared for the co-epidemic of influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus globally.
A trifunctional peptide broadly inhibits SARS-CoV-2 Delta and Omicron variants in hamsters - The emergence of highly transmissible SARS-CoV-2 variants has led to the waves of the resurgence of COVID-19 cases. Effective antivirals against variants are required. Here we demonstrate that a human-derived peptide 4H30 has broad antiviral activity against the ancestral virus and four Variants of Concern (VOCs) in vitro. Mechanistically, 4H30 can inhibit three distinct steps of the SARS-CoV-2 life cycle. Specifically, 4H30 blocks viral entry by clustering SARS-CoV-2 virions; prevents membrane…
The Zinc Proteome of SARS-CoV-2 - Zinc is an essential element for human health. Among its many functions, zinc(II) modulates the immune response to infections and, at high concentrations or in the presence of ionophores, inhibits the replication of various RNA viruses. Structural biology studies on SARS-CoV-2 revealed that zinc(II) is the most common metal ion that binds to viral proteins. However, the number of zinc(II)-binding sites identified by experimental methods is far from exhaustive, as metal ions may be lost during…
Sec61 Inhibitor Apratoxin S4 Potently Inhibits SARS-CoV-2 and Exhibits Broad-Spectrum Antiviral Activity - There is a pressing need for host-directed therapeutics that elicit broad-spectrum antiviral activities to potentially address current and future viral pandemics. Apratoxin S4 (Apra S4) is a potent Sec61 inhibitor that prevents cotranslational translocation of secretory proteins into the endoplasmic reticulum (ER), leading to anticancer and antiangiogenic activity both in vitro and in vivo. Since Sec61 has been shown to be an essential host factor for viral proteostasis, we tested Apra S4 in…
Electrospun nanofibrous membrane with antibacterial and antiviral properties decorated with Myoporum bontioides extract and silver-doped carbon nitride nanoparticles for medical masks application - Public health safety issues have been plaguing the world since the pandemic outbreak of coronavirus disease (COVID-19). However, most personal protective equipments (PPE) do not have antibacterial and anti- toxicity effects. In this work, we designed and prepared a reusable, antibacterial and anti-toxicity Polyacrylonitrile (PAN) based nanofibrous membrane cooperated with Ag/g-C(3)N(4) (Ag-CN), Myoporum.bontioides (M.bontioides) plant extracts and Ag nanoparticles (NPs) by an…
SARS-CoV-2 ORF10 antagonizes STING-dependent interferon activation and autophagy - A characteristic feature of COVID-19, the disease caused by SARS-CoV-2 infection, is the dysregulated immune response with impaired type I and III interferon (IFN) expression and an overwhelming inflammatory cytokine storm. RIG-I-like receptors (RLRs) and cGAS-STING signaling pathways are responsible for sensing viral infection and inducing IFN production to combat invading viruses. Multiple proteins of SARS-CoV-2 have been reported to modulate the RLR signaling pathways to achieve immune…
Exploring antiviral and anti-inflammatory effects of thiol drugs in COVID-19 - The redox status of the cysteine-rich SARS-CoV-2 spike glycoprotein (SARS-2-S) is important for binding of SARS-2-S to ACE2, suggesting that drugs with a functional thiol group (“thiol drugs”) may cleave cystines to disrupt SARS-CoV-2 cell entry. In addition, neutrophil-induced oxidative stress is a mechanism of COVID-19 lung injury, and the antioxidant and anti-inflammatory properties of thiol drugs, especially cysteamine, may limit this injury. To first explore antiviral effects of thiol drugs…
Targeting and Modulation of the Natriuretic Peptide System in Covid-19: A single or double-edged effect? - Natriuretic peptide system [NPS] is a group of peptide hormones or paracrine factors, including atrial natriuretic peptide [ANP], brain natriuretic peptide [BNP], and natriuretic peptide precursor C [NPC], that are structurally related. The physiological effects of NPS include natriuresis, increased glomerular filtration rate, inhibition release of renin, vasopressin, and aldosterone, sympathetic inhibition, vasodilatations, and prevents cardiac hypertrophy and remodeling. ANP has immunological…
Analysis of Interaction between odorant receptors and flexible spike of SARS CoV-2- key to loss of smell - The vaccine development for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily focused on structure of the spike (S) protein. The heavy glycosylation of S with flexible hinges at stalk shields from antibodies. The flexible nature of hinges may be one of the important factors which are responsible for binding the odorant receptor of those neurons which are responsible for the loss of smell in patients with COVID-19 infection. In this study strong and stable bond formation…
Ongoing positive selection drives the evolution of SARS-CoV-2 genomes - SARS-CoV-2 is a new RNA virus affecting humans and spreads extensively through world populations since its first outbreak in December, 2019. Whether the transmissibility and pathogenicity of SARS-CoV-2 in humans after zoonotic transfer are actively evolving, and driven by adaptation to the new host and environments is still under debate. Understanding the evolutionary mechanism underlying epidemiological and pathological characteristics of COVID-19 is essential for predicting the epidemic trend,…
Assessment of disinfectant efficacy in reducing microbial growth - The incidence of hospital- and community-acquired infections has been dramatically increased worldwide. Accordingly, hands hygiene and the use of disinfectants have been increased leading to the expansion in hand sanitizers production to meet public demand. This study was conducted to assess the efficiency of common disinfectants in the market of Riyadh, Saudi Arabia in inhibiting the microbial growth during the time of Coronavirus disease 2019 (COVID-19) pandemic. Five bacterial strains of…
Apixaban, an orally available anticoagulant, inhibits SARS-CoV-2 replication and its major protease in a non-competitive way - No abstract
An engineered 5-helix bundle derived from SARS-CoV-2 S2 pre-binds sarbecoviral spike at both serological- and endosomal-pH to inhibit virus entry - Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and related sarbecoviruses enter host cells by receptor-recognition and membrane-fusion. An indispensable step in fusion is the formation of 6-helix bundle by viral spike heptad repeats 1 and 2 (HR1 and HR2). Here, we report the construction of 5-helix bundle (5HB) proteins for virus infection inhibition. The optimal construct inhibits SARS-CoV-2 pseudovirus entry with sub-micromolar IC50. Unlike HR2-based peptides that cannot bind…