Omicron - The new SARS-CoV-2 challenge?

Evolution of the SARS-CoV-2 Omicron Variants: Genetic Impact on Viral Fitness

Over the last three years, the pandemic of COVID-19 has had a significant impact on people's lives and the global economy. The incessant emergence of variant strains has compounded the challenges associated with the management of COVID-19. As the predominant variant from late 2021 to the present, Omicron and its sublineages, through continuous evolution, have demonstrated iterative viral fitness. The comprehensive elucidation of the biological implications that catalyzed this evolution remains incomplete. In accordance with extant research evidence, we provide a comprehensive review of subvariants of Omicron, delineating alterations in immune evasion, cellular infectivity, and the cross-species transmission potential. This review seeks to clarify the underpinnings of biology within the evolution of SARS-CoV-2, thereby providing a foundation for strategic considerations in the post-pandemic era of COVID-19.

Suramin inhibits SARS-CoV-2 nucleocapsid phosphoprotein genome packaging function

The coronavirus disease 2019 (COVID-19) pandemic is fading, however its etiologic agent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues posing - despite the availability of licensed vaccines - a global health threat, due to the potential emergence of vaccine-resistant SARS-CoV-2 variants. This makes the development of new drugs against COVID-19 a persistent urgency and sets as research priority the validation of novel therapeutic targets within the SARS-CoV-2 proteome. Among these, a promising one is the SARS-CoV-2 nucleocapsid (N) phosphoprotein, a major structural component of the virion with indispensable role in packaging the viral genome into a ribonucleoprotein (RNP) complex, which also contributes to SARS-CoV-2 innate immune evasion by inhibiting the host cell type-I interferon (IFN-I) response. By combining miniaturized differential scanning fluorimetry with microscale thermophoresis, we found that the 100-year-old drug Suramin interacts with SARS-CoV-2 N-terminal domain (NTD) and C-terminal domain (CTD), thereby inhibiting their single-stranded RNA (ssRNA) binding function with low-micromolar Kd and IC50 values. Molecular docking suggests that Suramin interacts with basic NTD cleft and CTD dimer interface groove, highlighting three potentially druggable ssRNA binding sites. Electron microscopy shows that Suramin inhibits the formation in vitro of RNP complex-like condensates by SARS-CoV-2 N with a synthetic ssRNA. In a dose-dependent manner, Suramin also reduced SARS-CoV-2-induced cytopathic effect on Vero E6 and Calu-3 cells, partially reverting the SARS-CoV-2 N-inhibited IFN-I production in 293T cells. Our findings indicate that Suramin inhibits SARS-CoV-2 replication by hampering viral genome packaging, thereby representing a starting model for design of new COVID-19 antivirals.

Primary Series and Booster Coronavirus Disease 2019 Vaccine Effectiveness in a Cohort of Healthcare Workers in Albania During a BA.1 and BA.2 Variant Period, January-May 2022

Background

Healthcare workers (HCWs) have experienced high rates of coronavirus disease 2019 (COVID-19) morbidity and mortality. We estimated COVID-19 2-dose primary series and monovalent booster vaccine effectiveness (VE) against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (BA.1 and BA.2) infection among HCWs in 3 Albanian hospitals during January-May 2022.

Methods

Study participants completed weekly symptom questionnaires, underwent polymerase chain reaction (PCR) testing when symptomatic, and provided quarterly blood samples for serology. We estimated VE using Cox regression models (1 - hazard ratio), with vaccination status as the time-varying exposure and unvaccinated HCWs as the reference group, adjusting for potential confounders: age, sex, prior SARS-CoV-2 infection (detected by PCR, rapid antigen test, or serology), and household size.

Results

At the start of the analysis period, 76% of 1462 HCWs had received a primary series, 10% had received a booster dose, and 9% were unvaccinated; 1307 (89%) HCWs had evidence of prior infection. Overall, 86% of primary series and 98% of booster doses received were BNT162b2. The median time interval from the second dose and the booster dose to the start of the analysis period was 289 (interquartile range [IQR], 210-292) days and 30 (IQR, 22-46) days, respectively. VE against symptomatic PCR-confirmed infection was 34% (95% confidence interval [CI], -36% to 68%) for the primary series and 88% (95% CI, 39%-98%) for the booster.

Conclusions

Among Albanian HCWs, most of whom had been previously infected, COVID-19 booster dose offered improved VE during a period of Omicron BA.1 and BA.2 circulation. Our findings support promoting booster dose uptake among Albanian HCWs, which, as of January 2023, was only 20%. Clinical Trials Registration. NCT04811391.

"Nano COVID-19": Nanopore sequencing of spike gene to identify SARS-CoV-2 variants of concern

Coronavirus disease 2019 (COVID-19) is a worldwide pandemic infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). World Health Organization (WHO) has defined the viral variants of concern (VOC) which cause more severe disease, higher transmissibility, and reduced vaccine efficacy. In this study, the "Nano COVID-19" workflow based on Oxford nanopore sequencing of the full-length spike gene combined with flexible data analysis options was developed to identify SARS-CoV-2 VOCs. The primers were designed to cover the full-length spike gene and can amplify all VOC strains. The results of VOC identification based on phylogenetic analysis of the full-length spike gene were comparable to the whole genome sequencing (WGS). Compared to the standard VOC identification pipeline, the fast analysis based on Read Assignment, Mapping, and Phylogenetic Analysis in Real Time (RAMPART) and the user-friendly method based on EPI2ME yielded 89.3% and 97.3% accuracy, respectively. The EPI2ME pipeline is recommended for researchers without bioinformatic skills, whereas RAMPART is more suitable for bioinformaticians. This workflow provides a cost-effective, simplified pipeline with a rapid turnaround time. Furthermore, it is portable to point-of-care SARS-CoV-2 VOC identification and compatible with large-scale analysis. Therefore, "Nano COVID-19" is an alternative viral epidemic screening and transmission tracking workflow.

Viral target and metabolism-based rationale for combined use of recently authorized small molecule COVID-19 medicines: Molnupiravir, nirmatrelvir, and remdesivir

The COVID-19 pandemic remains a major health concern worldwide, and SARS-CoV-2 is continuously evolving. There is an urgent need to identify new antiviral drugs and develop novel therapeutic strategies. Combined use of newly authorized COVID-19 medicines including molnupiravir, nirmatrelvir, and remdesivir has been actively pursued. Mechanistically, nirmatrelvir inhibits SARS-CoV-2 replication by targeting the viral main protease (Mpro ), a critical enzyme in the processing of the immediately translated coronavirus polyproteins for viral replication. Molnupiravir and remdesivir, on the other hand, inhibit SARS-CoV-2 replication by targeting RNA-dependent RNA-polymerase (RdRp), which is directly responsible for genome replication and production of subgenomic RNAs. Molnupiravir targets RdRp and induces severe viral RNA mutations (genome), commonly referred to as error catastrophe. Remdesivir, in contrast, targets RdRp and causes chain termination and arrests RNA synthesis of the viral genome. In addition, all three medicines undergo extensive metabolism with strong therapeutic significance. Molnupiravir is hydrolytically activated by carboxylesterase-2 (CES2), nirmatrelvir is inactivated by cytochrome P450-based oxidation (e.g., CYP3A4), and remdesivir is hydrolytically activated by CES1 but covalently inhibits CES2. Additionally, remdesivir and nirmatrelvir are oxidized by the same CYP enzymes. The distinct mechanisms of action provide strong rationale for their combined use. On the other hand, these drugs undergo extensive metabolism that determines their therapeutic potential. This review discusses how metabolism pathways and enzymes involved should be carefully considered during their combined use for therapeutic synergy.

The effects of amino acid substitution of spike protein and genomic recombination on the evolution of SARS-CoV-2

Over three years' pandemic of 2019 novel coronavirus disease (COVID-19), multiple variants and novel subvariants have emerged successively, outcompeted earlier variants and become predominant. The sequential emergence of variants reflects the evolutionary process of mutation-selection-adaption of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Amino acid substitution/insertion/deletion in the spike protein causes altered viral antigenicity, transmissibility, and pathogenicity of SARS-CoV-2. Early in the pandemic, D614G mutation conferred virus with advantages over previous variants and increased transmissibility, and it also laid a conservative background for subsequent substantial mutations. The role of genomic recombination in the evolution of SARS-CoV-2 raised increasing concern with the occurrence of novel recombinants such as Deltacron, XBB.1.5, XBB.1.9.1, and XBB.1.16 in the late phase of pandemic. Co-circulation of different variants and co-infection in immunocompromised patients accelerate the emergence of recombinants. Surveillance for SARS-CoV-2 genomic variations, particularly spike protein mutation and recombination, is essential to identify ongoing changes in the viral genome and antigenic epitopes and thus leads to the development of new vaccine strategies and interventions.

SARS-CoV2 mutations and impact on mortality: observational study in a sub-saharan Africa hospital

BACKGROUND

One year after the coronavirus disease 2019 (COVID-19) pandemic, the focus of attention has shifted to the emergence and spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants of concern (VOCs). The aim of the study was to assess the frequency of VOCs in patients followed for COVID-19 at Kinshasa university hospital (KUH) during the 3rd and 4th waves of the pandemic in Kinshasa. Hospital mortality was compared to that of the first two waves.

METHOD

The present study included all patients in whom the diagnosis of SARS-CoV-2 infection was confirmed by the polymerase chain reaction (PCR). The laboratory team sequenced a subset of all SARS-CoV-2 positive samples with high viral loads define as Ct < 25 to ensure the chances to generate complete genome sequence. RNA extraction was performed using the Viral RNA Mini Kit (Qiagen). Depending on the platform, we used the iVar bioinformatics or artic environments to generate consensus genomes from the raw sequencing output in FASTQ format.

RESULTS

During the study period, the original strain of the virus was no longer circulating. The Delta VOC was predominant from June (92%) until November 2021 (3rd wave). The Omicron VOC, which appeared in December 2021, became largely predominant one month later (96%) corresponding the 4th wave. In-hospital mortality associated with COVID-19 fell during the 2nd wave (7% vs. 21% 1st wave), had risen during the 3rd (16%) wave before falling again during the 4th wave (7%) (p < 0.001).

CONCLUSION

The Delta (during the 3rd wave) and Omicron VOCs (during the 4th wave) were very predominant among patients followed for Covid-19 in our hospital. Contrary to data in the general population, hospital mortality associated with severe and critical forms of COVID-19 had increased during the 3rd wave of the pandemic in Kinshasa.

COVID-19 Screening in the Pediatric Emergency Department

BACKGROUND

Screening for COVID-19 infection in pediatrics is challenging as its clinical presentation may be asymptomatic or mimic other common childhood infections. We examined the use of a COVID-19 screening protocol (CSP) in the pediatric emergency department (PED) to determine the incidence of positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) tests in patients who are CSP+ and CSP-.

METHODS

We conducted a retrospective cohort study of pediatric patients with SARS-CoV-2 testing completed in an urban tertiary care PED from November 1 to December 31, 2020. Demographics, CSP designation, test results, and disposition were compared. Statistical significance was determined using chi-square or a comparison of means. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) with 95% confidence intervals (CI) were calculated.

RESULTS

A total of 1,613 patients had SARS-CoV-2 tests completed with 9.1% (N=147) having positive test results. Of 1,014 (62.9%) patients who were CSP+, 12.9% tested positive. Comparatively, 599 (37.1%) patients were CSP- with only 2.7% positive tests, p<0.0001. The sensitivity, specificity, NPV, and PPV of the CSP in all tested patients were 89.1%, 39.8%, 97.3%, and 12.9%, respectively. Of tested patients, 887 (55.0%) were admitted to the hospital and were more likely to be positive if CSP+, p≤0.001. Within the admitted group, 16.8% were admitted to the operating room, of whom 83.9% were CSP- with 4.0% testing positive for SARS-CoV-2.

CONCLUSIONS

COVID-19 screening in the pediatric population is a useful modality to risk stratify most patients presenting to the PED for the purpose of selective testing and guiding personal protective equipment use. This may be particularly useful in low-resource settings.

Fatal cases after Omicron BA.1 and BA.2 infection: Results of an autopsy study

OBJECTIVES

Omicron lineages BA.1/2 are considered to cause mild clinical courses. Nevertheless, fatal cases after those infections are recognized but little is known about risk factors.

METHODS

A total of 23 full and three partial autopsies in deceased with known Omicron BA.1/2 infections have been consecutively performed. The investigations included histology, blood analyses, and molecular virus detection.

RESULTS

COVID-19-associated diffuse alveolar damage was found in only eight cases (31%). This rate is significantly lower compared with previous studies, including non-Omicron variants, where rates between 69% and 92% were observed. Neither vaccination nor known risk factors were significantly associated with a direct cause of death by COVID-19. Only those patients who were admitted to the clinic because of COVID-19 but not for other reasons had a significant association with a direct COVID-19 -caused death (P >0.001).

CONCLUSION

Diffuse alveolar damage still occurred in the Omicron BA.1/BA.2 era but at a considerably lower frequency than seen with previous variants of concern. None of the known risk factors discriminated the cases with COVID-19-caused death from those that died because of a different disease. Therefore, the host's genomics might play a key role in this regard. Further studies should elucidate the existence of such a genomic risk factor.

A novel, ultrafast, ultrasensitive diagnosis platform for the detection of SARS-COV-2 using restriction endonuclease-mediated reverse transcription multiple cross displacement amplification

Coronavirus disease 2019 (COVID-19) is a highly infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). Though many methods have been used for detecting SARS-COV-2, development of an ultrafast and highly sensitive detection strategy to screen and/or diagnose suspected cases in the population, especially early-stage patients with low viral load, is significant for the prevention and treatment of COVID-19. In this study, a novel restriction endonuclease-mediated reverse transcription multiple cross displacement amplification (MCDA) combined with real-time fluorescence analysis (rRT-MCDA) was successfully established and performed to diagnose COVID-19 infection (COVID-19 rRT-MCDA). Two sets of specific SARS-COV-2 rRT-MCDA primers targeting opening reading frame 1a/b (ORF1ab) and nucleoprotein (NP) genes were designed and modified according to the reaction mechanism. The SARS-COV-2 rRT-MCDA test was optimized and evaluated using various pathogens and clinical samples. The optimal reaction condition of SARS-COV-2 rRT-MCDA assay was 65°C for 36 min. The SARS-COV-2 rRT-MCDA limit of detection (LoD) was 6.8 copies per reaction. Meanwhile, the specificity of SARS-COV-2 rRT-MCDA assay was 100%, and there was no cross-reaction with nucleic acids of other pathogens. In addition, the whole detection process of SARS-COV-2 rRT-MCDA, containing the RNA template processing (15 min) and real-time amplification (36 min), can be accomplished within 1 h. The SARS-COV-2 rRT-MCDA test established in the current report is a novel, ultrafast, ultrasensitive, and highly specific detection method, which can be performed as a valuable screening and/or diagnostic tool for COVID-19 in clinical application.

Effectiveness and durability of BNT162b2 vaccine against hospital and emergency department admissions due to SARS-CoV-2 omicron sub-lineages BA.1 and BA.2 in a large health system in the USA: a test-negative, case-control study

BACKGROUND

The SARS-CoV-2 omicron (B.1.1.529 BA.1) lineage was first detected in November, 2021, and is associated with reduced vaccine effectiveness. By March, 2022, BA.1 had been replaced by sub-lineage BA.2 in the USA. As new variants evolve, vaccine performance must be continually assessed. We aimed to evaluate the effectiveness and durability of BNT162b2 (Pfizer-BioNTech) against hospital and emergency department admissions for BA.1 and BA.2.

METHODS

In this test-negative, case-control study, we sourced data from the electronic health records of adult (aged ≥18 years) members of Kaiser Permanente Southern California (KPSC), which is a health-care system in the USA, who were admitted to one of 15 KPSC hospitals or emergency departments (without subsequent hospitalisation) between Dec 27, 2021, and June 4, 2022, with an acute respiratory infection and were tested for SARS-CoV-2 by RT-PCR. Omicron sub-lineage was determined by use of sequencing, spike gene target failure, and the predominance of variants in certain time periods. Our main outcome was the effectiveness of two or three doses of BNT162b2 in preventing emergency department or hospital admission. Variant-specific vaccine effectiveness was evaluated by comparing the odds ratios from logistic regression models of vaccination between test-positive cases and test-negative controls, adjusting for the month of admission, age, sex, race and ethnicity, body-mass index, Charlson Comorbidity Index, previous influenza or pneumococcal vaccines, and previous SARS-CoV-2 infection. We also assessed effectiveness by the time since vaccination. This study is registered at ClinicalTrials.gov, NCT04848584, and is ongoing.

FINDINGS

Of 65 813 total admissions during the study period, we included 16 994 in our analyses, of which 7435 were due to BA.1, 1056 were due to BA.2, and 8503 were not due to SARS-CoV-2. In adjusted analyses, two-dose vaccine effectiveness was 40% (95% CI 27 to 50) for hospitalisation and 29% (18 to 38) for emergency department admission against BA.1 and 56% (31 to 72) for hospitalisation and 16% (-5 to 33) for emergency department admission against BA.2. Three-dose vaccine effectiveness was 79% (74 to 83) for hospitalisation and 72% (67 to 77) for emergency department admission against BA.1 and 71% (55 to 81) for hospitalisation and 21% (1 to 37) for emergency department admission against BA.2. Less than 3 months after the third dose, vaccine effectiveness was 80% (74 to 84) for hospitalisation and 74% (69 to 78) for emergency department admission against BA.1. Vaccine effectiveness 3 months or more after the third dose was 76% (69 to 82) against BA.1-related hospitalisation and 65% (56 to 73) against BA.1-related emergency department admission. Against BA.2, vaccine effectiveness was 74% (47 to 87) for hospitalisation and 59% (40 to 72) for emergency department admission at less than 3 months after the third dose and 70% (53 to 81) for hospitalisation and 5% (-21 to 25) for emergency department admission at 3 months or more after the third dose.

INTERPRETATION

Two doses of BNT162b2 provided only partial protection against BA.1-related and BA.2-related hospital and emergency department admission, which underscores the need for booster doses against omicron. Although three doses offered high levels of protection (≥70%) against hospitalisation, variant-adapted vaccines are probably needed to improve protection against less severe endpoints, like emergency department admission, especially for BA.2.

FUNDING

Pfizer.

Potential of green tea EGCG in neutralizing SARS-CoV-2 Omicron variant with greater tropism toward the upper respiratory tract

Background

COVID-19 due to SARS-CoV-2 infection has had an enormous adverse impact on global public health. As the COVID-19 pandemic evolves, the WHO declared several variants of concern (VOCs), including Alpha, Beta, Gamma, Delta, and Omicron. Compared with earlier variants, Omicron, now a dominant lineage, exhibits characteristics of enhanced transmissibility, tropism shift toward the upper respiratory tract, and attenuated disease severity. The robust transmission of Omicron despite attenuated disease severity still poses a great challenge for pandemic control. Under this circumstance, its tropism shift may be utilized for discovering effective preventive approaches.

Scope and approach

This review aims to estimate the potential of green tea epigallocatechin gallate (EGCG), the most potent antiviral catechin, in neutralizing SARS-CoV-2 Omicron variant, based on current knowledge concerning EGCG distribution in tissues and Omicron tropism.

Key findings and conclusions

EGCG has a low bioavailability. Plasma EGCG levels are in the range of submicromolar concentrations following green tea drinking, or reach at most low μM concentrations after pharmacological intervention. Nonetheless, its levels in the upper respiratory tract could reach concentrations as high as tens or even hundreds of μM following green tea consumption or pharmacological intervention. An approach for delivering sufficiently high concentrations of EGCG in the pharynx has been developed. Convincing data have demonstrated that EGCG at tens to hundreds of μM can dramatically neutralize SARS-CoV-2 and effectively eliminate SARS-CoV-2-induced cytopathic effects and plaque formation. Thus, EGCG, which exhibits hyperaccumulation in the upper respiratory tract, deserves closer investigation as an antiviral in the current global battle against COVID-19, given Omicron's greater tropism toward the upper respiratory tract.

Characteristics of the Severe Acute Respiratory Syndrome Coronavirus 2 Omicron BA.2 Subvariant in Jilin, China from March to May 2022

Background and Objectives

In the midst of the pandemic, new coronavirus mutants continue to emerge; the most relevant variant worldwide is omicron. Here, patients who recovered from the disease living in Jilin Province were analyzed to identify factors affecting the severity of omicron infection and to provide insights into its spread and early indication.

Methods

In this study, 311 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were divided into two groups. Data on the patients' demographic characteristics and laboratory tests, including platelet count (PLT), neutrophil count (NE), C-reactive protein (CRP), serum creatinine (SCR), and neutrophil-to-lymphocyte ratio (NLR), were collected. The biomarkers for moderate and severe coronavirus disease 2019 (COVID-19) and factors affecting the incubation period and time to subsequent negative nucleic acid amplification test (NAAT) were also investigated.

Results

Age, gender, vaccination, hypertension, stroke, chronic obstructive pulmonary disease (COPD)/chronic bronchitis/asthma, and some laboratory tests were statistically different between the two groups. In the receiver operating characteristic (ROC) analysis, PLT and CRP had higher area under the ROC curve values. In the multivariate analysis, age, hypertension, COPD/chronic bronchitis/asthma, and CRP were correlated with moderate and severe COVID-19. Moreover, age was correlated with longer incubation. In the Kaplan-Meier curve analysis, gender (male), CRP, and NLR were associated with longer time to subsequent negative NAAT.

Conclusions

Older patients with hypertension and lung diseases were likely to have moderate or severe COVID-19, and younger patients might have a shorter incubation. A male patient with high CRP and NLR levels might take more time to turn back negative in the NAAT.

Characterization of SARS-CoV-2 recombinants and emerging Omicron sublineages

The SARS-CoV-2 Omicron is currently the predominant circulating variant in the COVID-19 pandemic. The dominating Omicron sublineages respond to host immune pressure and develop advantageous mutations or genetic recombination, which result in variants that are more contagious or better at escaping immune responses in response to previous infection or vaccination. Meanwhile, multiple genetic recombination events have been reported in coinfection cases, the majority of which have resulted from the recombination between co-circulating Omicron BA.1 (or BA.1.1) and Delta variant or BA.2. Here, we review the knowledge and characterization of recombination for SARS-CoV-2 at the population level, provide an update on the occurrence of newly circulating Omicron sublineages, and discuss the effectiveness of novel vaccines/therapeutic drugs against the Omicron variant.

Genomic Epidemiology of the SARS-CoV-2 Epidemic in Cyprus from November 2020 to October 2021: The Passage of Waves of Alpha and Delta Variants of Concern

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 resulted in the coronavirus disease 2019 (COVID-19) pandemic, which has had devastating repercussions for public health. Over the course of this pandemic, the virus has continuously been evolving, resulting in new, more infectious variants that have frequently led to surges of new SARS-CoV-2 infections. In the present study, we performed detailed genetic, phylogenetic, phylodynamic and phylogeographic analyses to examine the SARS-CoV-2 epidemic in Cyprus using 2352 SARS-CoV-2 sequences from infected individuals in Cyprus during November 2020 to October 2021. During this period, a total of 61 different lineages and sublineages were identified, with most falling into three groups: B.1.258 & sublineages, Alpha (B.1.1.7 & Q. sublineages), and Delta (B.1.617.2 & AY. sublineages), each encompassing a set of S gene mutations that primarily confer increased transmissibility as well as immune evasion. Specifically, these lineages were coupled with surges of new infections in Cyprus, resulting in the following: the second wave of SARS-CoV-2 infections in Cyprus, comprising B.1.258 & sublineages, during late autumn 2020/beginning of winter 2021; the third wave, comprising Alpha (B.1.1.7 & Q. sublineages), during spring 2021; and the fourth wave, comprising Delta (B.1.617.2 & AY. sublineages) during summer 2021. Additionally, it was identified that these lineages were primarily imported from and exported to the UK, Greece, and Sweden; many other migration links were also identified, including Switzerland, Denmark, Russia, and Germany. Taken together, the results of this study indicate that the SARS-CoV-2 epidemic in Cyprus was characterized by successive introduction of new lineages from a plethora of countries, resulting in the generation of waves of infection. Overall, this study highlights the importance of investigating the spatiotemporal evolution of the SARS-CoV-2 epidemic in the context of Cyprus, as well as the impact of protective measures placed to mitigate transmission of the virus, providing necessary information to safeguard public health.

Emergence of SARS-CoV-2 Omicron variant and strategies for tackling the infection

INTRODUCTION

Nowadays, emerging SARS-CoV-2 Omicron, the novel highly mutated VOC, has quickly spread as the dominant variant in over 190 countries worldwide through the first part of 2022, which is influencing the infectivity, transmissibility, pathogenicity, and severity of COVID-19 pandemic. Additionally, clinical cases and experimental studies have reported that Omicron variant likely leads to weakened immune protection elicited by infection, antibody therapies, and vaccines. The new wave, from late February, 2022, was escalated abruptly by higher levels of transmission of Omicron BA.2 sublineage in China.

METHODS AND RESULTS

Following a systematic database search, this review summarizes the salient features of Omicron sublineages, and their impact on transmissibility, disease severity as well as the efficacy of the available vaccines and treatment against the Omicron.

CONCLUSION

We hope this study will provide a scientific reference for alleviating the burden of COVID-19.

Insight into SARS-CoV-2 Omicron variants in Saudi Arabian genomic isolates

OBJECTIVES

To investigate the emergent mutations involved in the evolutionary stages of the virus for better management of pandemic.

METHODS

This cross-sectional genomic investigation was performed on February 28, 2022, at the Biology Department, Faculty of Science, Tabuk University. Numerous mutations were searched in genomic isolates of Omicron variant prevalent in the Kingdom of Saudi Arabian. Whole-genome sequences were retrieved from genomic databases and were subjected to the Global Initiative on Sharing Avian Influenza Data (GISAID) CoVsurver for the Omicron variant detection and mutations.

RESULTS

Approximately 8.755 million SARS-CoV-2 genomes were reported to GISAID on February 28, 2022, of which 1270 have been reported from the Kingdom of Saudi Arabia. Among the 1270 genomes, 30 were Omicron variants. Among the Saudi Arabian genomes, 30 were detected as Omicron variants. Twenty-four unique mutations have been detected in membrane, envelope, spike and non-structural proteins (NSP) 12, NSP3, and NSP2. Ten of these unique mutations have been detected in spike protein.

CONCLUSION

The current study provides useful information for further experimental investigation of mutation's effects on virus transmission, severity, and vaccine efficacy.

Dual-targeting cyclic peptides of receptor-binding domain (RBD) and main protease (Mpro) as potential drug leads for the treatment of SARS-CoV-2 infection

The receptor-binding domain (RBD) and the main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) play a crucial role in the entry and replication of viral particles, and co-targeting both of them could be an attractive approach for the treatment of SARS-CoV-2 infection by setting up a "double lock" in the viral lifecycle. However, few dual RBD/Mpro-targeting agents have been reported. Here, four novel RBD/Mpro dual-targeting peptides, termed as MRs 1-4, were discovered by an integrated virtual screening scheme combining molecular docking-based screening and molecular dynamics simulation. All of them possessed nanomolar binding affinities to both RBD and Mpro ranging from 14.4 to 39.2 nM and 22.5-40.4 nM, respectively. Further pseudovirus infection assay revealed that the four selected peptides showed >50% inhibition against SARS-CoV-2 pseudovirus at a concentration of 5 µM without significant cytotoxicity to host cells. This study leads to the identification of a class of dual RBD/Mpro-targeting agents, which may be developed as potential and effective SARS-CoV-2 therapeutics.

Emergence of New SARS-CoV2 Omicron Variants after the Change of Surveillance and Control Strategy

In January 2022, there was a global and rapid surge of the Omicron variant of SARS-CoV-2 related to more transmission. This coincided with an increase in the incidence in Asturias, a region where rapid diagnosis and containment measures had limited the circulation of variants.

METHODS

From January to June 2022, 34,591 variants were determined by the SNP method. From them, 445 were characterized by the WGS method and classified following pangolin program and phylogenic analysis.

RESULTS

The Omicron variant went from being detected in 2438 (78%) samples in the first week of January 2021 to 4074 (98%) in the third week, according to the SNP method. Using the WGS method, 159 BA.1 (35.7%), 256 BA.2 (57.6%), 1 BA.4 (0.2%) and 10 BA.5 (2.2%) Omicron variants were found. Phylogenetic analysis detected that three new sub-clades, BA.2,3.5, BA.2.56 and BF1, were circulating.

CONCLUSIONS

The increase in the incidence of SARS-CoV2 caused the circulation of new emerging variants. Viral evolution calls for continuous genomic surveillance.

The role transition of radiotherapy for the treatment of liver cancer in the COVID-19 era

The uncontrollable COVID-19 crises in the SARS-CoV-2 high-prevalence areas have greatly disrupted the routine treatment of liver cancer and triggered a role transformation of radiotherapy for liver cancer. The weight of radiotherapy in the treatment algorithm for liver cancer has been enlarged by the COVID-19 pandemic, which is helpful for the optimal risk-benefit profile.

Effectiveness and safety analysis of SanHanHuaShi granules for the treatment of coronavirus disease 2019: Study protocol and statistical analysis plan for a randomized, parallel-controlled, open-label clinical trial

Background: Coronavirus disease 2019 (COVID-19) was declared a global pandemic in March 2020 by the World Health Organization (WHO). As of July 2, 2022, COVID-19 has caused more than 545 million infections and 6.3 million deaths worldwide, posing a significant threat to human health. Currently, there is still a lack of effective prevention and control strategies for the variation and transmission of SARS-CoV-2. Traditional Chinese medicine (TCM), which has a unique theoretical system, has treated various conditions for thousands of years. Importantly, recent studies have revealed that TCM contributed significantly to COVID-19. SanHanHuaShi (SHHS) granules, a Chinese herbal medicine, which has been included in Protocol for the Diagnosis and Treatment of Novel Coronavirus Disease 2019 (6th to 9th editions) issued by the National Health Commission of China and used to prevent and treat COVID-19 disease. A previous retrospective cohort study showed that SHHS could significantly reduce the severity of mild and moderate COVID-19. However, there is an absence of high-quality randomized controlled clinical studies to confirm the clinical effectiveness of SHHS. Therefore, a clinical study protocol and a statistical analysis plan were designed to investigate the efficacy and safety of SHHS for the prevention and treatment of COVID-19. This study will increase the integrity and data transparency of the clinical research process, which is of great significance for improving the practical application of SHHS granules in the future.

Methods and analysis: The study was designed as a 7-day, randomized, parallel controlled, open-label, noninferiority clinical trial of positive drugs. A total of 240 patients with mild and moderate COVID-19 will be enrolled and randomly assigned to receive SanHanHuaShi granules or LianHuaQingWen granules treatment in a 1:1 ratio. Disease classification, vital signs, SARS-CoV-2 nucleic acid testing, symptoms, medications, adverse events, and safety evaluations will be recorded at each visit. The primary outcome will be the clinical symptom recovery rate. Secondary outcomes will include the recovery time of clinical symptoms, negative conversion time of SARS-CoV-2 nucleic acid test negative conversion rate, hospitalization time, antipyretic time, rate of conversion to severe patients, and time and rate of single symptom recovery. Adverse incidents and safety assessments will be documented. All data will be analyzed using a predetermined statistical analysis plan, including our method for imputation of missing data, primary and secondary outcome analyses, and safety outcomes.

Discussion: The results of this study will provide robust evidence to confirm the effectiveness and safety of SHHS in the treatment of COVID-19.

Clinical Trial Registration:http://www.chictr.org.cn. Trial number: ChiCTR2200058080. Registered on 29 March 2022.