Non-Hodgkin's lymphoma complicated with human coronavirus HKU1 pneumonia: A case report and literature review.

Objective: To analyze the clinical manifestations, diagnostic methods and treatment process of the patients with non-Hodgkin's lymphoma complicated with human coronavirus(HCoV)-HKU1 pneumonia and improve the clinical medical staff's awareness of the disease, and to reduce the occurrence of clinical adverse events. Method(s): The clinical data of a patient with non-Hodgkin's lymphoma complicated with HCoV-HKU1 pneumonia with hot flashes and night sweats, dry cough and dry throat as the main clinical features who were hospitalized in the hospital in January 2021 were analyzed, and the relevant literatures were reviewed and the clinical manifestations and diagnosis of HCoV-HKU1 were analyzed. Result(s): The female patient was admitted to the hospital due to diagnosed non-Hodgkin's lymphoma for more than 2 months. The physical examination results showed Karnofsky score was 90 points;there was no palpable enlargement of systemic superfical lymph nodes;mild tenderness in the right lower abdomen, no rebound tenderness, and slightly thicker breath sounds in both lungs were found, and a few moist rales were heard in both lower lungs. The chest CT results showed diffuse exudative foci in both lungs, and the number of white blood cells in the urine analysis was 158 muL-1;next generation sequencing technique(NGS) was used the detect the bronchoalveolar lavage fluid, and HCoV-HKU1 pneumonia was diagnosed. At admission, the patient had symptoms such as dull pain in the right lower abdomen, nighttime cough, and night sweats;antiviral treatment with oseltamivir was ineffective. After treatment with Compound Sulfamethoxazole Tablets and Lianhua Qingwen Granules, the respiratory symptoms of the patient disappeared. The re-examination chest CT results showed the exudation was absorbed. Conclusion(s): The clinical symptoms of the patients with non-Hodgkin's lymphoma complicated with HCoV-HKU1 pneumonia are non-specific. When the diffuse shadow changes in the lungs are found in clinic, and the new coronavirus nucleic acid test is negative, attention should still be paid to the possibility of other HCoV infections. The NGS can efficiently screen the infectious pathogens, which is beneficial to guide the diagnosis and treatment of pulmonary infectious diseases more accurately.Copyright © 2023 Jilin University Press. All rights reserved.

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.

Historical perspective: other human coronavirus infectious diseases, SARS and MERS

Alphacoronaviruses (HCoV-229E and HCoV-NL63) and betacoronaviruses (HCoV-OC43 and HCoV-HKU1) are common causes of upper respiratory tract infection in humans. SARS-CoV-1 and MERS-CoV emerged in 2002 and 2012, respectively, with the potential of causing severe and lethal disease in humans, termed SARS and MERS, respectively. Bats appear to be the common natural source of SARS-like coronaviruses including SARS-CoV-1, but their role in MERS-CoV is less clear. Civet cats and dromedary camels are the intermediary animal sources for SARS-CoV-1 and MERS-CoV, respectively. Nosocomial outbreaks are hallmarks of SARS and MERS. MERS patients with comorbidities or immunosuppression tend to progress more rapidly to respiratory failure and have a higher case fatality rate than SARS patients. SARS has disappeared since 2004, while there are still sporadic cases of MERS in the Middle East. Continued global surveillance is essential for SARS-like coronaviruses and MERS-CoV to monitor changing epidemiology due to viral variants.Copyright © ERS 2021.

Human coronaviruses in the 'One Health' context

Seven human coronaviruses have been identified so far: four seasonal coronaviruses (HCoV-229E, HCoV-OC43, HCoV-NL63, HCoV-HKU1) and three novel coronaviruses (SARS-CoV, MERS-CoV, SARS-CoV-2). While seasonal coronaviruses cause only mild symptoms, novel coronaviruses cause severe and potentially fatal infections. All known coronaviruses originated in animals. Bats are considered as an origin for the majority of coronaviruses capable of infecting humans;however, rodents are proposed as natural hosts for HCoV-OC43 and HCoV-HKU1. Different animal species could serve as intermediate hosts including alpacas (HCoV-229E), livestock (HCoV-OC43), civet cats (SARS-CoV), camels (MERS-CoV), and pangolins (SARS-CoV-2). In Croatia, SARS-CoV-2 was detected in humans, pet animals, wildlife, and the environment. The COVID-19 pandemic has highlighted the role of the 'One Health' approach in the surveillance of zoonotic diseases.Copyright © 2022, University Hospital of Infectious Diseases. All rights reserved.

Epidemiology of Non-SARS-CoV2 Human Coronaviruses (HCoVs) in People Presenting with Influenza-like Illness (ILI) or Severe Acute Respiratory Infections (SARI) in Senegal from 2012 to 2020.

In addition to emerging coronaviruses (SARS-CoV, MERS, SARS-CoV-2), there are seasonal human coronaviruses (HCoVs): HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1. With a wide distribution around the world, HCoVs are usually associated with mild respiratory disease. In the elderly, young children and immunocompromised patients, more severe or even fatal respiratory infections may be observed. In Africa, data on seasonal HCoV are scarce. This retrospective study investigated the epidemiology and genetic diversity of seasonal HCoVs during nine consecutive years of influenza-like illness surveillance in Senegal. Nasopharyngeal swabs were collected from ILI outpatients or from SARI hospitalized patients. HCoVs were diagnosed by qRT-PCR and the positive samples were selected for molecular characterization. Among 9337 samples tested for HCoV, 406 (4.3%) were positive: 235 (57.9%) OC43, 102 (25.1%) NL63, 58 (14.3%) 229E and 17 (4.2%) HKU1. The four types circulated during the study period and a peak was noted between November and January. Children under five were the most affected. Co-infections were observed between HCoV types (1.2%) or with other viruses (76.1%). Genetically, HCoVs types showed diversity. The results highlighted that the impact of HCoVs must be taken into account in public health; monitoring them is therefore particularly necessary both in the most sensitive populations and in animals.

Impact of Azithromycin and 8-Hydroxychloroquine in 2019 Novel Coronavirus (COVID-19) Pandemic: A Systematic Review

As we know novel coronavirus is an emergent nuisance in this stipulated period. Corona virus is a group of enveloped viruses, with non-segmented, single stranded & positive sense RNA genomes. Human Corona virus is mainly subdivided into four categories such as 229E, NL63, OC43, HKU1. Epidemiologically it has a greater prevalence in the modern era. The features encountered in the clinical course of the disease are multifarious spanning from cough, sneezing, fever, breathlessness. It may take 2-14 days for a person to notice symptoms after infection. Azithromycin and 8 Hydroxychloroquine both plays an instrumental role for management of COVID-19. Azithromycin is a macrolide antibiotic and it binds with a 50s ribosome then inhibits bacterial protein synthesis. On the other hand 8-Hydroxychloroquine was approved by United State in the year of 1955 .Basically it is used as a antimalarial drugs . Briefly, in inflammatory conditions it binds with toll like receptor & blocks them. 8- hydroxychloroquine increases lysosomal pH in antigen presenting cells . In inflammatory conditions it blocks toll like receptors on plasmacytoid dendritic cells. In our review we focused on the role of Azithromycin, and 8-hydroxychloroquine in Covid-19 .Copyright © 2021 International Journal of Pharma and Bio Sciences. All rights reserved.

Coronaviruses

The coronaviruses belong to the family Coronaviridae in the order Nidovirales. CoVs are found globally and infect a variety of animals, causing illnesses that range from gastrointestinal tract infections, encephalitis and demyelination;and can be fatal. Humans coronaviruses (hCoVs) have traditionally been associated with self-limiting upper respiratory tract infections and gastrointestinal tract infections. In recent years, however, it has become increasingly evident that the hCoVs can cause more severe lower respiratory tract infections such as bronchitis, pneumonia and even acute respiratory distress syndrome (ARDS), and can lead to death. Seven CoVs are known to infect humans, with the four "common cold” CoVs circulating globally on a yearly basis. The remaining three are more pathogenic and have resulted in outbreaks with high mortality rates. This review focussed on the three pathogenic CoVs. © 2022 Elsevier Inc. All rights reserved.

Humoral response against SARS-CoV-2 and other endemic corona viruses

In a study of two Hospitals in Saxony (Chemnitz and Leipzig), we analyzed the antibody development towards SARS-CoV-2 and against a variety of endemic coronaviruses. Here we analyzed 760 sera from a Saxonian cohort for antibody reactivity against: Common cold coronaviruses, HCoV-229E, HCoV-HKU 1, HCoV-NL63 and HCoV-OC43, MERS-CoV and SARS-CoV. For the SARS CoV-2 immune response we tested the following antigens: Spike, S1, S2, RBD and nucleocapsid. These 11 antigen determinants were tested in a commercial multiplex Luminex based assay. We tested sera from 544 individuals (347 females and 197 males;498 SARS-CoV-2 PCR positive and 262 SARS-CoV-2 PCR negative) between May 2020 and March 2022. We observed up to 10% reactivity against the MERS virus in both the PCR positive and negative group. Against the common cold corona viruses 80%-90 % of the individuals in both groups show detectable antibodies. Regarding the antibody response against SARS-CoV a significant difference was observe. Only 19% of COVID-19 infected individuals show antibodies against the virus, while 81% of the PCR-positive individuals produced antibodies. The presence of antibodies against the SARS-CoV-2 is positively correlated with those against SARS-CoV (p = 0.001). No changes in endemic antibody responses were see in the two groups. The antibody status after first immunization event (infection/ vaccination) shows differences in nucleocapsiddirected antibody production, found in the natural infection group (about 60%). In the vaccination group, more individuals (up to 95%) show an immune response against Spike, S1 and RBD compare with natural infection. In summary, the examined cohort shows a general immunization up to 90% against most endemic corona viruses. Correlation analyses show cross-reactivity between SARS-CoV-2 and SARS-CoV. Longitudinal antibody analyses are under way, as also correlations of humoral response with immunogenetic factors.

Cellular Immune Responses to SARS-CoV-2 in Exposed Seronegative Individuals.

Some SARS-CoV-2-exposed individuals develop immunity without overt infection. We identified 11 individuals who were negative by nucleic acid testing during prolonged close contact and with no serological diagnosis of infection. As this could reflect natural immunity, cross-reactive immunity from previous coronavirus exposure, abortive infection due to de novo immune responses, or other factors, our objective was to characterize immunity against SARS-CoV-2 in these individuals. Blood was processed into plasma and peripheral blood mononuclear cells (PBMC) and screened for IgG, IgA, and IgM antibodies (Ab) against SARS-CoV-2 and common ß-coronaviruses OC43 and HKU1. Receptor blocking activity and interferon-alpha (IFN-α) in plasma were also measured. Circulating T cells against SARS-CoV-2 were enumerated and CD4+ and CD8+ T cell responses discriminated after in vitro stimulation. Exposed uninfected individuals were seronegative against SARS-CoV-2 spike (S) and selectively reactive against OC43 nucleocapsid protein (N), suggesting common ß-coronavirus exposure induced Ab cross-reactive against SARS-CoV-2 N. There was no evidence of protection from circulating angiotensin-converting enzyme (ACE2) or IFN-α. Six individuals had T cell responses against SARS-CoV-2, with four involving CD4+ and CD8+ T cells. We found no evidence of protection from SARS-CoV-2 through innate immunity or immunity induced by common ß-coronaviruses. Cellular immune responses against SARS-CoV-2 were associated with time since exposure, suggesting that rapid cellular responses may contain SARS-CoV-2 infection below the thresholds required for a humoral response.

The Circulation of Common Respiratory Viruses and Their Co-infection with Severe Acute Respiratory Syndrome Coronavirus 2 Before and After Coronavirus Disease of 2019 Vaccination

Background: Respiratory viruses play important roles in respiratory tract infections;they are the major cause of diseases such as the common cold, bronchiolitis, pneumonia, etc., in humans that circulate more often in the cold seasons. During the COVID-19 pandemic, many strict public health measures, such as hand hygiene, the use of face masks, social distancing, and quarantines, were implemented worldwide to control the pandemic. Besides controlling the COVID-19 pandemic, these introduced measures might change the spread of other common respiratory viruses. Moreover, with COVID-19 vaccination and reducing public health protocols, the circulation of other respiratory viruses probably increases in the community. Objective(s): This study aims to explore changes in the circulation pattern of common respiratory viruses during the COVID-19 pan-demic. Method(s): In the present study, we evaluated the circulation of seven common respiratory viruses (influenza viruses A and B, rhi-novirus, and seasonal human Coronaviruses (229E, NL63, OC43, and HKU1) and their co-infection with SARS-CoV-2 in suspected cases of COVID-19 in two time periods before and after COVID-19 vaccination. Clinical nasopharyngeal swabs of 400 suspected cases of COVID-19 were tested for SARS-CoV-2 and seven common respiratory viruses by reverse transcription real-time polymerase chain reaction. Result(s): Our results showed common respiratory viruses were detected only in 10% and 8% of SARS-CoV-2-positive samples before and after vaccination, respectively, in which there were not any significant differences between them (P-value = 0.14). Moreover, common viral respiratory infections were found only in 12% and 32% of SARS-CoV-2-negative specimens before and after vaccination, respectively, in which there was a significant difference between them (P-value = 0.041). Conclusion(s): Our data showed a low rate of co-infection of other respiratory viruses with SARS-CoV-2 at both durations, before and after COVID-19 vaccination. Moreover, the circulation of common respiratory viruses before the COVID-19 vaccination was lower, probably due to non-pharmaceutical interventions (NPI), while virus activity (especially influenza virus A) was significantly in-creased after COVID-19 vaccination with reducing strict public health measures.Copyright © 2023, Author(s).

SARS-CoV-2 in Terms of Medical Microbiology Laboratory.

Coronaviruses (CoV), which are in the Coronaviridae family, cause different severity of gastrointestinal, respiratory and systemic diseases in wild and domestic animals, and can lead to different clinical manifestations, ranging from colds to pneumonia, depending on immunity. To date, seven types of coronavirus have been identified as infectious agents in humans;of these, HCoV 229E, HCoV NL63, HCoV HKU1 and HCoV OC43 typically cause cold symptoms in immunocompetent individuals, while SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus) is zoonotic and cause severe respiratory diseases and deaths. SARS-CoV-2, the causative agent of COVID-19, is the seventh coronavirus identified as an infection agent in humans, which started in December 2019 in Wuhan, Hubei Province of China and was identified as a pandemic in a short time. Since the World Health Organization (WHO) defines SARS-CoV-2-sourced COVID-19 as a pandemic, and because of the increasing number of cases and deaths worldwide, structure of the novel virus and viral diagnosis methods gained importance respectively for vaccine studies and for controlling the outbreak caused by the virus.Copyright © 2020 Ankara Pediatric Hematology Oncology Training and Research Hospital. All rights reserved.

Screening for Potential Traditional Herbal Inhibitors Against 3-Chymo-trypsin-like Main Protease (3CLpro) from Four Different Coronaviruses: An in silico Approach

Background: The recent outbreak of the COVID-19 pandemic has raised a global health concern due to the unavailability of any vaccines or drugs. The repurposing of traditional herbs with broad-spectrum anti-viral activity can be explored to control or prevent a pandemic. Objective(s): The 3-chymotrypsin-like main protease (3CLpro), also referred to as the "Achilles' heel" of the coronaviruses (CoVs), is highly conserved among CoVs and is a potential drug target. 3CLpro is essential for the virus' life cycle. The objective of the study was to screen and identify broad--spectrum natural phytoconstituents against the conserved active site and substrate-binding site of 3CLpro of HCoVs. Method(s): Herein, we applied the computational strategy based on molecular docking to identify potential phytoconstituents for the non-covalent inhibition of the main protease 3CLpro from four different CoVs, namely, SARS-CoV-2, SARS-CoV, HCoV-HKU1, and HCoV-229E. Result(s): Our study shows that natural phytoconstituents in Triphala (a blend of Emblica officinalis fruit, Terminalia bellerica fruit, and Terminalia chebula fruit), namely chebulagic acid, chebulinic acid, and elagic acid, exhibited the highest binding affinity and lowest dissociation constants (Ki), against the conserved 3CLpro main protease of SARSCoV-2, SARS-CoV, HCoV-HKU1, and HCoV-229E. Besides, phytoconstituents of other herbs like Withania somnifera, Glycyrrhiza glabra, Hyssopus officinalis, Camellia sinensis, Prunella vulgaris, and Ocimum sanctum also showed good binding affinity and lower Ki against the active site of 3CLpro. The top-ranking phyto-constituents' binding interactions clearly showed strong and stable interactions with amino acid residues in the catalytic dyad (CYS-HIS) and substrate-binding pocket of the 3CLpro main proteases. Conclusion(s): This study provides a valuable scaffold for repurposing traditional herbs with anti--CoV activity to combat SARS-CoV-2 and other HCoVs until the discovery of new therapies.Copyright © 2021 Bentham Science Publishers.

The Genomes of SARS-CoV-2 and Related Coronaviruses: Are Accessory Proteins Key for Pathogenesis?

Objective: In January 2020, scientists deciphered the first genome of SARS-CoV-2 that has created a ravage in the world by infecting over 30 million people worldwide with above 0.95 million deaths as of mid-September 2020. With no potent therapeutics against COVID-19, research-ers around the world are relentlessly working for the development of a vaccine that can ease the pain the world is suffering today, both in terms of economic and psychological instability. Understanding the genome of SARS-CoV-2 is essential to decipher the keys that would help scientists to develop drugs or vaccines to prevent the disease. Method(s): Coronaviruses are not unknown to the human as other than SARS-CoV-2, at least six ad-ditional coronaviruses (SARS-CoV, MERS-CoV, HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1) are known that causes mild to severe diseases in human. We have compared the se-quences of these seven coronaviruses to identify the key regions which are responsible for pathoge-nesis. Result(s): The genomes of the seven coronaviruses that are known to infect humans differ signifi-cantly, especially in the regions of accessory genes. Conclusion(s): The analysis of these virus genomes is the key to find out targets for the development of a potent drug or vaccine against COVID-19.Copyright © 2021 Bentham Science Publishers.

Surveillance of endemic coronaviruses during the COVID-19 pandemic in Iran, 2021-2022.

Background: Human coronaviruses (HCoVs) 229E, OC43, HKU1, and NL63 are common viruses that continuously circulate in the human population. Previous studies showed the circulation of HCoVs during the cold months in Iran. We studied the circulation of HCoVs during coronavirus disease 2019 (COVID-19) pandemic to find the impact of pandemic on the circulation of these viruses. Methods: As a cross-sectional survey conducted during 2021 to 2022, of all throat swabs sent to Iran National Influenza Center from patients with severe acute respiratory infection, 590 samples were selected to test for HCoVs using one-step real-time RT-PCR. Results: Overall, 28 out of 590 (4.7%) tested samples were found to be positive for at least one HCoVs. HCoV-OC43 was the most common (14/590 or 2.4%), followed by HCoV-HKU1 (12/590 or 2%) and HCoV-229E (4/590 or 0.6%), while HCoV-NL63 was not detected. HCoVs were detected in patients of all ages and throughout the study period with peaks in the cold months of the year. Conclusions: Our multicenter survey provides insight into the low circulation of HCoVs during the COVID-19 pandemic in Iran in 2021/2022. Hygiene habits and social distancing measures might have important role in decreasing of HCoVs transmission. We believe that surveillance studies are needed to track the pattern of HCoVs distributions and detect changes in the epidemiology of such viruses to set out strategies in order to timely control the future outbreaks of HCoVs throughout the nation.

SARS-CoV-2 in Terms of Medical Microbiology Laboratory

Coronaviruses (CoV), which are in the Coronaviridae family, cause different severity of gastrointestinal, respiratory and systemic diseases in wild and domestic animals, and can lead to different clinical manifestations, ranging from colds to pneumonia, depending on immunity. To date, seven types of coronavirus have been identified as infectious agents in humans;of these, HCoV 229E, HCoV NL63, HCoV HKU1 and HCoV OC43 typically cause cold symptoms in immunocompetent individuals, while SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) and MERS-CoV (Middle East Respiratory Syndrome Coronavirus) is zoonotic and cause severe respiratory diseases and deaths. SARS-CoV-2, the causative agent of COVID-19, is the seventh coronavirus identified as an infection agent in humans, which started in December 2019 in Wuhan, Hubei Province of China and was identified as a pandemic in a short time. Since the World Health Organization (WHO) defines SARS-CoV-2-sourced COVID-19 as a pandemic, and because of the increasing number of cases and deaths worldwide, structure of the novel virus and viral diagnosis methods gained importance respectively for vaccine studies and for controlling the outbreak caused by the virus.

Analysis of Antibody Neutralisation Activity against SARS-CoV-2 Variants and Seasonal Human Coronaviruses NL63, HKU1, and 229E Induced by Three Different COVID-19 Vaccine Platforms.

Coronaviruses infections, culminating in the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic beginning in 2019, have highlighted the importance of effective vaccines to induce an antibody response with cross-neutralizing activity. COVID-19 vaccines have been rapidly developed to reduce the burden of SARS-CoV-2 infections and disease severity. Cross-protection from seasonal human coronaviruses (hCoVs) infections has been hypothesized but is still controversial. Here, we investigated the neutralizing activity against ancestral SARS-CoV-2 and the variants of concern (VOCs) in individuals vaccinated with two doses of either BNT162b2, mRNA-1273, or AZD1222, with or without a history of SARS-CoV-2 infection. Antibody neutralizing activity to SARS-CoV-2 and the VOCs was higher in BNT162b2-vaccinated subjects who were previously infected with SARS-CoV-2 and conferred broad-spectrum protection. The Omicron BA.1 variant was the most resistant among the VOCs. COVID-19 vaccination did not confer protection against hCoV-HKU1. Conversely, antibodies induced by mRNA-1273 vaccination displayed a boosting in their neutralizing activity against hCoV-NL63, whereas AZD1222 vaccination increased antibody neutralization against hCoV-229E, suggesting potential differences in antigenicity and immunogenicity of the different spike constructs used between various vaccination platforms. These data would suggest that there may be shared epitopes between the HCoVs and SARS-CoV-2 spike proteins.

Prevalence of Human Coronaviruses in Children and Phylogenetic Analysis of HCoV-OC43 during 2016-2022 in Riyadh, Saudi Arabia.

With the emergence of SARS-CoV-2, routine surveillance combined with sequence and phylogenetic analysis of coronaviruses is urgently required. In the current study, the four common human coronaviruses (HCoVs), OC43, NL63, HKU1, and 229E, were screened in 361 clinical samples collected from hospitalized children with respiratory symptoms during four winter seasons. RT-PCR-based detection and typing revealed different prevalence rates of HCoVs across the four seasons. Interestingly, none of the four HCoVs were detected in the samples (n = 100) collected during the winter season of the COVID-19 pandemic. HCoV-OC43 (4.15%) was the most frequently detected, followed by 229E (1.1%). Partial sequences of S and N genes of OC43 from the winter seasons of 2015/2016 and 2021/2022 were used for sequence and phylogenetic analysis. Multiple sequence alignment of the two Saudi OC43s strains with international strains revealed the presence of sequence deletions and several mutations, of which some changed their corresponding amino acids. Glycosylation profiles revealed a number of O-and N-glycosylation sites in both genes. Based on phylogenetic analysis, four genotypes were observed with Riyadh strains grouped into the genotype C. Further long-term surveillance with a large number of clinical samples and sequences is necessary to resolve the circulation patterns and evolutionary kinetics of OC43 in Saudi Arabia.

Roles of Sialyl Glycans in HCoV-OC43, HCoV-HKU1, MERS-CoV and SARS-CoV-2 Infections.

Ongoing seasonal HCoV-OC43 and HCoV-HKU1 (common cold), an ongoing zoonotic infection of highly lethal MERS-CoV in humans (MERS disease), and an ongoing pandemic SARS-CoV-2 (COVID-19) with high mutability giving some variants causing severe illness and death have been reported to attach to sialyl receptors via their spike (S) glycoproteins and via additional short spikes, hemagglutinin-esterase (HE) glycoproteins, for HCoV-OC43 and HCoV-HKU1. There is lack of zoonotic viruses that are origins of HCoV-HKU1 and the first recorded pandemic CoV (SARS-CoV-2) for studies. In this chapter, we review current knowledge of the roles of sialyl glycans in infections with these viruses in distinct infection stages. Determination of the similarities and differences in roles of sialyl glycans in infections with these viruses could lead to a better understanding of the pathogenesis and transmission that is essential for combating infections with CoVs that recognize sialyl glycans.

Variants of SARS coronavirus-2 and their potential impact on the future of the COVID-19 pandemic

The emergence of SARS-CoV-2 variants of concern (VOCs), especially the sweeping spread of the delta variant, and differing public health management strategies, have rendered global eradication of SARS-CoV-2 unlikely. The currently available COVID-19 vaccines, including the inactivated whole virus vaccines, mRNA vaccines, and adenovirus-vectored vaccines, are effective in protecting people from severe disease and death from COVID-19, but they may not confer good mucosal immunity to prevent the establishment of infection and subsequent viral shedding and transmission. Mucosal vaccines delivered via intranasal route may provide a promising direction, which, if given as a third dose after a two-dose series of intramuscular vaccination, likely promotes mucosal immunity in addition to boosting the systemic cell-mediated immunity and antibody response. However, immunity induced by vaccination, and natural infection as well, is likely to wane followed by re-infection as in the case of human coronaviruses OC43, 229E, NL63, and HKU1. It is a challenge to prevent and control COVID-19 worldwide with the increasing number of VOCs associated with increased transmissibility and changing antigenicity. Nevertheless, we may seek to end the current pandemic situation through mass vaccination and gradual relaxation of non-pharmaceutical measures, which would limit the incidence of severe COVID-19. Repeated doses of booster vaccine will likely be required, similar to influenza virus, especially for the elderly and the immunocompromised patients who are most vulnerable to infection.

Phylogenetic characteristics of Non-SARS human coronavirus in southern Taiwan, 2012-2013.

This study characterizes the phylogenetic relatedness of non-SARS human coronaviruses (HCoVs) in southern Taiwan by sequencing the nucleocapsid (N), spike (S), and RNA-dependent RNA polymerase (RdRp) genes directly from ten HCoV PCR-positive respiratory samples collected during 2012-2013. In the N, S1, and RdRp phylogeny, HCoV-OC43 in one and three samples was clustered with genotypes F and G, respectively, and HCoV-OC43 in sample YC101/TWN/2013 represented a recombination event between genotypes F and G. Amino acid substitutions in the S1 protein of HCoV-OC43 were also identified. In the N phylogeny, HCoV-HKU1 in one and two samples clustered with genotypes A and B, respectively, and HCoV-229E in two samples was clustered with genogroup 6. The genotypes and genogroup detected here were in line with the prevalent phylogenetic lineages reported outside of Taiwan during the contemporary period. In summary, three species of non-SARS HCoVs with different genotypes cocirculated in the community, with genetic evolution observed in HCoV-OC43.