ETIDIOH - NEW

  Highlights •  Middle East respiratory syndrome-coronavirus was first detected in 2012 in Saudi Arabia. •  Since 2012, Middle East respiratory syndrome caused 2626 confirmed cases. •  20% of cases involve contact with dromedary camels or their products. •  Human-to-human spread occurs, mainly in healthcare settings. •  A case fatality rate is 36-40%. Source: IJID Regions,  https://www.sciencedirect.com/science/article/pii/S2772707625001663?via%3Dihub ____

  ABSTRACT Cell cultures are widely used to study infectious respiratory diseases and to test therapeutics; however, they do not faithfully recapitulate the architecture and complexity of the human respiratory tract . Lung organoids have emerged as an alternative model that partially overcomes this key disadvantage. Lung organoids can be cultured in various formats that offer potential for studying highly pathogenic viruses . However, the effects of these different formats on virus infection remain unexplored, leaving their relative value unclear. In this study, we generated primary lung organoids from human donor cells and used them to derive monolayers and air-liquid interface (ALI) cultures with the goal of comparing the replication kinetics of two circulating highly pathogenic coronaviruses , severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ) and Middle East respiratory syndrome coronavirus ( MERS-CoV ). Infection studies revealed that organoid-derived monolayers di...

  Abstract COVID-19 and long COVID are characterized by a dysregulated immune response. However, the role of macrophages during viral infection is poorly defined. Here we demonstrate that SARS-CoV-2 infection results in increased macrophage numbers and extensive formation of enlarged lipid-laden macrophages or foam cells using humanized mice , rhesus macaques and post-mortem human lung tissue . Notably, infection by other coronaviruses tested, SARS-CoV-1, MERS-CoV and two bat coronaviruses (SHC014-CoV or WIV1-CoV), did not result in macrophage proliferation or foam cell formation. Foam cells in SARS-CoV-2-infected human lung tissue display a pro-fibrotic and pro-thrombotic phenotype as they are enriched for genes associated with platelet activation and aggregation , as well as extracellular matrix organization and collagen synthesis . After viral clearance, macrophage numbers remain elevated, and lung fibrosis and thrombi persist . Importantly, we show that pre-exposure prophylaxis...

  Abstract Outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) in humans are driven by recurring zoonotic spillover from camels , leading to demand for camel vaccination . With two vaccine candidates shown to reduce infectiousness, there is a need to better understand transmission of MERS-CoV in camels and assess the potential impact of vaccination . To help address this, we used age-stratified seroprevalence data and a combination of modelling methodologies to estimate key epidemiological quantities including MERS-CoV transmissibility in camels and to estimate vaccine impact on infection incidence. Transmissibility was higher in West Asia (R0 interquartile range 7-14) compared to Africa (3-5) and South Asia (2-3), highlighting the need for setting-specific vaccination strategies. Modelling suggested that even if the vaccine only reduced infectiousness rather than susceptibility to infection, vaccinating calves could achieve large reductions in incidence in moderat...

  Abstract SARS-CoV and MERS-CoV are two coronaviruses that have received significant attention due to their high pathogenicity and mortality rates in human populations . In this study, we compared their evolutionary dynamics to provide a One Health perspective on their differences in terms of the results of disease control. The phylogenetic network of SARS-CoVs showed that human isolates gathered into a “super-spreader” cluster and were distinct from civet isolates . In contrast, dromedary camel- and human-isolated MERS-CoVs were clustered together. Thus, most clades of MERS-CoV can infect humans , and MERS-CoVs seem to more easily spill over the animal-to-human interface. Additionally, the civet can be easily controlled , while the intermediate host (dromedary camels) of MERS-CoV is an important livestock species , so it is impossible to eliminate all animals. This further leads to difficulties in disease control in MERS. Although MERS-CoVs are endemic to dromedary camels in both...

Highlights •  Conserved T cell epitope regions elicit strong CD4+ and CD8+ T cell responses in SARS2-exposed •  CTERs enhance cross-reactivity across multiple Betacoronaviruses •  Targeting non-spike proteins expands immune breadth and HLA coverage •  Removing low population coverage regions preserves cross-reactivity Summary The COVID-19 pandemic highlighted the critical need for vaccine strategies capable of addressing emerging viral threats . Betacoronaviruses, including severe acute respiratory syndrome coronavirus ( SARS-CoV ), Middle East respiratory syndrome ( MERS ), and SARS-CoV-2 , present significant pandemic risks due to their zoonotic potential and genetic diversity . T cell-mediated immunity has demonstrated durable responses and strong cross-reactivity, offering a promising avenue for achieving broad immunity within a viral family. In this study, we combined comprehensive epitope mapping with sequence conservation analyses to identify conserved T cell ...

Abstract Background Dromedary camels are known carriers of Middle East respiratory syndrome coronavirus (MERS-CoV). This study aimed to identify respiratory RNA viruses circulating in the nasal cavities of camels that could potentially cause disease in humans. Methods Shotgun metagenomic paired-end sequencing was performed on four pools of nasal swabs collected from 40 camels originating from Sudan and Djibouti, using the MiSeq platform. Results Alphacoronavirus 229E was commonly detected in the camel pools. MERS-CoV was found in both pools from Sudan and one from Djibouti . Camel parainfluenza virus 3 (PIV3) was detected in the male camel pool from Sudan . Furthermore, near-complete (99.9 %) metagenomic assembled genomes (MAGs) of alphacoronavirus 229E (SIAU MAG01) and MERS-CoV (SIAU MAG02) were retrieved from the female camel pool from Sudan . Another MAG of alphacoronavirus 229E (SIAU MAG03) was recovered from a male camel pool imported from Sudan . In the phylogenetic analysis, SIA...

Abstract Identifying receptors for bat coronaviruses is critical for spillover risk assessment, countermeasure development, and pandemic preparedness . While Middle East respiratory syndrome coronavirus ( MERS-CoV ) uses DPP4 for entry , the receptors of many MERS-related betacoronaviruses remain unknown . The bat merbecovirus HKU5 was previously shown to have an entry restriction in human cells . Using both pseudotyped and full-length virus, we show that HKU5 uses Pipistrellus abramus bat ACE2 but not human ACE2 or DPP4 as a receptor. Cryo-electron microscopy analysis of the virus-receptor complex and structure-guided mutagenesis reveal a spike and ACE2 interaction that is distinct from other ACE2-using coronaviruses. MERS-CoV vaccine sera poorly neutralize HKU5 informing pan-merbecovirus vaccine design. Notably, HKU5 can also engage American mink and stoat ACE2 , revealing mustelids as potential intermediate hosts. These findings highlight the versatility of merbecovirus receptor use...

ABSTRACT The threat to global health security posed by Middle East respiratory syndrome coronavirus (MERS-CoV) and emerging MERS-like coronaviruses highlights the need to develop safe and efficient vaccines. Viral vector vaccines have been shown to be effective and are widely used to prevent various viral diseases because they mimic natural infection and induce a more comprehensive immune response. Herein, we developed a novel bat influenza A virus-based vaccine vector by replacing the open reading frame of either bat influenza hemagglutinin or neuraminidase with that of the hemagglutinin-esterase-fusion gene from influenza D virus , which can infect multiple species, including humans and camels . We then generated a temperature-sensitive, cold-adapted, and attenuated MERS vaccine candidate expressing the clade A MERS-CoV spike S1, referred to as Len_S1, using the developed bat influenza vector and demonstrated its safety and immunogenicity. A single-dose intranasal immunization with L...

Abstract Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus that causes acute respiratory disease after transmission via close contact with camels . In contrast to the incidence of MERS-CoV human infections in the Middle East , MERS-CoV infections in the Horn of Africa have been rarely reported despite the high number of camels and common camel–human interactions in the area. Whether passive cross-sectional sampling misses active human cases is a significant gap in our understanding of MERS-CoV epidemiology and its impact in the Horn of Africa. To address this gap, we conducted a prospective cross-sectional study at Laisamis Catholic Hospital in northern Kenya’s camel pastoralist community . A total of 942 patients with acute respiratory symptoms were enrolled over 18 months (August 2022–February 2024); 54% of these individuals reported frequent contact with camels and consumption of camel products. Testing via reverse transcriptase – polymerase chain reaction ...

Abstract Introduction Middle East respiratory syndrome (MERS) is a zoonotic viral respiratory disease caused by the Middle East respiratory syndrome coronavirus (MERS-CoV), associated with severe clinical outcomes and high mortality. Objectives Our study examined the kinetics of anti-MERS-CoV IgM and IgG antibodies during the acute and convalescent phases of infection, focusing on their correlations with clinical variables such as age and viral load. Methods Serum samples were collected from PCR-confirmed MERS-CoV patients (n = 23) during both phases and compared to healthy controls (n = 23) using validated ELISA-based assays. Results IgM levels peaked in the acute phase and declined significantly in the convalescent phase , while IgG levels were sustained and markedly higher during recovery . Correlation analyses revealed positive relationships between antibody levels and patient age (acute IgM: r = 0.56, p < 0.01; convalescent IgG: r = 0.59, p < 0.01) and viral loads (acute IgM...

{Excerpt} The World Health Organization (WHO) had recently announced on May 12 , 2025, the reporting of nine new laboratory-confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in Saudi Arabia [1]. This announcement is a sobering reminder that while the global community remains focused on emergent threats like avian influenza or post-pandemic resilience, endemic zoonotic diseases like MERS-CoV may continue to circulate, evolve, and exploit gaps in infection prevention. (...) Source: Journal of Epidemiology and Global Health,  https://link.springer.com/article/10.1007/s44197-025-00426-6 ____

  Summary -- What is already known about this topic? - Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) is a zoonotic virus transmitted sporadically from camels to humans , with limited subsequent human-to-human transmission . Most reported human cases of MERS have occurred in or near the Arabian Peninsula . Standardized clinical and epidemiologic criteria are used to determine who in the United States should be tested for MERS-CoV. In the United States , the last identified and confirmed MERS cases occurred in 2014 . -- What is added by this report? - Global reported MERS cases have declined substantially since the COVID-19 pandemic. Numbers of travelers entering the United States from in or near the Arabian Peninsula declined during the COVID-19 pandemic, but now have returned to prepandemic levels. U.S. MERS-CoV testing declined during 2017–2023 and remains low relative to prepandemic years. Clinical and epidemiologic criteria to guide U.S. testing were updated in ...

Situation at a glance Between 1 March and 21 April 2025, the Ministry of Health (MoH) of the Kingdom of Saudi Arabia (KSA) reported nine cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection . Two of these cases died . Among the nine cases, a cluster of seven cases were identified in Riyadh , including six health and care workers who acquired the infection from caring for a single infected patient . The cluster was identified through contact tracing and subsequent testing of all contacts, with four of the six health and care workers being asymptomatic and two showing only mild , nonspecific signs. The notification of these cases does not change the overall risk assessment , which remains moderate at both the global and regional levels. These cases show that the virus continues to pose a threat in countries where it is circulating in dromedary camels and spilling over into the human population . WHO recommends implementation of targeted infection prevention and cont...

Abstract Despite accumulating evidence that bat-derived coronaviruses often require intermediate hosts to facilitate transmission to humans1, the potential role of fur animals in zoonotic coronavirus spillovers has largely been overlooked2. Here we report the isolation and characterization of a novel mink respiratory coronavirus (MRCoV) from farmed minks with pneumonia . Notably, MRCoV uses angiotensin-converting enzyme 2 (ACE2) as a receptor and can infect mink, bat, monkey, and human cells . Cryo-electron microscopy analysis revealed that the MRCoV receptor-binding domain (RBD) binds to the same interface on ACE2 receptors as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RBD , despite exhibiting notable structural differences. We identify the key determinants on ACE2 and MRCoV RBD that confer efficient binding. HKU5-33S, a bat coronavirus closely related to MRCoV , utilizes ACE2 of bat Pipistrellus abramus and requires only two amino acid substitutions to adapt to mink...

Abstract Three studies recently published in Cell reveal distinct ACE2 binding interactions across the merbecoviruses , uncovering how HKU5 can use ACE2s of many non-human hosts and identifying a novel HKU5 lineage capable of using human ACE2. These findings highlight merbecovirus receptor plasticity and caution for preparedness against potential merbecovirus threats. Source: Cell, Host & Microbe,  https://www.cell.com/cell-host-microbe/abstract/S1931-3128(25)00096-4?rss=yes ____

Highlights The current review highlights the following major findings from the literature. 1.The genomic control of pathogenic properties of murine β-coronavirus. 2.Plausible mechanism of virus-induced neuroinflammatory demyelination and axonal loss. 3.Spike protein as a major determinant of MHV-induced neuropathogenesis. 4.The minimal essential motif in fusion peptide responsible for neuropathogenesis. 5.mCoV research sheds light on hCoV neuropathogenesis and helps design anti-virals. Abstract Coronaviruses have emerged as a significant challenge to human health . While earlier outbreaks of coronaviruses such as SARS-CoV and MERS-CoV posed serious threats , the recent SARS-CoV-2 pandemic has heightened interest in coronavirus research due to its pulmonary pathology , in addition to its neurological manifestations . In addition, the patients who have recovered from SARS-CoV-2 infection show long-term symptoms such as anosmia, brain fog and long COVID. A major hurdle in studying these v...

Situation at a glance This is the bi-annual update on the Middle East respiratory syndrome coronavirus (MERS-CoV) infections reported to the World Health Organization (WHO) from the Kingdom of Saudi Arabia (KSA).  From 6 September 2024 to 28 February 2025, four laboratory-confirmed cases of MERS-CoV infection , including two deaths, were reported to WHO by the Ministry of Health of the KSA.  One of the four cases was a secondary case exposed to the virus in a healthcare facility (nosocomial transmission).  Close contacts of the four cases were followed up by the Ministry of Health.  No additional secondary cases have been detected.  The notification of these four cases does not alter the overall risk assessment, which remains moderate at both the global and regional levels.  The reporting of these cases shows that the virus continues to pose a threat in countries where it is circulating in dromedary camels, particularly those in the Middle East. Description...

Significance Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic coronavirus that continues to cause periodic outbreaks in humans with a case-fatality rate of approximately 35%. MERS-CoV generally transmits poorly, but superspreading events are well documented. Efficient human-to-human transmission of respiratory viruses generally correlates with a tropism for the upper respiratory tract, but this tropism for MERS-CoV remains poorly understood. Characterizing the MERS-CoV tropism in the human upper respiratory tract is of critical importance to understand its epidemiology and pandemic potential of future MERS-CoV variants and other dipeptidyl peptidase 4 (DPP4)-utilizing coronaviruses present in animal reservoirs. Abstract Transmissibility of respiratory viruses is a complex viral trait that is intricately linked to tropism. Several highly transmissible viruses, including severe acute respiratory syndrome coronavirus 2 and Influenza viruses, specifically targ...

Highlights •   A distinct HKU5 coronavirus lineage (HKU5-CoV-2) is discovered in bats •  Bat HKU5-CoV-2 uses human ACE2 receptor and ACE2 orthologs from multiple species •   Bat HKU5-CoV-2 RBD engages human ACE2 with a distinct binding mode from other CoVs •  Bat HKU5-CoV-2 was isolated and infect human-ACE2-expressing cells Summary Merbecoviruses comprise four viral species with remarkable genetic diversity: MERS -related coronavirus, Tylonycterisbat coronavirus HKU4, Pipistrellusbat coronavirus HKU5, and Hedgehog coronavirus 1. However, the potential human spillover risk of animal merbecoviruses remains to be investigated. Here, we reported the discovery of HKU5-CoV lineage 2 (HKU5-CoV-2) in bats that efficiently utilize human angiotensin-converting enzyme 2 (ACE2) as a functional receptor and exhibits a broad host tropism . Cryo-EM analysis of HKU5-CoV-2 receptor-binding domain (RBD) and human ACE2 complex revealed an entirely distinct binding mode compared with o...