Anti-MERS-CoV Spike Protein (aa 1-1297) monoclonal antibody, clone 834

Middle East Respiratory Syndrome-related coronavirus (MERS-CoV) is a novel coronavirus first identified in Saudi Arabia in 2012. As a zoonotic virus, MERS-CoV is primarily transmitted to humans through contact with infected dromedary camels. Since its discovery, MERS-CoV has been found in camels in several countries across the Middle East, Africa, and South Asia. Research suggests that MERS-CoV likely originated in bats and was transmitted to camels at some point in history. Although most cases of the virus occur in the Middle East, there have been reports of imported cases in other countries globally. By the end of November 2019, there were 2,494 laboratory-confirmed cases worldwide, with 858 deaths, resulting in a mortality rate of approximately 34.4%. Saudi Arabia has reported the largest number of cases, comprising the vast majority of the global total. MERS-CoV belongs to the Betacoronavirus genus, the same group as the severe acute respiratory syndrome (SARS) coronavirus, which caused an outbreak in 2003. MERS-CoV is a positive-sense single-stranded RNA virus with a genome encoding several structural proteins, including the spike protein (S), envelope protein (E), membrane protein (M), and nucleocapsid protein (N). The spike protein plays a crucial role in MERS-CoV's interaction with host cells by binding to receptors on the host cell surface. MERS-CoV uses a receptor called dipeptidyl peptidase 4 (DPP4) to bind to target cells, which is different from the angiotensin-converting enzyme 2 (ACE2) receptor used by the SARS coronavirus. The uniqueness of the DPP4 receptor provides novel targets for diagnosing and treating MERS. The MERS-CoV genome is approximately 30kb in size and is classified as a C lineage β-coronavirus. Its genome structure resembles that of other coronaviruses, with the first two-thirds encoding replication enzymes and the last third encoding structural and accessory proteins. The MERS-CoV genome can be divided into two major clades, clade A and clade B, with clade B containing the majority of strains. Although the mutation rate of MERS-CoV is relatively low, its infectiousness and pathogenicity remain significant public health concerns. Studies have shown that the genome sequence similarity of MERS-CoV exceeds 99%, indicating minimal genetic variation. This genetic stability provides a relatively consistent target for vaccine and antiviral drug development.

Figure 1. Schematic organization of the human coronavirus (α and β CoV) genome (Source: Chafekar A, Fielding BC, 2018)

The clinical presentation of MERS-CoV infection varies widely, ranging from asymptomatic to rapidly progressive acute respiratory distress syndrome (ARDS) and even death. Initial symptoms are typically nonspecific, such as fever, cough, headache, myalgia, and difficulty breathing. Severe cases often involve acute pneumonia, septic shock, and multi-organ failure, with up to 50% of patients requiring intensive care. Particularly vulnerable groups, such as those with underlying conditions like diabetes, obesity, and hypertension, are at a significantly higher risk of severe disease and death. Clinical data show that 75% of confirmed MERS cases had at least one chronic illness, with an even higher prevalence among those who died. MERS-CoV primarily spreads through close contact with infected individuals, especially in healthcare settings, where transmission has been observed from contaminated surfaces. The virus can survive on surfaces for several days, making infection control measures in healthcare facilities crucial. During infection, high levels of the virus can be detected in respiratory secretions, particularly tracheal secretions and bronchoalveolar lavage fluid, which often have higher viral loads than nasal swabs. The virus can also be excreted through feces, serum, and urine, and respiratory secretions may remain infectious for up to 25 days after recovery. Due to the lack of specific antiviral drugs and vaccines, the current treatment for MERS primarily relies on supportive care. These supportive measures include maintaining vital signs and managing complications, such as using ventilators, fluid therapy, and broad-spectrum antibiotics to prevent secondary infections. While some antiviral drugs, like ribavirin and interferon combination therapy, have shown some efficacy in non-human primate models, their effectiveness in clinical settings remains unproven. Therefore, treating severe MERS cases presents significant challenges.

In terms of vaccine development, although progress has been made, MERS vaccines remain in the early stages of research. Scientists are currently focusing on vaccines targeting the spike protein's receptor-binding domain (RBD), which is the main target for neutralizing antibodies and can effectively block the virus from binding to host cells. However, one of the challenges of developing coronavirus vaccines is the short duration of immunity they confer, and elderly individuals tend to have a weaker immune response. Additionally, vaccines may exacerbate immune responses in some patients, leading to more severe lung damage. These challenges present significant technical and safety hurdles in MERS vaccine development. Despite the relatively limited global spread of MERS, the virus still poses a potential threat to global public health. The high mortality rate and close association with healthcare settings mean that every outbreak has the potential to place a heavy burden on public health systems. Monitoring the spread of MERS, understanding the virus's pathogenic mechanisms, and developing effective vaccines and treatments remain priorities for scientists and public health experts worldwide. In summary, while MERS cases are relatively few compared to other diseases, its high fatality rate and complex transmission mechanisms continue to present a serious global public health challenge. As research progresses, the development of vaccines and specific antiviral therapies against MERS provides hope for combating this threat. Nevertheless, further studies on MERS's virology, pathogenic mechanisms, and preventive strategies are essential for preparing for future coronavirus outbreaks.

Anti-MERS-CoV spike antibody
Anti-MERS coronavirus spike protein antibody
Anti-MERS-CoV S protein monoclonal antibody
Middle East respiratory syndrome coronavirus spike protein antibody