Middle East respiratory syndrome vaccines

MICaFVi: A Novel Magnetic Immuno-Capture Flow Virometry Nano-Based Diagnostic Tool for Detection of Coronaviruses

COVID-19 has resulted in a pandemic that aggravated the world's healthcare systems, economies, and education, and caused millions of global deaths. Until now, there has been no specific, reliable, and effective treatment to combat the virus and its variants. The current standard tedious PCR-based tests have limitations in terms of sensitivity, specificity, turnaround time, and false negative results. Thus, an alternative, rapid, accurate, and sensitive diagnostic tool that can detect viral particles, without the need for amplification or viral replication, is central to infectious disease surveillance. Here, we report MICaFVi (Magnetic Immuno-Capture Flow Virometry), a novel precise nano-biosensor diagnostic assay for coronavirus detection which combines the MNP-based immuno-capture of viruses for enrichment followed by flow-virometry analysis, enabling the sensitive detection of viral particles and pseudoviruses. As proof of concept, virus-mimicking spike-protein-coated silica particles (VM-SPs) were captured using anti-spike-antibody-conjugated MNPs (AS-MNPs) followed by detection using flow cytometry. Our results showed that MICaFVi can successfully detect viral MERS-CoV/SARS-CoV-2-mimicking particles as well as MERS-CoV pseudoviral particles (MERSpp) with high specificity and sensitivity, where a limit of detection (LOD) of 3.9 µg/mL (20 pmol/mL) was achieved. The proposed method has great potential for designing practical, specific, and point-of-care testing for rapid and sensitive diagnoses of coronavirus and other infectious diseases.

Significant perspectives on various viral infections targeted antiviral drugs and vaccines including COVID-19 pandemicity

A virus enters a living organism and recruits host metabolism to reproduce its own genome and proteins. The viral infections are intricate and cannot be completely removed through existing antiviral drugs. For example, the herpes, influenza, hepatitis and human immunodeficiency viruses are a few dreadful ones amongst them. Significant studies are needed to understand the viral entry and their growth in host cells to design effective antivirals. This review emphasizes the range of therapeutical antiviral drugs, inhibitors along with vaccines to fight against viral pathogens, especially for combating COVID-19. Moreover, we have provided the basic and in depth information about viral targets, drugs availability, their mechanisms of action, method of prevention of viral diseases and highlighted the significances of anticoagulants, convalescent plasma for COVID-19 treatment, scientific details of airborne transmission, characteristics of antiviral drug delivery using nanoparticles/carriers, nanoemulsions, nanogels, metal based nanoparticles, alike the future nanosystems through nanobubbles, nanofibers, nanodiamonds, nanotraps, nanorobots and eventually, the therapeutic applications of micro- and nanoparticulates, current status for clinical development against COVID-19 together with environmental implications of antivirals, gene therapy etc., which may be useful for repurposing and designing of novel antiviral drugs against various dreadful diseases, especially the SARS-CoV-2 and other associated variants.

Fusion Expression and Immune Effect of PCV2 Cap Protein Tandem Multiantigen Epitopes with CD154/GM-CSF

Porcine circovirus associated diseases (PCVAD) is a contagious disease of swine caused by porcine circovirus type 2 (PCV2). The capsid protein (Cap) is the sole structural protein and the main antigen of PCV2. Cap is the principal immunogenic protein and induces humoral and cellular immunity. CD154 and GM-CSF are immune adjuvants that enhance responses to vaccines. However, whether these two cellular molecules could produce an enhanced effect in PCV2 vaccines still needs to be further studied. The results of PCR and restriction enzyme showed that the recombinant lentiviral plasmids pCDH-TB-Cap, pCDH-TB-Cap-CD154 and pCDH-TB-Cap were successfully constructed. Western blot and IFA showed that the three fusion proteins TB-Cap, TB-Cap-CD154 and TB-Cap-GM-CSF were stably expressed in CHO-K1 cells. Indirect ELISA assay showed that mice immunized with TB-Cap-CD154 and TB-Cap-GM-CSF fusion proteins produced higher PCV2-specific antibodies than mice immunized with the TB-Cap and a commercial vaccine (p < 0.0001). Moreover, lymphocyte proliferation and flow cytometry showed that the cellular immune response of each immune group was significantly enhanced (p < 0.0001). After PCV2 challenge, the results revealed that the viral loads in serum, lung and kidney of all vaccinated groups were significantly lower than the PBS group (p < 0.0001). The transcription levels of IL-2, IFN-gamma, IL-4 and IL-10 cytokines in the TB-Cap, TB-Cap-CD154 and TB-Cap-GM-CSF groups were significantly higher than those in the PBS and recombinant vaccine groups (p < 0.0001). These results indicated that CD154 and GM-CSF could enhance the ability of TB-Cap protein to induce the body to produce PCV2 specific antibodies and increase the transcription level of cytokines. Thus, CD154 and GM-CSF molecules were a powerful immunoadjuvant for PCV2 subunit vaccines. The novel TB-Cap-CD154 and TB-Cap-GM-CSF subunit vaccine has the potential to be used for the prevention and control of PCVAD.

Potential Effects of Coronaviruses on the Liver: An Update

The coronaviruses that cause notable diseases, namely, severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and coronavirus disease 2019 (COVID-19), exhibit remarkable similarities in genomic components and pathogenetic mechanisms. Although coronaviruses have widely been studied as respiratory tract pathogens, their effects on the hepatobiliary system have seldom been reported. Overall, the manifestations of liver injury caused by coronaviruses typically involve decreased albumin and elevated aminotransferase and bilirubin levels. Several pathophysiological hypotheses have been proposed, including direct damage, immune-mediated injury, ischemia and hypoxia, thrombosis and drug hepatotoxicity. The interaction between pre-existing liver disease and coronavirus infection has been illustrated, whereby coronaviruses influence the occurrence, severity, prognosis and treatment of liver diseases. Drugs and vaccines used for treating and preventing coronavirus infection also have hepatotoxicity. Currently, the establishment of optimized therapy for coronavirus infection and liver disease comorbidity is of significance, warranting further safety tests, animal trials and clinical trials.

Direct Observation of Repeated Infections With Endemic Coronaviruses

BACKGROUND

Although the mechanisms of adaptive immunity to pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are still unknown, the immune response to the widespread endemic coronaviruses HKU1, 229E, NL63, and OC43 provide a useful reference for understanding repeat infection risk.

METHODS

Here we used data from proactive sampling carried out in New York City from fall 2016 to spring 2018. We combined weekly nasal swab collection with self-reports of respiratory symptoms from 191 participants to investigate the profile of recurring infections with endemic coronaviruses.

RESULTS

During the study, 12 individuals tested positive multiple times for the same coronavirus. We found no significant difference between the probability of testing positive at least once and the probability of a recurrence for the betacoronaviruses HKU1 and OC43 at 34 weeks after enrollment/first infection. We also found no significant association between repeat infections and symptom severity, but found strong association between symptom severity and belonging to the same family.

CONCLUSIONS

This study provides evidence that reinfections with the same endemic coronavirus are not atypical in a time window shorter than 1 year and that the genetic basis of innate immune response may be a greater determinant of infection severity than immune memory acquired after a previous infection.

The immune response and immune evasion characteristics in SARS-CoV, MERS-CoV, and SARS-CoV-2: Vaccine design strategies

The worldwide outbreak of SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 as a novel human coronavirus, was the worrying news at the beginning of 2020. Since its emergence complicated more than 870,000 individuals and led to more than 43,000 deaths worldwide. Considering to the potential threat of a pandemic and transmission severity of it, there is an urgent need to evaluate and realize this new virus's structure and behavior and the immunopathology of this disease to find potential therapeutic protocols and to design and develop effective vaccines. This disease is able to agitate the response of the immune system in the infected patients, so ARDS, as a common consequence of immunopathological events for infections with Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV, and SARS-CoV-2, could be the main reason for death. Here, we summarized the immune response and immune evasion characteristics in SARS-CoV, MERS-CoV, and SARS-CoV-2 and therapeutic and prophylactic strategies with a focus on vaccine development and its challenges.

Product of natural evolution (SARS, MERS, and SARS-CoV-2); deadly diseases, from SARS to SARS-CoV-2

SARS-CoV-2, the virus causing COVID-19, is a single-stranded RNA virus belonging to the order Nidovirales, family Coronaviridae, and subfamily Coronavirinae. SARS-CoV-2 entry to cellsis initiated by the binding of the viral spike protein (S) to its cellular receptor. The roles of S protein in receptor binding and membrane fusion makes it a prominent target for vaccine development. SARS-CoV-2 genome sequence analysis has shown that this virus belongs to the beta-coronavirus genus, which includes Bat SARS-like coronavirus, SARS-CoV and MERS-CoV. A vaccine should induce a balanced immune response to elicit protective immunity. In this review, we compare and contrast these three important CoV diseases and how they inform on vaccine development.

Antiviral activity against Middle East Respiratory Syndrome coronavirus by Montelukast, an anti-asthma drug

Middle East Respiratory Syndrome (MERS) is a respiratory disease caused by a coronavirus (MERS-CoV). Since its emergence in 2012, nosocomial amplifications have led to its high epidemic potential and mortality rate of 34.5%. To date, there is an unmet need for vaccines and specific therapeutics for this disease. Available treatments are either supportive medications in use for other diseases or those lacking specificity requiring higher doses. The viral infection mode is initiated by the attachment of the viral spike glycoprotein to the human Dipeptidyl Peptidase IV (DPP4). Our attempts to screen antivirals against MERS led us to identify montelukast sodium hydrate (MSH), an FDA-approved anti-asthma drug, as an agent attenuating MERS-CoV infection. We showed that MSH directly binds to MERS-CoV-Receptor-Binding Domain (RBD) and inhibits its molecular interaction with DPP4 in a dose-dependent manner. Our cell-based inhibition assays using MERS pseudovirions demonstrated that viral infection was significantly inhibited by MSH and was further validated using infectious MERS-CoV culture. Thus, we propose MSH as a potential candidate for therapeutic developments against MERS-CoV infections.

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Montelukast (MSH) directly binds to MERS-CoV-Receptor-Binding Domain (RBD).

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MSH inhibits MERS-Spike pseudovirion (PV) entry.

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MSH attenuates live MERS-CoV infection in host cells.

How to Survive COVID-19 Even If the Vaccine Fails

Coronavirus disease 2019 (COVID-19) has created an emergency of epic proportions. While a vaccine may be forthcoming, this is not guaranteed, as discussed herein. The potential problems and ominous signs include (1) lung injury that developed in animals given an experimental vaccine for the severe acute respiratory syndrome coronavirus (SARS-CoV)-1; (2) a perversion of adaptive immune responses called antibody-dependent enhancement of infection that occurs in SARS-CoV-1 and that may occur in people vaccinated for COVID-19; (3) the frequent and recurrent infections that are caused by respiratory coronaviruses; and (4) the appearance of mutations in SARS-CoV-2 proteins, which raise the specter of vaccine escape mutants. Because success is uncertain, alternatives to vaccines need to be vigorously pursued during this critical moment in the pandemic. Alternatives include (1) engineered monoclonal antibodies that do not cause antibody-dependent enhancement; (2) cocktails of antiviral drugs and inhibitors of the cellular proteins required for SARS-CoV-2 replication; (3) interferons; and (4) anticoagulants, antioxidants, and immune modulators. To organize and coordinate the systematic investigation of existing therapies and new therapies (as they emerge), a Covid-19 clinical trials network is needed to provide (1) robust funding (on a par with vaccine funding) and administration; (2) an adaptive trial design committee to prioritize interventions and review results in real time; (3) a computer interface to facilitate patient enrollment, make data available to investigators, and present findings; (4) a practice guidelines study group; and (5) a mobile corps of COVID-19 experts available for rapid deployment, to assist local health care providers and enroll patients in trials as outbreaks occur. To combat the COVID-19 pandemic and future mass contagions, the network would be a cornerstone of a comprehensive infectious diseases research program.

Passive immunization: Paradoxical and traditional method for new pandemic challenge COVID-19

World has been suffering from pandemic caused by mysterious Coronavirus. The novel member of Coronaviridae causing COVID-19 disease is named as SARS-Cov-2. Its first case was reported in China by the end of 2019, but its exponential spread has wrapped entire globe, suspended and is penalizing mankind. A retrospective meta-analysis study showed that outbreaks of Middle East Respiratory Syndrome (MERS) and SARS-Cov-1 (Coronaviridae), influenza infection H1N1 and West-African Ebola caused lower mortality than this new pandemic COVID-19. Virus has appeared as a new human pathogen so to counter COVID-19 no specific vaccine, monoclonal antibodies have been manufactured till day. The outbreak of novel Coronavirus is treated with antimicrobial drugs but they have their own mild side effects. But the drastic spread of COVID-19 compels us also to use other ways to counter pandemic. Thus, passive immunization can be opted to hold back this mysterious virus. Passive immunization has been in use since early 20th century and showed its effectiveness against all previous infectious outbreaks including MERS and SARS-Cov-1 members of Coronaviridae. The review argues that convalescent plasma is an explicit option for containment of COVID-19 disease.

The Current and Future State of Vaccines, Antivirals and Gene Therapies Against Emerging Coronaviruses

Emerging coronaviruses (CoV) are constant global public health threats to society. Multiple ongoing clinical trials for vaccines and antivirals against CoVs showcase the availability of medical interventions to both prevent and treat the future emergence of highly pathogenic CoVs in human. However, given the diverse nature of CoVs and our close interactions with wild, domestic and companion animals, the next epidemic zoonotic CoV could resist the existing vaccines and antivirals developed, which are primarily focused on Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS CoV). In late 2019, the novel CoV (SARS-CoV-2) emerged in Wuhan, China, causing global public health concern. In this review, we will summarize the key advancements of current vaccines and antivirals against SARS-CoV and MERS-CoV as well as discuss the challenge and opportunity in the current SARS-CoV-2 crisis. At the end, we advocate the development of a "plug-and-play" platform technologies that could allow quick manufacturing and administration of broad-spectrum countermeasures in an outbreak setting. We will discuss the potential of AAV-based gene therapy technology for in vivo therapeutic antibody delivery to combat SARS-CoV-2 outbreak and the future emergence of severe CoVs.

Single intranasal immunization with chimpanzee adenovirus-based vaccine induces sustained and protective immunity against MERS-CoV infection

The recently identified Middle East Respiratory Syndrome Coronavirus (MERS-CoV) causes severe and fatal acute respiratory illness in humans. However, no approved prophylactic and therapeutic interventions are currently available. The MERS-CoV envelope spike protein serves as a crucial target for neutralizing antibodies and vaccine development, as it plays a critical role in mediating viral entry through interactions with the cellular receptor, dipeptidyl peptidase 4 (DPP4). Here, we constructed a recombinant rare serotype of the chimpanzee adenovirus 68 (AdC68) that expresses full-length MERS-CoV S protein (AdC68-S). Single intranasal immunization with AdC68-S induced robust and sustained neutralizing antibody and T cell responses in BALB/c mice. In a human DPP4 knock-in (hDPP4-KI) mouse model, it completely protected against lethal challenge with a mouse-adapted MERS-CoV (MERS-CoV-MA). Passive transfer of immune sera to naïve hDPP4-KI mice also provided survival advantages from lethal MERS-CoV-MA challenge. Analysis of sera absorption and isolated monoclonal antibodies from immunized mice demonstrated that the potent and broad neutralizing activity was largely attributed to antibodies targeting the receptor binding domain (RBD) of the S protein. These results show that AdC68-S can induce protective immune responses in mice and represent a promising candidate for further development against MERS-CoV infection in both dromedaries and humans.

Recent Advances in the Vaccine Development Against Middle East Respiratory Syndrome-Coronavirus

Middle East respiratory syndrome (MERS) is a deadly viral respiratory disease caused by MERS-coronavirus (MERS-CoV) infection. To date, there is no specific treatment proven effective against this viral disease. In addition, no vaccine has been licensed to prevent MERS-CoV infection thus far. Therefore, our current review focuses on the most recent studies in search of an effective MERS vaccine. Overall, vaccine candidates against MERS-CoV are mainly based upon the viral spike (S) protein, due to its vital role in the viral infectivity, although several studies focused on other viral proteins such as the nucleocapsid (N) protein, envelope (E) protein, and non-structural protein 16 (NSP16) have also been reported. In general, the potential vaccine candidates can be classified into six types: viral vector-based vaccine, DNA vaccine, subunit vaccine, nanoparticle-based vaccine, inactivated-whole virus vaccine and live-attenuated vaccine, which are discussed in detail. Besides, the immune responses and potential antibody dependent enhancement of MERS-CoV infection are extensively reviewed. In addition, animal models used to study MERS-CoV and evaluate the vaccine candidates are discussed intensively.

An updated roadmap for MERS-CoV research and product development: focus on diagnostics

Diagnostics play a central role in the early detection and control of outbreaks and can enable a more nuanced understanding of the disease kinetics and risk factors for the Middle East respiratory syndrome-coronavirus (MERS-CoV), one of the high-priority pathogens identified by the WHO. In this review we identified sources for molecular and serological diagnostic tests used in MERS-CoV detection, case management and outbreak investigations, as well as surveillance for humans and animals (camels), and summarised the performance of currently available tests, diagnostic needs, and associated challenges for diagnostic test development and implementation. A more detailed understanding of the kinetics of infection of MERS-CoV is needed in order to optimise the use of existing assays. Notably, MERS-CoV point-of-care tests are needed in order to optimise supportive care and to minimise transmission risk. However, for new test development, sourcing clinical material continues to be a major challenge to achieving assay validation. Harmonisation and standardisation of laboratory methods are essential for surveillance and for a rapid and effective international response to emerging diseases. Routine external quality assessment, along with well-characterised and up-to-date proficiency panels, would provide insight into MERS-CoV diagnostic performance worldwide. A defined set of Target Product Profiles for diagnostic technologies will be developed by WHO to address these gaps in MERS-CoV outbreak management.

Immunogenicity of Different Forms of Middle East Respiratory Syndrome S Glycoprotein

The Middle East respiratory syndrome coronavirus (MERS-CoV) was identified in 2012 during the first Middle East respiratory syndrome (MERS) outbreaks. MERS-CoV causes an acute lower-respiratory infection in humans, with a fatality rate of ~35.5%. Currently, there are no registered vaccines or means of therapeutic protection against MERS in the world. The MERS-CoV S glycoprotein plays the most important role in the viral life cycle (virus internalization). The S protein is an immunodominant antigen and the main target for neutralizing antibodies. In the present study, the immunogenicities of five different forms of the MERS-CoV S glycoprotein were compared: the full-length S glycoprotein, the full-length S glycoprotein with the transmembrane domain of the G glycoprotein of VSV (S-G), the receptor-binding domain (RBD) of the S glycoprotein, the membrane-fused RBD (the RBD fused with the transmembrane domain of the VSV G glycoprotein (RBD-G)), and the RBD fused with Fc of human IgG1 (RBD-Fc). Recombinant vectors based on human adenoviruses type 5 (rAd5) were used as delivery vehicles. Vaccination with all of the developed rAd5 vectors elicited a balanced Th1/Th2 response in mice. The most robust humoral immune response was induced after the animal had been vaccinated with the membrane-fused RBD (rAd5-RBD-G). Only immunization with membrane forms of the glycoprotein (rAd5-S, rAd5-S-G, and rAd5-RBD-G) elicited neutralizing antibodies among all vaccinated animals. The most significant cellular immune response was induced after vaccination of the animals with the full-length S (rAd5-S). These investigations suggest that the full-length S and the membrane form of the RBD (RBD-G) are the most promising vaccine candidates among all the studied forms of S glycoprotein.

A Zika virus vaccine expressing premembrane-envelope-NS1 polyprotein

Current efforts to develop Zika virus (ZIKV) subunit vaccines have been focused on pre-membrane (prM) and envelope (E) proteins, but the role of NS1 in ZIKV-specific immune response and protection is poorly understood. Here, we develop an attenuated recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing ZIKV prM-E-NS1 as a polyprotein. This vectored vaccine candidate is attenuated in mice, where a single immunization induces ZIKV-specific antibody and T cell immune responses that provide protection against ZIKV challenge. Co-expression of prM, E, and NS1 induces significantly higher levels of Th2 and Th17 cytokine responses than prM-E. In addition, NS1 alone is capable of conferring partial protection against ZIKV infection in mice even though it does not induce neutralizing antibodies. These results demonstrate that attenuated rVSV co-expressing prM, E, and NS1 is a promising vaccine candidate for protection against ZIKV infection and highlights an important role for NS1 in ZIKV-specific cellular immune responses.

MERS-CoV: Understanding the Latest Human Coronavirus Threat

Human coronaviruses cause both upper and lower respiratory tract infections in humans. In 2012, a sixth human coronavirus (hCoV) was isolated from a patient presenting with severe respiratory illness. The 60-year-old man died as a result of renal and respiratory failure after admission to a hospital in Jeddah, Saudi Arabia. The aetiological agent was eventually identified as a coronavirus and designated Middle East respiratory syndrome coronavirus (MERS-CoV). MERS-CoV has now been reported in more than 27 countries across the Middle East, Europe, North Africa and Asia. As of July 2017, 2040 MERS-CoV laboratory confirmed cases, resulting in 712 deaths, were reported globally, with a majority of these cases from the Arabian Peninsula. This review summarises the current understanding of MERS-CoV, with special reference to the (i) genome structure; (ii) clinical features; (iii) diagnosis of infection; and (iv) treatment and vaccine development.

Transgene expression in the genome of Middle East respiratory syndrome coronavirus based on a novel reverse genetics system utilizing Red-mediated recombination cloning

Middle East respiratory syndrome coronavirus (MERS-CoV) is a high-priority pathogen in pandemic preparedness research. Reverse genetics systems are a valuable tool to study viral replication and pathogenesis, design attenuated vaccines and create defined viral assay systems for applications such as antiviral screening. Here we present a novel reverse genetics system for MERS-CoV that involves maintenance of the full-length viral genome as a cDNA copy inserted in a bacterial artificial chromosome amenable to manipulation by homologue recombination, based on the bacteriophage λ Red recombination system. Based on a full-length infectious MERS-CoV cDNA clone, optimal genomic insertion sites and expression strategies for GFP were identified and used to generate a reporter MERS-CoV expressing GFP in addition to the complete set of viral proteins. GFP was genetically fused to the N-terminal part of protein 4a, from which it is released during translation via porcine teschovirus 2A peptide activity. The resulting reporter virus achieved titres nearly identical to the wild-type virus 48 h after infection of Vero cells at m.o.i. 0.001 (1×10⁵ p.f.u. ml^-1 and 3×10⁵ p.f.u. ml^-1, respectively), and allowed determination of the 50 % inhibitory concentration for the known MERS-CoV inhibitor cyclosporine A based on fluorescence readout. The resulting value was 2.41 µM, which corresponds to values based on wild-type virus. The reverse genetics system described herein can be efficiently mutated by Red-mediated recombination. The GFP-expressing reporter virus contains the full set of MERS-CoV proteins and achieves wild-type titres in cell culture.

Middle East respiratory syndrome coronavirus: five years later

INTRODUCTION

In the past five years, there have been 1,936 laboratory-confirmed cases of Middle East Respiratory Syndrome coronavirus (MERS-CoV) in 27 countries, with a mortality rate of 35.6%. Most cases have arisen in the Middle East, particularly the Kingdom of Saudi Arabia, however there was a large hospital-associated outbreak in the Republic of Korea in 2015. Exposure to dromedary camels has been recognized by the World Health Organization (WHO) as a risk factor in primary cases, but the exact mechanisms of transmission are not clear. Rigorous application of nationally defined infection prevention and control measures has reduced the levels of healthcare facility-associated outbreaks. There is currently no approved specific therapy or vaccine available. Areas covered: This review presents an overview of MERS-CoV within the last five years, with a particular emphasis on the key areas of transmission, infection control and prevention, and therapies and vaccines. Expert commentary: MERS-CoV remains a significant threat to public health as transmission mechanisms are still not completely understood. There is the potential for mutations that could increase viral transmission and/or virulence, and zoonotic host range. The high mortality rate highlights the need to expedite well-designed randomized clinical trials for direct, effective therapies and vaccines.

Middle East Respiratory Syndrome: Emergence of a Pathogenic Human Coronavirus

In 2012, a zoonotic coronavirus was identified as the causative agent of Middle East respiratory syndrome and was named MERS coronavirus (MERS-CoV). As of August 11, 2016, the virus has infected 1,791 patients, with a mortality rate of 35.6%. Although MERS-CoV generally causes subclinical or mild disease, infection can result in serious outcomes, including acute respiratory distress syndrome and multi-organ failure in patients with comorbidities. The virus is endemic in camels in the Arabian Peninsula and Africa and thus poses a consistent threat of frequent reintroduction into human populations. Disease prevalence will increase substantially if the virus mutates to increase human-to-human transmissibility. No therapeutics or vaccines are approved for MERS; thus, development of novel therapies is needed. Further, since many MERS cases are acquired in healthcare settings, public health measures and scrupulous attention to infection control are required to prevent additional MERS outbreaks.

What is the experience from previous mass gathering events? Lessons for Zika virus and the Olympics 2016

All previous experiences from different mass gathering show that vaccine preventable diseases is the most important infections like influemza, hepatitis A, polio and meningitis. Three mass gathering held in Africa during the Ebola outbreak accepted participants from West Africa and was able to handle the theoretical risk without any incident. Therefore we believe that the Olympc games in Rio de Janeiro should not be canceled. The number of visitors to the games is a tine fraction (1%) of other visitors to Zika endemic con tries and it will have no measurable effect on the risk of spreading Zika virus, if the games was cancelled.