An adenovirus-vectored vaccine based on the N protein of feline coronavirus elicit robust protective immune responses.

Feline coronavirus (FCoV) is an unsegmented, single-stranded RNA virus belonging to the Alphacoronavirus genus. It can cause fatal feline infectious peritonitis (FIP) in cats of any ages. Currently, there are no effective prevention and control measures to against FCoV. In this study, we developed a recombinant adenovirus vaccine, AD5-N, based on the nucleocapsid(N) protein of FCoV. The immunogenicity of AD5-N was evaluated through intramuscular immunization in 6-week-old Balb/c mice and 9-12 months old cats. Compared to the control group, AD5-N specifically induced a significant increase in IgG and SIgA levels in the vaccinated mice. Furthermore, AD5-N not only effectively promoted strong cellular immune responses in cats but also induced high levels of specific SIgA, effectively helping cats resist FCoV infection. Our findings suggest that adenovirus vector vaccines based on the N gene have the potential to become candidate vaccines for the prevention and control of FCoV infection.

Immunogenicity and protective efficacy of recombinant adenovirus expressing a novel genotype G2b PEDV spike protein in protecting newborn piglets against PEDV.

IMPORTANCE: Porcine epidemic diarrhea (PED) is a highly infectious and economically significant gastrointestinal disorder that affects pigs of all ages. Preventing and controlling PED is achieved by immunizing sows with vaccines, enabling passive piglet immunization via colostrum. The prevalence of G2b porcine epidemic diarrhea virus (PEDV) continues in China despite the use of commercial vaccines, raising questions regarding current vaccine efficacy and the need for novel vaccine development. Adenovirus serotype 5 (Ad5) has several advantages, including high transduction efficiency, a wide range of host cells, and the ability to infect cells at various stages. In this study, we expressed the immunogenic proteins of spike (S) using an Ad5 vector and generated a PED vaccine candidate by inducing significant humoral immunity. The rAd5-PEDV-S prevented PED-induced weight loss, diarrhea, and intestinal damage in piglets. This novel vaccine candidate strain possesses the potential for use in the pig breeding industry.

Hospitalização de idosos por COVID-19 no Paraná: uma análise de fatores associados / Hospitalización de personas mayores por COVID-19 en Paraná: un análisis de factores asociados / Hospitalization of elderly people due to COVID-19 in the State of Paraná, Brazil: analysis of associated factors

Resumo Objetivo Analisar a prevalência e os fatores associados à hospitalização de idosos com COVID-19 no estado do Paraná, PR, Brasil. Métodos Estudo transversal vinculado à coorte "Acompanhamento Longitudinal de adultos e idosos que receberam alta da internação hospitalar por COVID-19", realizado por meio de informações contidas nas fichas de notificação compulsória do Sistema de Informação de Agravos de Notificação. As análises foram realizadas através de frequências relativas e absolutas, com aplicação do teste de qui-quadrado adotado no modelo de regressão logística. A população do estudo englobou pessoas residentes no Estado do Paraná com idade de 60 anos ou mais, hospitalizadas por COVID-19 no período de março de 2020 a setembro de 2021. Resultados Foi identificada maior prevalência de hospitalização entre idosos com escolaridade igual ou maior a oito anos. Indivíduos não vacinados contra COVID-19 apresentaram maior chance de internação. O sexo masculino apresentou mais chance de admissão em Unidade de Terapia Intensiva em comparação com o sexo feminino. Doenças cardiovasculares, pneumopatia e obesidade aumentaram a prevalência da forma grave da doença. Conclusão Fatores tais como escolaridade e não adesão à vacinação contra COVID-19 podem aumentar o risco de hospitalização pela doença. Pessoas idosas do sexo masculino apresentam maior chance de hospitalização na UTI se comparadas às do sexo feminino; além disso, a não utilização de antivirais pode contribuir para o agravamento do estado de saúde.

Resumen Objetivo Analizar la prevalencia y los factores asociados a la hospitalización de personas mayores por COVID-19 en el estado de Paraná. Métodos Estudio transversal vinculado a la cohorte "Seguimiento longitudinal de adultos y personas mayores que recibieron alta de internación hospitalaria por COVID-19", realizado mediante información contenida en las fichas de notificación obligatoria del Sistema de Información de Agravios de Notificación. Los análisis fueron realizados a través de frecuencias relativas y absolutas, con aplicación de la prueba ji cuadrado adoptada en el modelo de regresión logística. La población del estudio incluyó personas residentes del estado de Paraná, de 60 años o más, hospitalizadas por COVID-19 en el período de marzo de 2020 a septiembre de 2021. Resultados Se identificó mayor prevalencia de hospitalización en personas mayores con escolaridad igual o mayor a ocho años. Individuos no vacunados contra COVID-19 presentaron mayor probabilidad de internación. El sexo masculino presentó más probabilidad de admisión en Unidad de Cuidados Intensivos en comparación con el sexo femenino. Enfermedades cardiovasculares, neumopatía y obesidad aumentaron la prevalencia de la forma grave de la enfermedad. Conclusión Factores tales como escolaridad y no adhesión a la vacunación contra COVID-19 pueden aumentar el riesgo de hospitalización por la enfermedad. Personas mayores de sexo masculino presentaron mayor probabilidad de hospitalización en la UCI al compararlas con las de sexo femenino. Además, la no utilización de antivirales puede contribuir al agravamiento del estado de salud.

Abstract Objective To analyze the prevalence and factors associated with hospitalization of elderly people with COVID-19 in the State of Paraná, PR, Brazil. Methods A cross-sectional study linked to the cohort "Longitudinal Monitoring of adults and elderly people who were discharged from hospital admission due to COVID-19", was carried out using information contained in the compulsory notification forms of the Notifiable Diseases Information System. Analyzes were carried out using relative and absolute frequencies, applying the chi-square test adopted in the logistic regression model. The study population included people aged 60 years or over and residing in the State of Paraná, who were hospitalized for COVID-19 from March 2020 to September 2021. Results A higher hospitalization prevalence was identified among elderly people with eight years of education or more. Individuals not vaccinated against COVID-19 had a greater chance of hospitalization. Males had a greater chance of admission to the Intensive Care Unit compared to females. Cardiovascular diseases, lung disease, and obesity have increased the prevalence of the severe form of the disease. Conclusion Factors such as education and non-adherence to vaccination against COVID-19 can increase the risk of hospitalization due to the disease. Elderly people of the male sex have a greater chance of hospitalization in the ICU compared to the female sex. Furthermore, not using antivirals can contribute to worsening health status.

Veratramine inhibits porcine epidemic diarrhea virus entry through macropinocytosis by suppressing PI3K/Akt pathway.

Porcine epidemic diarrhea (PED) is a contagious intestinal disease caused by α-coronavirus porcine epidemic diarrhea virus (PEDV). At present, no effective vaccine is available to prevent the disease. Therefore, research for novel antivirals is important. This study aimed to identify the antiviral mechanism of Veratramine (VAM), which actively inhibits PEDV replication with a 50 % inhibitory concentration (IC50) of ∼5 µM. Upon VAM treatment, both PEDV-nucleocapsid (N) protein level and virus titer decreased significantly. The time-of-addition assay results showed that VAM could inhibit PEDV replication by blocking viral entry. Importantly, VAM could inhibit PEDV-induced phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) activity and further suppress micropinocytosis, which is required for PEDV entry. In addition, PI3K inhibitor LY294002 showed anti-PEDV activity by blocking viral entry as well. Taken together, VAM possessed anti-PEDV properties against the entry stage of PEDV by inhibiting the macropinocytosis pathway by suppressing the PI3K/Akt pathway. VAM could be considered as a lead compound for the development of anti-PEDV drugs and may be used during the viral entry stage of PEDV infection.

Forsythoside A inhibits apoptosis and autophagy induced by infectious bronchitis virus through regulation of the PI3K/Akt/NF-κB pathway.

IMPORTANCE: Infectious bronchitis virus (IBV) is an acute and highly infectious viral disease that seriously endangered the development of the chicken industry. However, due to the limited effectiveness of commercial vaccines, there is an urgent need to develop safe and effective anti-IBV drugs. Forsythoside A (FTA) is a natural ingredient with wide pharmacological and biological activities, and it has been shown to have antiviral effects against IBV. However, the antiviral mechanism of FTA is still unclear. In this study, we demonstrated that FTA can inhibit cell apoptosis and autophagy induced by IBV infection by regulating the PI3K/AKT/NF-κB signaling pathway. This finding is important for exploring the role and mechanism of FTA in anti-IBV infection, indicating that FTA can be further studied as an anti-IBV drug.

Revealing Novel-Strain-Specific and Shared Epitopes of Infectious Bronchitis Virus Spike Glycoprotein Using Chemical Linkage of Peptides onto Scaffolds Precision Epitope Mapping.

The avian coronavirus, infectious bronchitis virus (IBV), is an economically important infectious disease affecting chickens, with a diverse range of serotypes found globally. The major surface protein, spike (S), has high diversity between serotypes, and amino acid differences in the S1 sub-unit are thought to be responsible for poor cross-protection afforded by vaccination. Here, we attempt to address this, by using epitope mapping technology to identify shared and serotype-specific immunogenic epitopes of the S glycoprotein of three major circulating strains of IBV, M41, QX, and 4/91, via CLIPS peptide arrays based on peptides from the S1 sub-units. The arrays were screened with sera from chickens immunised with recombinant IBV, based on Beau-R backbone expressing heterologous S, generated in two independent vaccination/challenge trials. The screening of sera from rIBV vaccination experiments led to the identification of 52 immunogenic epitopes on the S1 of M41, QX, and 4/91. The epitopes were assigned into six overlapping epitope binding regions. Based on accessibility and location in the hypervariable regions of S, three sequences, 25YVYYYQSAFRPPNGWHLQGGAYAVVNSTN54, 67TVGVIKDVYNQSVASI82, and 83AMTVPPAGMSWSVS96, were selected for further investigation, and synthetic peptide mimics were recognised by polyclonal sera. These epitopes may have the potential to contribute towards a broader cross-protective IBV vaccine.

Deletion of a 7-amino-acid region in the porcine epidemic diarrhea virus envelope protein induces higher type I and III interferon responses and results in attenuation in vivo.

Porcine epidemic diarrhea virus (PEDV) leads to enormous economic losses for the pork industry. However, the commercial vaccines failed to fully protect against the epidemic strains. Previously, the rCH/SX/2016-SHNXP strain with the entire E protein and the rCH/SX/2015 strain with the deletion of 7-amino-acid (7-aa) at positions 23-29 in E protein were constructed and rescued. The pathogenicity assay indicated that rCH/SX/2015 is an attenuated strain, but rCH/SX/2016-SHNXP belongs to the virulent strains. Then, the recombination PEDV (rPEDV-EΔaa23-aa29)strain with a 7-aa deletion in the E protein was generated, using the highly virulent rCH/SX/2016-SHNXP strain (rPEDV-Ewt) as the backbone. Compared with the rPEDV-Ewt strain, the release and infectivity of the rPEDV-EΔaa23-aa29 strain were significantly reduced in vitro, but stronger interferon (IFN) responses were triggered both in vitro and in vivo. The pathogenicity assay showed that the parental strain resulted in severe diarrhea (100%) and death (100%) in all piglets. Compared with the parental strain group, rPEDV-EΔaa23-aa29 caused lower mortality (33%) and diminished fecal PEDV RNA shedding. At 21 days, all surviving pigs were challenged orally with rPEDV-Ewt. No pigs died in the two groups. Compared with the mock group, significantly delayed and milder diarrhea and reduced fecal PEDV RNA shedding were detected in the rPEDV-EΔaa23-aa29 group. In conclusion, the deletion of a 7-aa fragment in the E protein (EΔaa23-aa29) attenuated PEDV but retained its immunogenicity, which can offer new ideas for the design of live attenuated vaccines and provide new insights into the attenuated mechanism of PEDV. IMPORTANCE Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets and remains a large challenge to the pork industry. Unfortunately, no safe and effective vaccines are available yet. The pathogenesis and molecular basis of the attenuation of PEDV remain unclear, which seriously hinders the development of PEDV vaccines. This study found that the rPEDV carrying EΔaa23-aa29 mutation in the E protein induced significantly higher IFN responses than the parental virus, partially attenuated, and remained immunogenic in piglets. For the first time, PEDV E was verified as an IFN antagonist in the infection context and identified as a virulence factor of PEDV. Our data also suggested that EΔaa23-aa29 mutation can be a good target for the development of live attenuated vaccines for PEDV and also provide new perspectives for the attenuated mechanism of PEDV.

A MERS-CoV antibody neutralizes a pre-emerging group 2c bat coronavirus.

The repeated emergence of zoonotic human betacoronaviruses (ß-CoVs) dictates the need for broad therapeutics and conserved epitope targets for countermeasure design. Middle East respiratory syndrome (MERS)-related coronaviruses (CoVs) remain a pressing concern for global health preparedness. Using metagenomic sequence data and CoV reverse genetics, we recovered a full-length wild-type MERS-like BtCoV/li/GD/2014-422 (BtCoV-422) recombinant virus, as well as two reporter viruses, and evaluated their human emergence potential and susceptibility to currently available countermeasures. Similar to MERS-CoV, BtCoV-422 efficiently used human and other mammalian dipeptidyl peptidase protein 4 (DPP4) proteins as entry receptors and an alternative DPP4-independent infection route in the presence of exogenous proteases. BtCoV-422 also replicated efficiently in primary human airway, lung endothelial, and fibroblast cells, although less efficiently than MERS-CoV. However, BtCoV-422 shows minor signs of infection in 288/330 human DPP4 transgenic mice. Several broad CoV antivirals, including nucleoside analogs and 3C-like/Mpro protease inhibitors, demonstrated potent inhibition against BtCoV-422 in vitro. Serum from mice that received a MERS-CoV mRNA vaccine showed reduced neutralizing activity against BtCoV-422. Although most MERS-CoV-neutralizing monoclonal antibodies (mAbs) had limited activity, one anti-MERS receptor binding domain mAb, JC57-11, neutralized BtCoV-422 potently. A cryo-electron microscopy structure of JC57-11 in complex with BtCoV-422 spike protein revealed the mechanism of cross-neutralization involving occlusion of the DPP4 binding site, highlighting its potential as a broadly neutralizing mAb for group 2c CoVs that use DPP4 as a receptor. These studies provide critical insights into MERS-like CoVs and provide candidates for countermeasure development.

Adenovirus-vectored PDCoV vaccines induce potent humoral and cellular immune responses in mice.

Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes severe watery diarrhea, vomiting, dehydration and high mortality in piglets, resulting in significant economic losses by the global pig industry. Recently, PDCoV has also shown the potential for cross-species transmission. However, there are currently few vaccine studies and no commercially available vaccines for PDCoV. Hence, here, two novel human adenovirus 5 (Ad5)-vectored vaccines expressing codon-optimized forms of the PDCoV spike (S) glycoprotein (Ad-PD-tPA-Sopt) and S1 glycoprotein (Ad-PD-oriSIP-S1opt) were constructed, and their effects were evaluated via intramuscular (IM) injection in BALB/c mice with different doses and times. Both vaccines elicited robust humoral and cellular immune responses; moreover, Ad-PD-tPA-Sopt-vaccinated mice after two IM injections with 108 infectious units (IFU)/mouse had significantly higher anti-PDCoV-specific neutralizing antibody titers. In contrast, the mice immunized with Ad-PD-tPA-Sopt via oral gavage (OG) did not generate robust systemic and mucosal immunity. Thus, IM Ad-PD-tPA-Sopt administration is a promising strategy against PDCoV and provides useful information for future animal vaccine development.

Efficacy of a plant-produced infectious bronchitis virus-like particle vaccine in specific pathogen-free chickens.

Infectious bronchitis (IB) Gammacoronavirus causes a highly contagious respiratory disease in chickens that is listed by the World Organisation for Animal Health (WOAH). Its high mutation ability has resulted in numerous variants against which the commercially available live or recombinant vaccines singly offer limited protection. Agrobacterium-mediated transient expression in Nicotiana benthamiana (tobacco) plants was used here to produce a virus-like particle (VLP) vaccine expressing a modified full-length IBV spike (S) protein of a QX-like IB variant. In a challenge study with the homologous live IB QX-like virus, VLP-vaccinated birds produced S protein-specific antibodies comparable to those produced by live-vaccinated birds seroconverting with mean geometric titers of 6.8 and 7.2 log2, respectively. The VLP-vaccinated birds had reduced oropharyngeal and cloacal viral shedding compared to an unvaccinated challenged control and were more protected against tracheal ciliostasis than the live-vaccinated birds. While the results appeared similar, plant-produced IB VLPs are safer, more affordable, easier to produce and update to antigenically match any emerging IB variant, making them a more suitable alternative to IBV control than live-attenuated vaccines.

[Prognostic scale for in-hospital mortality in patients with COVID-19 viral pneumonia]. / Escala pronóstica para mortalidad intrahospitalaria en pacientes con neumonía viral COVID-19.

Background: The COVID-19 pandemic represented a challenge in medical care. A tool would be very useful to establish the prognosis of in-hospital death that is reliable and can be applied to the Mexican population entitled to the IMSS. Objective: To propose a prognostic scale to stratify patients with viral pneumonia COVID-19 in the emergency services. Material and methods: A nested case-control study was conducted in a cohort of patients who were consecutively admitted to the emergency department with viral pneumonia COVID-19. The cases were those patients who died, and the controls were those who were discharged due to health improvement. An association analysis was performed between the variables with significant differences between groups. Subsequently, the association was adjusted using a multivariate logistic regression model, from which the prognostic scale was developed. Results: A total of 70 subjects with COVID-19 were included, 34 cases and 36 controls. Chronic diseases, smoking, severe pulmonary involvement diagnosed by tomography, leukocytosis, and pulse oximetry less than 80% with were associated with in-hospital mortality; Odds Ratio (OR) of >1.1. Vaccination was a protective factor (OR = 0.04, CI95%: 0.01-0.16). A score greater than 3 points on the prognostic scale predicts in-hospital mortality with a specificity of 0.86 and a sensitivity of 0.73. Conclusions: The proposed prognostic scale can be a useful tool in the classification of patients with COVID-19 viral pneumonia in the emergency room services of secondary care level Hospitals.

Introducción: la pandemia por COVID-19 representó un reto en la atención médica. Sería de gran utilidad una herramienta para establecer el pronóstico de muerte intrahospitalaria que sea confiable y pueda aplicarse a la población mexicana derechohabiente del Instituto Mexicano del Seguro Social. Objetivo: proponer una escala pronóstica para estratificar a los pacientes con neumonía viral por COVID-19 en los servicios de urgencias de los hospitales de segundo nivel. Material y métodos: se realizó un estudio de casos y controles anidado en una cohorte de pacientes adultos que fueron admitidos consecutivamente en el servicio de Urgencias con diagnóstico de neumonía viral por COVID-19. Los casos fueron aquellos pacientes que fallecieron y los controles aquellos que fueron egresados de la unidad por mejoría. Se realizó un análisis de asociación ente las variables con diferencias significativas entre ambos grupos, se ajustó la asociación mediante un modelo de regresión logística multivariada a partir del cual se elaboró la escala pronóstica. Resultados: se incluyeron en total 70 personas con COVID-19, 34 casos y 36 controles. Se asociaron a la mortalidad intrahospitalaria: las enfermedades crónicas, el tabaquismo, la afectación pulmonar severa diagnosticada por tomografía, la leucocitosis y la oximetría de pulso menor a 80% con una razón de Momios (RM) de > 1.1. La vacunación fue un factor protector (RM: 0.29, IC95%: 0.11-0.80). Un puntaje mayor a 3 puntos en la escala pronóstica predice la mortalidad intrahospitalaria (sensibilidad: 0.73, especificidad: 0.86). Conclusiones: la escala pronóstica propuesta puede ser una herramienta útil en la clasificación de los pacientes con neumonía viral por COVID-19 en los servicios de urgencias de los hospitales de segundo nivel de atención.

PTBP1 suppresses porcine epidemic diarrhea virus replication via inducing protein degradation and IFN production.

Porcine epidemic diarrhea virus (PEDV) causes severe morbidity and mortality among newborn piglets. It significantly threatens the porcine industry in China and around the globe. To accelerate the developmental pace of drugs or vaccines against PEDV, a deeper understanding of the interaction between viral proteins and host factors is crucial. The RNA-binding protein, polypyrimidine tract-binding protein 1 (PTBP1), is crucial for controlling RNA metabolism and biological processes. The present work focused on exploring the effect of PTBP1 on PEDV replication. PTBP1 was upregulated during PEDV infection. The PEDV nucleocapsid (N) protein was degraded through the autophagic and proteasomal degradation pathways. Moreover, PTBP1 recruits MARCH8 (an E3 ubiquitin ligase) and NDP52 (a cargo receptor) for N protein catalysis and degradation through selective autophagy. Furthermore, PTBP1 induces the host innate antiviral response via upregulating the expression of MyD88, which then regulates TNF receptor-associated factor 3/ TNF receptor-associated factor 6 expression and induces the phosphorylation of TBK1 and IFN regulatory factor 3. These processes activate the type Ⅰ IFN signaling pathway to antagonize PEDV replication. Collectively, this work illustrates a new mechanism related to PTBP1-induced viral restriction, where PTBP1 degrades the viral N protein and induces type Ⅰ IFN production to suppress PEDV replication.

El enigma del coronavirus - La variante BA.2.86 del SARS-CoV-2 - Lo nuevo sobre el COVID prolongado - Vacunas - Premios Nobel

El coronavirus ha continuado paseándose por el mundo con nuevas variantes, algunas consideradas de preocupación. Las hospitalizaciones aumentaron en algunas partes con la variante BA.2.86, especialmente en personas mayores obesas o con morbilidad, pero han disminuido, así como los fallecimientos. Las mujeres que gestaron mediante técnicas de reproducción asistida tuvieron similar morbilidad que quienes gestaron espontáneamente, pero con más resultados maternoperinatales adversos en aquellas de mayor edad, con embarazos múltiples, nuliparidad, índice de masa corporal >30. Los niños que nacieron al inicio de la pandemia mostraron un microbioma de diferente composición que quienes nacieron antes de la pandemia, lo que pudiera afectar su salud más adelante en la vida. Las personas que presentan COVID prolongado, un cuarto de ellas sufre secuelas en órganos y sistemas, con limitación y años perdidos de actividades, así como posibilidad de muerte prematura. El COVID prolongado ocurre más en mujeres entre 35 y 49 años y en quienes tienen menos ingresos económicos. Podrían desarrollar diabetes tipo 2. Habría interacciones directas entre el SARS-CoV-2 y proteínas mitocondriales esenciales en la producción de energía. El ARN viral ha sido detectado en lesiones ateroescleróticas coronarias y la espiga ha sido hallada en huesos del cráneo, meninges y cerebro. Las vacunas contra el coronavirus protegen a las gestantes y sus recién nacidos a través de transferencia placentaria y la lactancia. En la población, la inmunidad protectora de la infección y de las vacunas declina con el tiempo y se requerirá nueva vacunación con una regularidad aún no determinada.

The coronavirus has continued to move around the world with new variants, some of which are of concern. Hospitalizations increased in some places with the BA.2.86 variant, especially in obese or morbid elderly people, but have decreased, as have deaths. Women who gestated by assisted reproductive techniques had similar morbidity as those who gestated spontaneously, but with more adverse maternal-perinatal outcomes in those older, with multiple pregnancies, nulliparity, body mass index >30. Children born at the beginning of the pandemic showed a different microbiome composition than those born before the pandemic, which could affect their health later in life. Among people with long COVID, a quarter of them suffer organ and system sequelae, with limitation and lost years of activity, as well as the possibility of premature death. Long COVID occurs more in women between 35-49 years of age and in those with lower income. They could develop type 2 diabetes. There would be direct interactions between SARS-CoV-2 and mitochondrial proteins essential in energy production. Viral RNA has been detected in coronary atherosclerotic lesions and the spike has been found in skull bones, meninges and brain. Coronavirus vaccines protect pregnant women and their newborns through placental transfer and lactation. In the population, protective immunity from infection and vaccines declines over time and new vaccination will be required at an as yet undetermined regularity.

Enhancing immune protection against MERS-CoV: the synergistic effect of proteolytic cleavage sites and the fusion peptide and RBD domain targeting VLP immunization.

Introduction: The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic infectious virus that has caused significant outbreaks in the Middle East and beyond. Due to a highly mortality rate, easy transmission, and rapid spread of the MERS-CoV, it remains as a significant public health treat. There is currently no licensed vaccine available to protect against MERS-CoV. Methods: In this study, we investigated whether the proteolytic cleavage sites and fusion peptide domain of the MERS-CoV spike (S) protein could be a vaccine target to elicit the MERS-CoV S protein-specific antibody responses and confer immune protection against MERS-CoV infection. Our results demonstrate that immunization of the proteolytic cleavage sites and the fusion peptide domain using virus-like particle (VLP) induced the MERS-CoV S protein-specific IgG antibodies with capacity to neutralize pseudotyped MERS-CoV infection in vitro. Moreover, proteolytic cleavage sites and the fusion peptide VLP immunization showed a synergistic effect on the immune protection against MERS-CoV infection elicited by immunization with VLP expressing the receptor binding domain (RBD) of the S protein. Additionally, immune evasion of MERS-CoV RBD variants from anti-RBD sera was significantly controlled by anti-proteolytic cleavage sites and the fusion peptide sera. Conclusion and discussion: Our study demonstrates the potential of VLP immunization targeting the proteolytic cleavage sites and the fusion peptide and RBD domains of the MERS-CoV S protein for the development of effective treatments and vaccines against MERS-CoV and related variants.

Evaluation of protection and immunity induced by infectious bronchitis vaccines administered by oculonasal, spray or gel routes in commercial broiler chicks.

Broiler chicks' responses following combined IBV live attenuated Massachusetts and 793B strains through gel, spray or oculonasal (ON) vaccination routes were cross-compared. Subsequently, the responses following IBV M41 challenge of the unvaccinated and vaccinated groups were also assessed. Post-vaccination humoral and mucosal immune responses, alongside viral load kinetics in swabs and tissues, were determined using commercial ELISA assays, monoclonal antibody-based IgG and IgA ELISA assays and qRT-PCR respectively. After challenged with IBV-M41 strain, humoral and mucosal immune responses, ciliary protection, viral load kinetics, and immune gene mRNA transcriptions between the three vaccination methods were examined and compared. Findings showed that post-vaccinal humoral and mucosal immune responses were similar in all three vaccination methods. Post vaccinal viral load kinetics is influenced by method of administration. The viral load peaked in the ON group within the tissues and the OP/CL swabs in the first and third weeks respectively. Following M41 challenge, ciliary protection and mucosal immune responses were not influenced by vaccination methods as all three methods offered equal ciliary protection. Immune gene mRNA transcriptions varied by vaccination methods. Significant up-regulation of MDA5, TLR3, IL-6, IFN-α and IFN-ß genes were recorded for ON method. For both spray and gel methods, significant up-regulation of only MDA5 and IL-6 genes were noted. The spray and gel-based vaccination methods gave equivalent levels of ciliary protection and mucosal immunity to M41 virulent challenge comparable to those provided by the ON vaccination. Analysis of viral load and patterns of immune gene transcription of the vaccinated-challenged groups revealed high similarity between turbinate and choanal cleft tissues compared to HG and trachea. With regards to immune gene mRNA transcription, for all the vaccinated-challenged groups, similar results were found except for IFN-α, IFN-ß and TLR3, which were up-regulated only in ON compared to gel and spray vaccination methods.

Coronavirus Porcine Epidemic Diarrhea Virus Utilizes Chemokine Interleukin-8 to Facilitate Viral Replication by Regulating Ca2+ Flux.

Chemokine production by epithelial cells is crucial for neutrophil recruitment to sites of inflammation during viral infection. However, the effect of chemokine on epithelia and how chemokine is involved in coronavirus infection remains to be fully understood. Here, we identified an inducible chemokine interleukin-8 (CXCL8/IL-8), which could promote coronavirus porcine epidemic diarrhea virus (PEDV) infection in African green monkey kidney epithelial cells (Vero) and Lilly Laboratories cell-porcine kidney 1 epithelial cells (LLC-PK1). IL-8 deletion restrained cytosolic calcium (Ca2+), whereas IL-8 stimulation improved cytosolic Ca2+. The consumption of Ca2+ restricted PEDV infection. PEDV internalization and budding were obvious reductions when cytosolic Ca2+ was abolished in the presence of Ca2+ chelators. Further study revealed that the upregulated cytosolic Ca2+ redistributes intracellular Ca2+. Finally, we identified that G protein-coupled receptor (GPCR)-phospholipase C (PLC)-inositol trisphosphate receptor (IP3R)-store-operated Ca2+ (SOC) signaling was crucial for enhancive cytosolic Ca2+ and PEDV infection. To our knowledge, this study is the first to uncover the function of chemokine IL-8 during coronavirus PEDV infection in epithelia. PEDV induces IL-8 expression to elevate cytosolic Ca2+, promoting its infection. Our findings reveal a novel role of IL-8 in PEDV infection and suggest that targeting IL-8 could be a new approach to controlling PEDV infection. IMPORTANCE Coronavirus porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric coronavirus that caused severe economic losses worldwide, and more effort is needed to develop economical and efficient vaccines to control or eliminate this disease. The chemokine interleukin-8 (CXCL8/IL-8) is indispensable for the activation and trafficking of inflammatory mediators and tumor progression and metastasis. This study evaluated the effect of IL-8 on PEDV infection in epithelia. We found that IL-8 expression improved cytosolic Ca2+ in epithelia, facilitating PEDV rapid internalization and egress. G protein-coupled receptor (GPCR)-phospholipase C (PLC)-inositol trisphosphate receptor (IP3R)-SOC signaling was activated by IL-8, releasing the intracellular Ca2+ stores from endoplasmic reticulum (ER). These findings provide a better understanding of the role of IL-8 in PEDV-induced immune responses, which will help develop small-molecule drugs for coronavirus cure.

Recombinant human adenovirus type 5 based vaccine candidates against GIIa- and GIIb-genotype porcine epidemic diarrhea virus induce robust humoral and cellular response in mice.

Porcine epidemic diarrhea virus (PEDV) is a porcine enteropathogenic coronavirus causing severe watery diarrhea, vomiting, dehydration, and death in piglets. However, most commercial vaccines are developed based on the GI genotype strains, and have poor immune protection against the currently dominant GII genotype strains. Therefore, four novel replication-deficient human adenovirus 5-vectored vaccines expressing codon-optimized forms of the GIIa and GIIb strain spike and S1 glycoproteins were constructed, and their immunogenicity was evaluated in mice by intramuscular (IM) injection. All the recombinant adenoviruses generated robust immune responses, and the immunogenicity of recombinant adenoviruses against the GIIa strain was stronger than that of recombinant adenoviruses against the GIIb strain. Moreover, Ad-XT-tPA-Sopt-vaccinated mice elicited optimal immune effects. In contrast, mice immunized with Ad-XT-tPA-Sopt by oral gavage did not induce strong immune responses. Overall, IM administration of Ad-XT-tPA-Sopt is a promising strategy against PEDV, and this study provides useful information for developing viral vector-based vaccines.

A novel S2-derived peptide-based ELISA for broad detection of antibody against infectious bronchitis virus.

Avian infectious bronchitis (IB) is a highly contagious disease caused by infectious bronchitis virus (IBV). Vaccination is an effective approach for controlling IBV. Therefore, reliable immune monitoring for IB is critical for poultry. In this study, a novel peptide derived from S2 protein was used to develop an enzyme-linked immunosorbent assay (ELISA) for the detection of broadly cross-reactive antibodies against IBV. The peptide-based ELISA (pELISA) showed good specificity and sensitivity in detecting IBV antibodies against different serotypes. A semilogarithmic regression method for determining IBV antibody titers was also established. Antibody titers detected by pELISA and calculated with this equation were statistically similar to those evaluated by indirect fluorescence assay (IFA). Moreover, the comparison analysis showed a 96.07% compatibility between the pELISA and IDEXX ELISA. All these data demonstrate that the pELISA generated here can be as a rapid and reliable serological surveillance tool for monitoring IBV infection or vaccination.

Subunit vaccines with a saponin-based adjuvant boost humoral and cellular immunity to MERS coronavirus.

Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks have constituted a public health issue with drastic mortality higher than 34%, necessitating the development of an effective vaccine. During MERS-CoV infection, the trimeric spike protein on the viral envelope is primarily responsible for attachment to host cellular receptor, dipeptidyl peptidase 4 (DPP4). With the goal of generating a protein-based prophylactic, we designed a subunit vaccine comprising the recombinant S1 protein with a trimerization motif (S1-Fd) and examined its immunogenicity and protective immune responses in combination with various adjuvants. We found that sera from immunized wild-type and human DPP4 transgenic mice contained S1-specific antibodies that can neutralize MERS-CoV infection in susceptible cells. Vaccination with S1-Fd protein in combination with a saponin-based QS-21 adjuvant provided long-term humoral as well as cellular immunity in mice. Our findings highlight the significance of the trimeric S1 protein in the development of MERS-CoV vaccines and offer a suitable adjuvant, QS-21, to induce robust and prolonged memory T cell response.

Percepción del riesgo de desastres en una comunidad vulnerable del Distrito de San Miguelito, Panamá

Introducción: Los desastres causan daños al ambiente y a las personas, impactando en la salud, condición de vida y paz emocional, lo que requiere una comunidad conocedora de las características territoriales, las incidencias de los efectos ambientales, los peligros sanitarios y las competencias intersectoriales ante un desastre. Objetivo: Identificar la percepción del riesgo de desastres en una comunidad vulnerable.Metodología: Estudio descriptivo transversal con un universo estudio de 304 viviendas con jefes de hogar de la comunidad Villa Esperanza del Distrito de San Miguelito. Se consideró la percepción del riesgo ambiental y epidemiológico. Fue elaborado un cuestionario con preguntas abiertas y cerradas para datos cualitativos y cuantitativos. Se aplicaron medidas de tendencia central presentando los datos en frecuencias relativas y absolutas en escala nominal, ordinal y en mapas georeferenciados.Resultados: Aceptaron participar 286 jefes de hogar. El 53.8% no percibe el riesgo ambiental y el 46.2% si lo percibe. El riesgo epidemiológico no es percibido por el 79.0% de los jefes de hogar y el 21.0% sí lo percibe. Considerando las enfermedades prevenibles por vacunas e infecciones por Coronavirus (COVID -19), el 44.4% indicó, que algún miembro del hogar padeció está enfermedad. Conclusión: Se identificó la subestimación del riesgo o negación implícita del riesgo y ausencia de linealidad en la percepción de riesgo de desastre.Se hace necesario la promoción y prevención para conocimiento, control preventivo y preparación en gestión de riesgo de desastres en la comunidad Villa Esperanza. (provisto por Infomedic International)

Introduction: Disasters cause damage to the environment and people, impacting health, living condition and emotional peace, which requires a community knowledgeable about territorial characteristics, incidences of environmental effects, health hazards and intersectoral competencies in the face of a disaster. Objective: To identify the perception of disaster risk in a vulnerable community.Methodology: Cross-sectional descriptive study with a study universe of 304 households with heads of household in the Villa Esperanza community of the District of San Miguelito. The perception of environmental and epidemiological risk was considered. A questionnaire was prepared with open and closed questions for qualitative and quantitative data. Measures of central tendency were applied, presenting the data in relative and absolute frequencies on a nominal and ordinal scale and on geo-referenced maps.Results: 286 heads of household agreed to participate. 53.8% do not perceive environmental risk. A total of 53.8% did not perceive environmental risk and 46.2% did. Epidemiological risk is not perceived by 79.0% of the heads of household and 21.0% do perceive it. Considering vaccine-preventable diseases and Coronavirus infections (COVID-19), 44.4% indicated that a member of the household had suffered from this disease. Conclusion: Underestimation of risk or implicit denial of risk and lack of linearity in the perception of disaster risk were identified, making it necessary to promote and prevent knowledge, preventive control and preparation for disaster risk management in the Villa Esperanza community. (provided by Infomedic International)