Chestnut inner shell extract inhibits viral entry of porcine epidemic diarrhea virus and other coronaviruses in vitro.

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes acute diarrhea in suckling piglets. Although vaccines are able to reduce the incidence of PEDV infection, outbreaks of PEDV continue to be reported worldwide and cause serious economic losses in the swine industry. To identify novel antiviral sources, we identified the chestnut (Castanea crenata) inner shell (CIS) as a natural material with activity against PEDV infection in vitro. The ethanol fractions of CIS extracts potently inhibited PEDV infection with an IC90 of 30 µg/ml. Further investigation of the virus lifecycle demonstrated that CIS extract particularly targeted the early stages of PEDV infection by blocking viral attachment and membrane fusion at rates of 80~90%. In addition, CIS extract addition reduced the viral entry of other members of the Coronaviridae family. Our data demonstrated that CIS extract inhibited PEDV infection by blocking cell entry in vitro and suggest that CIS extract is a new prophylactic and therapeutic agent against PEDV and other coronavirus infections.

Comparison of safety and efficacy between therapeutic or intermediate versus prophylactic anticoagulation for thrombosis in COVID-19 patients: a systematic review and meta-analysis.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) infections often have macrovascular or microvascular thrombosis and inflammation, which are known to be associated with a poor prognosis. Heparin has been hypothesized that administration of heparin with treatment dose rather than prophylactic dose for prevention of deep vein thrombosis in COVID-19 patients. METHODS: Studies comparing therapeutic or intermediate anticoagulation with prophylactic anticoagulation in COVID-19 patients were eligible. Mortality, thromboembolic events, and bleeding were the primary outcomes. PubMed, Embase, the Cochrane Library, and KMbase were searched up to July 2021. A meta-analysis was performed using random-effect model. Subgroup analysis was conducted according to disease severity. RESULTS: Six randomized controlled trials (RCTs) with 4,678 patients and four cohort studies with 1,080 patients were included in this review. In the RCTs, the therapeutic or intermediate anticoagulation was associated with significant reductions in the occurrence of thromboembolic events (5 studies, n=4,664; relative risk [RR], 0.72; P=0.01), and a significant increase in bleeding events (5 studies, n=4,667; RR, 1.88; P=0.004). In the moderate patients, therapeutic or intermediate anticoagulation was more beneficial than prophylactic anticoagulation in terms of thromboembolic events, but showed significantly higher bleeding events. In the severe patients, the incidence of thromboembolic and bleeding events in the therapeutic or intermediate. CONCLUSIONS: The study findings suggest that prophylactic anticoagulant treatment should be used in patients with moderate and severe COVID-19 infection groups. Further studies are needed to determine more individualized anticoagulation guidance for all COVID-19 patients.

Two Years of Experience and Methodology of Korean COVID-19 Living Clinical Practice Guideline Development.

BACKGROUND: In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration. METHODS: The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations. RESULTS: An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3-4 months. CONCLUSION: We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media. Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics.

Evaluation of Four Rapid Antigen Tests for the Detection of SARS-CoV-2 Infection with Nasopharyngeal Swabs.

Owing to the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the capacity of testing systems based on the gold standard real-time reverse transcription-polymerase chain reaction (rRT-PCR) is limited. Rapid antigen tests (RATs) can substantially contribute to the prevention of community transmission, but their further assessment is required. Here, using 1503 nasopharyngeal swabs, we compared the diagnostic performance of four RAT kits (Abbott Panbio™ COVID-19 Ag Rapid Test, SD Biosensor Standard™ Q COVID-19 Ag Test, Humasis COVID-19 Ag Test, and SG Medical Acrosis COVID-19 Ag Test) to the cycle threshold (Ct) values obtained from rRT-PCR. The precision values, area under the curve values, SARS-CoV-2 variant detection ability, and non-SARS-CoV-2 specificity of all four kits were similar. An assay using the Acrosis kit had a significantly better positive detection rate with a higher recall value and cut-off value than that using the other three RAT kits. During the current COVID-19 pandemic, the Acrosis kit is an effective tool to prevent the spread of SARS-CoV-2 in communities.

Resistance of Field-Isolated Porcine Epidemic Diarrhea Virus to Interferon and Neutralizing Antibody.

Variant porcine epidemic diarrhea virus (PEDV), belonging to the genogroup G2b, has higher pathogenicity and mortality than classical PEDV, belonging to the genogroup G1a. To understand the pathogenesis of the G2b PEDV, we examined the resistance of the G2b PEDV to interferon (IFN) and neutralizing antibodies, which are important for controlling PEDV infection. We found that the G2b PEDV showed higher resistance to IFN than G1a PEDV. The G1a PEDV could replicate in IFN-deficient Vero cells, but not in IFN-releasing porcine alveolar macrophages, whereas the G2b PEDV showed similar infectivity in both types of cells. We also found that G2b PEDV was not effectively blocked by neutralizing antibodies, unlike G1a PEDV, suggesting differences in the antigenicity of the two strains. These results provide an understanding of the occurrence of variant PEDV and its pathogenesis.

Efficacy and safety of prone position in COVID-19 patients with respiratory failure: a systematic review and meta-analysis.

BACKGROUND: Prone position has already been demonstrated to improve survival in non-COVID acute respiratory distress syndrome and has been widely performed in COVID-19 patients with respiratory failure, both in non-intubated and intubated patients. However, the beneficial effect of the prone position in COVID-19 pneumonia still remains controversial. Therefore, we aimed to evaluate the effectiveness and safety of the prone position compared with the non-prone in non-intubated and intubated COVID-19 patients, respectively. METHODS: We searched the MEDLINE, EMBASE, and Cochrane databases, as well as one Korean domestic database, on July 9, 2021, and updated the search 9 times to September 14, 2022. Studies that compared prone and non-prone positions in patients with COVID-19 were eligible for inclusion. The primary outcomes were mortality, need for intubation, and adverse events. RESULTS: Of the 1259 records identified, 9 randomized controlled trials (RCTs) and 23 nonrandomized studies (NRSs) were eligible. In the non-intubated patients, the prone position reduced the intubation rate compared with the non-prone position in 6 RCTs (n = 2156, RR 0.81, P = 0.0002) and in 18 NRSs (n = 3374, RR 0.65, P = 0.002). In the subgroup analysis according to the oxygen delivery method, the results were constant only in the HFNC or NIV subgroup. For mortality, RCTs reported no difference between prone and non-prone groups, but in NRSs, the prone position had a significant advantage in mortality [18 NRSs, n = 3361, relative risk (RR) 0.56, P < 0.00001] regardless of the oxygen delivery methods shown in the subgroup analysis. There was no RCT for intubated patients, and mortality did not differ between the prone and non-prone groups in NRSs. Adverse events reported in both the non-intubated and intubated groups were mild and similar between the prone and non-intubated groups. CONCLUSION: For non-intubated patients with COVID-19, prone positioning reduced the risk of intubation, particularly in patients requiring a high-flow oxygen system. However, the survival benefit was unclear between the prone and non-prone groups. There was insufficient evidence to support the beneficial effects of prone positioning in intubated patients. Trial registration This study was registered in the Prospective Register of Systematic Reviews on February 16, 2022 (Registration No.: CRD42022311150 ).

Early intubation and clinical outcomes in patients with severe COVID-19: a systematic review and meta-analysis.

BACKGROUND: Evidence regarding the timing of the application of mechanical ventilation among patients with severe coronavirus disease (COVID-19) is insufficient. This systematic review and meta-analysis aimed to evaluate the effectiveness of early intubation compared to late intubation in patients with severe and critical COVID-19. METHODS: For this study, we searched the MEDLINE, EMBASE, and Cochrane databases as well as one Korean domestic database on July 15, 2021. We updated the search monthly from September 10, 2021 to February 10, 2022. Studies that compared early intubation with late intubation in patients with severe COVID-19 were eligible for inclusion. Relative risk (RR) and mean difference (MD) were calculated as measures of effect using the random-effects model for the pooled estimates of in-hospital mortality, intensive care unit (ICU) length of stay (LOS), duration of mechanical ventilation (MV), hospital LOS, ICU-free days, and ventilator-free days. Subgroup analysis was performed based on the definition of early intubation and the index time. To assess the risk of bias in the included studies, we used the Risk of Bias Assessment tool for Non-randomized studies 2.0. RESULTS: Of the 1523 records identified, 12 cohort studies, involving 2843 patients with severe COVID-19 were eligible. There were no differences in in-hospital mortality (8 studies, n = 795; RR 0.91, 95% CI 0.75-1.10, P = 0.32, I2 = 33%), LOS in the ICU (9 studies, n = 978; MD -1.77 days, 95% CI -4.61 to 1.07 days, P = 0.22, I2 = 78%), MV duration (9 studies, n = 1,066; MD -0.03 day, 95% CI -1.79 to 1.72 days, P = 0.97, I2 = 49%), ICU-free days (1 study, n = 32; 0 day vs. 0 day; P = 0.39), and ventilator-free days (4 studies, n = 344; MD 0.94 day, 95% CI -4.56 to 6.43 days, P = 0.74, I2 = 54%) between the early and late intubation groups. However, the early intubation group had significant advantage in terms of hospital LOS (6 studies, n = 738; MD -4.32 days, 95% CI -7.20 to -1.44 days, P = 0.003, I2 = 45%). CONCLUSION: This study showed no significant difference in both primary and secondary outcomes between the early intubation and late intubation groups. Trial registration This study was registered in the Prospective Register of Systematic Reviews on 16 February, 2022 (registration number CRD42022311122).

Performance Analysis of Self-Collected Nasal and Oral Swabs for Detection of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third highly pathogenic human coronavirus and is rapidly transmitted by infected individuals regardless of their symptoms. During the COVID-19 pandemic, owing to the dearth of skilled healthcare workers (HCWs) to collect samples for early diagnosis, self-collection emerged as a viable alternative. To evaluate the reliability of self-collection, we compared the virus detection rate using 3990 self-collected swabs and HCW-collected swabs, procured from the same individuals and collected immediately after the self-collection. The results of multiplex reverse-transcription quantitative polymerase chain reaction revealed that the viral load in the HCW-collected swabs was marginally (18.4–28.8 times) higher than that in self-collected swabs. Self-collection showed no significant difference in sensitivity and specificity from HCW-collection (κ = 0.87, McNemar’s test;p = 0.19), indicating a comparable performance. These findings suggest that self-collected swabs are acceptable substitutes for HCW-collected swabs, and that their use improved the specimen screening efficiency and reduced the risk of SARS-CoV-2 infection among HCWs during and after the COVID-19 pandemic.

Performance Analysis of Self-Collected Nasal and Oral Swabs for Detection of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third highly pathogenic human coronavirus and is rapidly transmitted by infected individuals regardless of their symptoms. During the COVID-19 pandemic, owing to the dearth of skilled healthcare workers (HCWs) to collect samples for early diagnosis, self-collection emerged as a viable alternative. To evaluate the reliability of self-collection, we compared the virus detection rate using 3990 self-collected swabs and HCW-collected swabs, procured from the same individuals and collected immediately after the self-collection. The results of multiplex reverse-transcription quantitative polymerase chain reaction revealed that the viral load in the HCW-collected swabs was marginally (18.4-28.8 times) higher than that in self-collected swabs. Self-collection showed no significant difference in sensitivity and specificity from HCW-collection (κ = 0.87, McNemar's test; p = 0.19), indicating a comparable performance. These findings suggest that self-collected swabs are acceptable substitutes for HCW-collected swabs, and that their use improved the specimen screening efficiency and reduced the risk of SARS-CoV-2 infection among HCWs during and after the COVID-19 pandemic.

Chestnut inner shell extract inhibits viral entry of porcine epidemic diarrhea virus and other coronaviruses in vitro

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes acute diarrhea in suckling piglets. Although vaccines are able to reduce the incidence of PEDV infection, outbreaks of PEDV continue to be reported worldwide and cause serious economic losses in the swine industry. To identify novel antiviral sources, we identified the chestnut (Castanea crenata) inner shell (CIS) as a natural material with activity against PEDV infection in vitro. The ethanol fractions of CIS extracts potently inhibited PEDV infection with an IC90 of 30 μg/ml. Further investigation of the virus lifecycle demonstrated that CIS extract particularly targeted the early stages of PEDV infection by blocking viral attachment and membrane fusion at rates of 80~90%. In addition, CIS extract addition reduced the viral entry of other members of the Coronaviridae family. Our data demonstrated that CIS extract inhibited PEDV infection by blocking cell entry in vitro and suggest that CIS extract is a new prophylactic and therapeutic agent against PEDV and other coronavirus infections.

Furin cleavage is required for swine acute diarrhea syndrome coronavirus spike protein-mediated cell - cell fusion.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) was reported in China in 2017 and is a causative agent of porcine enteric disease. Recent studies indicate that cells from various hosts are susceptible to SADS-CoV, suggesting the zoonotic potential of this virus. However, little is known about the mechanisms through which this virus enters cells. In this study, we investigated the role of furin in SADS-CoV spike (S)-mediated cell - cell fusion and entry. We found that the SADS-CoV S protein induced the fusion of various cells. Cell - cell fusion was inhibited by the proprotein convertase inhibitor dec-RVKR-cmk, and between cells transfected with mutant S proteins resistant to furin cleavage. These findings revealed that furin-induced cleavage of the SADS-CoV S protein is required for cell - cell fusion. Using mutagenesis analysis, we demonstrated that furin cleaves the SADS-CoV S protein near the S1/S2 cleavage site, 446RYVR449 and 543AVRR546. We used pseudotyped viruses to determine whether furin-induced S cleavage is also required for viral entry. Pseudotyped viruses expressing S proteins with a mutated furin cleavage site could be transduced into target cells, indicating that furin-induced cleavage is not required for pseudotyped virus entry. Our data indicate that S cleavage is critical for SADS-CoV S-mediated cell - cell fusion and suggest that furin might be a host target for SADS-CoV antivirals.

A chimeric MERS-CoV virus-like particle vaccine protects mice against MERS-CoV challenge.

BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory disease in humans, with a case fatality rate of approximately 35%, thus posing a considerable threat to public health. The lack of approved vaccines or antivirals currently constitutes a barrier in controlling disease outbreaks and spread. METHODS: In this study, using a mammalian expression system, which is advantageous for maintaining correct protein glycosylation patterns, we constructed chimeric MERS-CoV virus-like particles (VLPs) and determined their immunogenicity and protective efficacy in mice. RESULTS: Western blot and cryo-electron microscopy analyses demonstrated that MERS-CoV VLPs were efficiently produced in cells co-transfected with MERS-CoV spike (S), envelope, membrane and murine hepatitis virus nucleocapsid genes. We examined their ability as a vaccine in a human dipeptidyl peptidase 4 knock-in C57BL/6 congenic mouse model. Mice immunized with MERS VLPs produced S-specific antibodies with virus neutralization activity. Furthermore, MERS-CoV VLP immunization provided complete protection against a lethal challenge with mouse-adapted MERS-CoV and improved virus clearance in the lung. CONCLUSIONS: Overall, these data demonstrate that MERS-CoV VLPs have excellent immunogenicity and represent a promising vaccine candidate.

Correlation between Stress and Anxiety to Viral Epidemics (SAVE) and Burnout among Korean Dental Hygienists during the COVID-19 Pandemic: A Cross-Sectional Study.

This study aimed to investigate the correlations among Stress and Anxiety to Viral Epidemics (SAVE), job stress (JS), and burnout among Korean dental hygienists during the COVID-19 pandemic and to identify the moderating effect of JS. As a cross-sectional study, a self-reporting questionnaire was used to survey 204 clinical dental hygienists to measure the levels of SAVE, JS, and burnout, along with their demographic characteristics as the control variables. Pearson correlation analysis and hierarchical multiple regression analysis were performed to analyse the correlations among burnout, SAVE, and JS, including the moderating effect of JS. With education level and subjective health controlled, JS (ß = 1.05, p < 0.001), SAVE (ß = 0.69, p = 0.020) and the interaction between SAVE and JS (ß = -0.93, p = 0.050) were identified as significant influencing factors of burnout. The adjusted explanatory power of the model was found to be 52.4%. In summary, both SAVE and JS were significant influencing factors of burnout among dental hygienists, while a moderating effect of JS was also identified. Therefore, it is necessary to create a work environment that can relieve SAVE and JS to reduce burnout among dental hygienists.

Evaluation of Three Automated Extraction Systems for the Detection of SARS-CoV-2 from Clinical Respiratory Specimens.

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is highly contagious and causes coronavirus disease 2019 (COVID-19). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is the most accurate and reliable molecular assay to detect active SARS-CoV-2 infection. However, a rapid increase in test subjects has created a global bottleneck in testing capacity. Given that efficient nucleic acid extraction greatly affects reliable and accurate testing results, we compared three extraction platforms: MagNA Pure 96 DNA and Viral NA Small Volume kit on MagNA Pure 96 (Roche, Basel, Switzerland), careGENETM Viral/Pathogen HiFi Nucleic Acid Isolation kit (WELLS BIO Inc., Seoul, Korea) on KingFisher Flex (Thermo Fisher Scientific, Rocklin, CA, USA), and SGRespiTM Pure kit (Seegene Inc., Seoul, Korea) on Maelstrom 9600 (Taiwan Advanced Nanotech Inc., Taoyuan, Taiwan). RNA was extracted from 245 residual respiratory specimens from the different types of samples (i.e., NPS, sputum, and saliva) using three different kits. The 95% limits of detection of median tissue culture infectious dose per milliliter (TCID50/mL) for the MagNA Pure 96, KingFisher Flex, and Maelstrom 9600 were 0.37-3.15 × 101, 0.41-3.62 × 101, and 0.33-1.98 × 101, respectively. The KingFisher Flex platform exhibited 99.2% sensitivity and 100% specificity, whereas Maelstrom 9600 exhibited 98.3-100% sensitivity and 100% specificity. Bland-Altman analysis revealed a 95.2% concordance between MagNA Pure 96 and KingFisher Flex and 95.4% concordance between MagNA Pure 96 and Maelstrom 9600, indicating that all three platforms provided statistically reliable results. This suggests that two modifying platforms, KingFisher Flex and Maelstrom 9600, are accurate and scalable extraction platforms for large-scale SARS-CoV-2 clinical detection and could help the management of COVID-19 patients.

Effect of Oral Health Education Using a Mobile App (OHEMA) on the Oral Health and Swallowing-Related Quality of Life in Community-Based Integrated Care of the Elderly: A Randomized Clinical Trial.

This study investigated the effect of oral health education using a mobile app (OHEMA) on the oral health and swallowing-related quality of life (SWAL-QoL) of the elderly population in a community-based integrated care project (CICP). Forty elderly individuals in the CICP were randomized into intervention and control groups. OHEMA provided information on customized oral health care management, oral exercises, and intraoral and extraoral massage methods for 50 min/session, once a week, for 6 weeks. Pre- and post-intervention surveys assessed the unstimulated salivary flow rate, subjective oral dryness, tongue pressure, and SWAL-QoL, which were analyzed using ANCOVA and repeated measures ANOVA. In the intervention group, tongue pressure increased significantly from pre- (17.75) to post-intervention (27.24) (p < 0.001), and subjective oral dryness decreased from pre- (30.75) to post-intervention (18.50). The unstimulated salivary flow rate had a higher mean score in the intervention group (7.19) than in the control group (5.04) (p < 0.001). The SWAL-QoL significantly improved from pre- (152.10) to post-intervention (171.50) in the intervention group (p < 0.001) but did not change significantly in the control group (p > 0.05). OHEMA appears to be a useful tool for oral health education for the elderly as it improved the SWAL-QoL, with increased tongue pressure and reduced oral dryness.

Revised Korean Society of Infectious Diseases/National Evidence-based Healthcarea Collaborating Agency Guidelines on the Treatment of Patients with COVID-19.

Despite the global effort to mitigate the spread, coronavirus disease 2019 (COVID-19) has become a pandemic that took more than 2 million lives. There are numerous ongoing clinical studies aiming to find treatment options and many are being published daily. Some effective treatment options, albeit of variable efficacy, have been discovered. Therefore, it is necessary to develop an evidence-based methodology, to continuously check for new evidence, and to update recommendations accordingly. Here we provide guidelines on pharmaceutical treatment for COVID-19 based on the latest evidence.

Assay System for Simultaneous Detection of SARS-CoV-2 and Other Respiratory Viruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggers disease with nonspecific symptoms that overlap those of infections caused by other seasonal respiratory viruses (RVs), such as the influenza virus (Flu) or respiratory syncytial virus (RSV). A molecular assay for accurate and rapid detection of RV and SARS-CoV-2 is crucial to manage these infections. Here, we compared the analytical performance and clinical reliability of Allplex™ SARS-CoV-2/FluA/FluB/RSV (SC2FabR; Seegene Inc., Seoul, South Korea) kit with those of four commercially available RV detection kits. Upon testing five target viral strains (SARS-CoV-2, FluA, FluB, RSV A, and RSV B), the analytical performance of SC2FabR was similar to that of the other kits, with no significant difference (p ≥ 0.78) in z-scores. The efficiency of SC2FabR (E-value, 81-104%) enabled reliable SARS-CoV-2 and seasonal RV detection in 888 nasopharyngeal swab specimens processed using a fully automated nucleic acid extraction platform. Bland-Altman analyses revealed an agreement value of 95.4% (SD ± 1.96) for the kits, indicating statistically similar results for all five. In conclusion, SC2FabR is a rapid and accurate diagnostic tool for both SARS-CoV-2 and seasonal RV detection, allowing for high-throughput RV analysis with efficiency comparable to that of commercially available kits. This can be used to help manage respiratory infections in patients during and after the coronavirus disease 2019 pandemic.

Immunization with porcine epidemic diarrhea virus harbouring Fc domain of IgG enhances antibody production in pigs.

Background: Outbreaks of porcine epidemic diarrhea virus (PEDV) infection have re-emerged and spread rapidly worldwide, resulting in significant economic losses. Vaccination is the best way to prevent PEDV infection in young piglets.Objective: To enhance the efficacy of an inactivated vaccine against PEDV, we evaluated the adjuvant properties of Fc domain of IgG.Methods: Fifteen crossbred gilts (180 ∼ 210 days old) were used. Five pigs in group 1 were intramuscularly vaccinated twice at 4 weeks and 2 weeks prior to farrowing with 106 TCID50 of inactivated PEDV. Five pigs in group 2 were intramuscularly vaccinated twice at 4 weeks and 2 weeks prior to farrowing with 106 TCID50 of inactivated PEDV-sFc. Five pigs in group 3 were not vaccinated and served as negative controls. Serum samples were collected at farrowing and subjected to ELISA, a serum neutralizing (SN) test, and a cytokine assay. Statistical analysis was performed by a two-tailed unpaired t-test.Results: Vero cells expressing swine IgG Fc on its surface was established. When PEDV was propagated in the cells expressing the swine Fc, PEDV virion incorporated the Fc. Immunization of pigs with inactivated PEDV harbouring Fc induced significantly higher antibody production against PEDV, comparing to the immunization with normal inactivated PEDV. In addition, we observed significantly increased IFN-γ levels in sera.Conclusion: Our results indicate that Fc molecule facilitate immune responses and PEDV harbouring Fc molecule could be a possible vaccine candidate. However, a challenge experiment would be needed to investigate the protective efficacy of PEDV harbouring Fc.