Toward a Radically Simple Multi-Modal Nasal Spray for Preventing Respiratory Infections.

Nasal sprays for pre-exposure prophylaxis against respiratory infections show limited protection (20-70%), largely due to their single mechanism of action-either neutralizing pathogens or blocking their entry at the nasal lining, and a failure to maximize the capture of respiratory droplets, allowing them to potentially rebound and reach deeper airways. This report introduces the Pathogen Capture and Neutralizing Spray (PCANS), which utilizes a multi-modal approach to enhance efficacy. PCANS coats the nasal cavity, capturing large respiratory droplets from the air, and serving as a physical barrier against a broad spectrum of viruses and bacteria, while rapidly neutralizing them with over 99.99% effectiveness. The formulation consists of excipients identified from the FDA's Inactive Ingredient Database and Generally Recognized as Safe list to maximize efficacy for each step in the multi-modal approach. PCANS demonstrates nasal retention for up to 8 hours in mice. In a severe Influenza A mouse model, a single pre-exposure dose of PCANS leads to a >99.99% reduction in lung viral titer and ensures 100% survival, compared to 0% in the control group. PCANS suppresses pathological manifestations and offers protection for at least 4 hours. This data suggest PCANS as a promising daily-use prophylactic against respiratory infections.

SARS-CoV-2 Infection Enhances Humoral Immune Response in Vaccinated Liver Transplant Recipients.

In the spring of 2020, the SARS-CoV-2 pandemic presented a formidable challenge to national and global healthcare systems. Immunocompromised individuals or those with relevant pre-existing conditions were particularly at risk of severe coronavirus disease 2019 (COVID-19). Thus, understanding the immunological processes in these patient groups is crucial for current research. This study aimed to investigate humoral immunity following vaccination and infection in liver transplant recipients. Humoral immunity analysis involved measuring IgG against the SARS-CoV-2 spike protein (anti-S IgG) and employing a surrogate virus neutralization test (sVNT) for assessing the hACE2 receptor-binding inhibitory capacity of antibodies. The study revealed that humoral immunity post-vaccination is well established, with positive results for anti-S IgG in 92.9% of the total study cohort. Vaccinated and SARS-CoV-2-infected patients exhibited significantly higher anti-S IgG levels compared to vaccinated, non-infected patients (18,590 AU/mL vs. 2320 AU/mL, p < 0.001). Additionally, a significantly elevated receptor-binding inhibitory capacity was observed in the cPassTMTM sVNT (96.4% vs. 91.8%, p = 0.004). Furthermore, a substantial enhancement of anti-S IgG levels (p = 0.034) and receptor-binding inhibition capacity (p < 0.001) was observed with an increasing interval post-transplantation (up to 30 years), calculated by generalized linear model analysis. In summary, fully vaccinated liver transplant recipients exhibit robust humoral immunity against SARS-CoV-2, which significantly intensifies following infection and with increasing time after transplantation. These findings should be considered for booster vaccination schemes for liver transplant recipients.

Facile quantitative diagnostic testing for neutralizing antibodies against Chikungunya virus.

BACKGROUND: Viral neutralization (NT) assays can be used to determine the immune status of patients or assess the potency of candidate vaccines or therapeutic monoclonal antibodies (mAbs). Focus reduction neutralization test (FRNT) is a conventional neutralization test (cVNT) with superior specificity for measurement of neutralizing antibodies against a specific virus. Unfortunately, the application of FRNT to the chikungunya virus (CHIKV) involves a highly pathogenic bio-agent requiring biosafety level 3 (BSL3) facilities, which inevitably imposes high costs and limits accessibility. In this study, we evaluated a safe surrogate virus neutralization test (sVNT) that uses novel CHIKV replicon particles (VRPs) expressing eGFP and luciferase (Luc) to enable the rapid detection and quantification of neutralizing activity in clinical human serum samples. METHODS: This unmatched case-control validation study used serum samples from laboratory-confirmed cases of CHIKV (n = 19), dengue virus (DENV; n = 9), Japanese encephalitis virus (JEV; n = 5), and normal individuals (n = 20). We evaluated the effectiveness of sVNT, based on mosquito cell-derived CHIK VRPs (mos-CHIK VRPs), in detecting (eGFP) and quantifying (Luc) neutralizing activity, considering specificity, sensitivity, and reproducibility. We conducted correlation analysis between the proposed rapid method (20 h) versus FRNT assay (72 h). We also investigated the correlation between sVNT and FRNT in NT titrations in terms of Pearson's correlation coefficient (r) and sigmoidal curve fitting. RESULTS: In NT screening assays, sVNT-eGFP screening achieved sensitivity and specificity of 100%. In quantitative neutralization assays, we observed a Pearson's correlation coefficient of 0.83 for NT50 values between sVNT-Luc and FRNT. CONCLUSIONS: Facile VRP-based sVNT within 24 h proved highly reliable in the identification and quantification of neutralizing activity against CHIKV in clinical serum samples.

SARS-CoV-2 Omicron XBB.1 variant outbreak in a defined cohort: an epidemiological investigation incorporating longitudinal assessment of humoral response.

BACKGROUND: We describe an epidemiological investigation of a SARS-CoV-2-XBB.1 outbreak among healthcare workers (HCWs) returning from a 5-days educational tour abroad. METHODS: We prospectively followed participants for symptoms and sampled blood for neutralization assays of four SARS-CoV-2 variants (wild type, XBB, EG.5.1, and BA.2.86) at 1, 3, and 6 months after their return. When available, samples from the 3 months preceding the outbreak were also tested. We compared geometric mean titers (GMT) of neutralizing antibodies of infected versus uninfected HCWs and febrile versus afebrile infected HCWs. RESULTS: Nineteen (10%) of 181 HCWs were infected, all had mild COVID-19, 90% (17/19) had symptoms, and 16% (3/19) reported fever. Infected individuals tended to have lower pre-exposure XBB-neutralizing antibody titers (GMT of 32 versus 107 ID50, P = 0.248). Neutralization against XBB and newer subvariants peaked at 3 months and was higher among infected individuals (GMT 702 versus 156 [P < 0.001], 558 versus 163 [P = 0.001], and 558 vs. 182 [P = 0.002], ID50 for XBB, EG.5.1., and BA.2.86, respectively). By six months, these differences were no longer observed. Fever was positively associated with XBB neutralization (GMT 3474 versus 485, ID50 P = 0.005). CONCLUSIONS: Recently infected individuals are protected from reinfection with newer subvariants. However, protection is likely short lived.

Investigations on the Potential Role of Free-Ranging Wildlife as a Reservoir of SARS-CoV-2 in Switzerland.

Amid the SARS-CoV-2 pandemic, concerns surfaced regarding the spread of the virus to wildlife. Switzerland lacked data concerning the exposure of free-ranging animals to SARS-CoV-2 during this period. This study aimed to investigate the potential exposure of Swiss free-ranging wildlife to SARS-CoV-2. From 2020 to 2023, opportunistically collected samples from 712 shot or found dead wild mustelids (64 European stone and pine martens, 13 European badgers, 10 European polecats), canids (449 red foxes, 41 gray wolves, one golden jackal) and felids (56 Eurasian lynx, 18 European wildcats), as well as from 45 captured animals (39 Eurasian lynx, 6 European wildcats) were tested. A multi-step serological approach detecting antibodies to the spike protein receptor binding domain (RBD) and N-terminal S1 subunit followed by surrogate virus neutralization (sVNT) and pseudotype-based virus neutralization assays against different SARS-CoV-2 variants was performed. Additionally, viral RNA loads were quantified in lung tissues and in oronasal, oropharyngeal, and rectal swabs by reverse transcription polymerase chain reactions (RT-qPCRs). Serologically, SARS-CoV-2 exposure was confirmed in 14 free-ranging Swiss red foxes (prevalence 3.1%, 95% CI: 1.9-5.2%), two Eurasian lynx (2.2%, 95% CI: 0.6-7.7%), and one European wildcat (4.2%, 95% CI: 0.2-20.2%). Two positive foxes exhibited neutralization activity against the BA.2 and BA.1 Omicron variants. No active infection (viral RNA) was detected in any animal tested. This is the first report of SARS-CoV-2 antibodies in free-ranging red foxes, Eurasian lynx, and European wildcats worldwide. It confirms the spread of SARS-CoV-2 to free-ranging wildlife in Switzerland but does not provide evidence of reservoir formation. Our results underscore the susceptibility of wildlife populations to SARS-CoV-2 and the importance of understanding diseases in a One Health Concept.

The Anti-SARS-CoV-2 S-Protein IgG, Which Is Detected Using the Chemiluminescence Microparticle Immunoassay (CMIA) in Individuals Having Either a History of COVID-19 Vaccination and/or SARS-CoV-2 Infection, Showed a High-Titer Neutralizing Effect.

Neutralizing antibodies plays a primary role in protective immunity by preventing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from entering the cells. Therefore, characterization of antiviral immunity is important for protection against SARS-CoV-2. In this study, the neutralizing effect of the anti-SARS-CoV-2 S1 protein IgG, which was detected using the chemiluminescence microparticle immunoassay (CMIA)-based SARS-CoV-2 IgG II Quant (Abbott, Waukegan, IL, USA) test in SARS-CoV-2 infected and/or vaccinated individuals, was investigated with a surrogate virus neutralization test (sVNT). In total, 120 Seropositive individuals were included in this study. They were divided into two groups: Vaccinated (n = 60) and Vaccinated + Previously Infected (n = 60). A commercial sVNT, the ACE2-RBD Neutralization Test (Dia.Pro, Milan, Italy), was used to assess the neutralizing effect. The assay is performed in two steps: screening and titration. The screening showed positive results in all seropositive samples. Low titration in 1.7%, medium titration in 5%, and high titration in 93.3% of the Vaccinated group, and medium titration in 1.7% and high titration in 98.3% of the other group, as obtained from the ACE2-RBD titration test. A strong positive and significant correlation was found between the SARS-CoV-2 IgG II Quant test and the ACE2-RBD titration test at the 1/32 titration level for both groups (p < 0.001 for both). This study shows that the SARS-CoV-2 IgG detected using the CMIA method after SARS-CoV-2 infection and/or vaccination has a high neutralizing titration by using the sVNT. In line with these data, knowledge that seropositivity determined by CMIA also indicates a strong neutralizing effect contributes to countrywide planning for protecting the population.

Virus Neutralization Test for Detecting and Quantifying Serum-Neutralizing Antibodies to Epizootic Hemorrhagic Disease Virus (EHDV) (Serotypes 1, 2, and 4-8).

The virus neutralization test (VNT) is a functional immunoassay which detects the presence and quantity of neutralizing antibodies. It is a highly sensitive and specific test. As with most neutralization assays, the EHDV VNT does not react with all virus-targeting antibodies, but specifically with those antibodies that bind to VP2, the outermost capsid structural protein of the virus. The interaction between VP2 and neutralizing antibodies can block EHDV cell binding, neutralizing its infectivity. The detection and quantification of neutralizing antibodies are indicative of how protected an animal is against reinfection. The EHD VNT can therefore be a useful tool to monitor the efficacy of a vaccination campaign. VP2 is also the main determinant of EHDV serotype specificity, and so EHDV-neutralizing antibodies which target VP2 are also serotype-specific. Throughdetecting and quantifying neutralizing antibodies, the VNT can discriminate the EHDV serotype responsible for an infection and provides insights into the time of infection. It is considered the gold standard test for identifying and quantifying antibodies against EHDV serotypes present in test serum samples. The assay is performed in vitro and is based on inhibition of virus infectivity in the presence of neutralizing antibodies. A neutralizing antibody titer is determined through the presence or absence of cytopathic effect in a cell monolayer. The VNT is a relatively inexpensive assay using standard laboratory equipment; however, to perform the assay, cell cultures, significant time, intensive labor, and technical skill are required.

Characterization of monoclonal antibodies targeting SARS-CoV-2 spike glycoprotein: Reactivity against Delta and Omicron BA.1 variants.

The cross-species transmissibility of SARS-CoV-2 infection has necessitated development of specific reagents for detecting infection in various animal species. The spike glycoprotein of SARS-CoV-2, which is involved in viral entry, is a highly immunogenic protein. To develop assays targeting this protein, we generated eight monoclonal antibodies (mAbs) against the S1 and seven against the S1/S2 protein (ectodomain) of SARS CoV-2. Based on neutralization capability and reactivity profile observed in ELISA, the mAbs generated against the S1/S2 antigen exhibited a broader spectrum of epitope specificity than those produced against the S1 domain alone. The full-length ectodomain induced antibodies that could neutralize the two most important variants of the virus encountered during the pandemic, namely Delta and Omicron. The availability of these reagents could greatly enhance the development of precise diagnostics for detecting COVID-19 infections in various host species and contribute to the advancement of mAb-based therapeutics.

Development of an indirect ELISA for the immunoprotection evaluation of E2 antibodies against classical swine fever virus.

The Chinese government's reclassification of Classical Swine Fever (CSF) from a class Ⅰ to a class Ⅱ animal infectious disease, now also including CSF under the disease eradication program, reflects the significant progress made through extensive immunization with CSF vaccines. In light of this advancement, there is an imperative need for an expedient and accurate method to assess the levels of immunoprotection against classical swine fever virus (CSFV) in vaccinated pigs, a critical component in the campaign to eradicate the disease. This study develops an indirect enzyme-linked immunosorbent assay (iELISA) based on a highly glycosylated E2 protein stable expressed in CHO-K1 mammalian cells. Statistical analysis revealed strong positive correlations between the iELISA and VNT results (r = 0.9063, p < 0.0001) that were much greater than those between the IDEXX ELISA and VNT results (r = 0.8126, p < 0.0001). Taking the VNT data as the standard, the consistency of the iELISA (κ =0.880) was greater than that of the IDEXX ELISA (κ =0.699). In summary, the iELISA provides a more efficient and precise method for assessing CSFV immunity in pigs. Its reliable detection of immunoprotection levels against CSFV makes it an essential tool for optimizing CSF vaccination strategies. Consequently, its application can significantly support the ongoing efforts to eradicate CSF.

Dengue virus (DV) non-cross-reactive Omicron wave COVID-19 serums enhanced DV3 infectivity in vitro.

Introduction. In India, the SARS-CoV-2 Delta wave (2020-2021) faded away with the advent of the Omicron variants (2021-present). Dengue incidences were observed to be less in Southeast Asia during the active years of the pandemic (2020-2021). However, dengue virus type 3 (DV3) cases were increasingly reported in this region (including India) concurrent with the progression of the Omicron waves since 2022.Hypothesis. What could be the reason(s) behind this unusual DV3 surge after an overall dip in dengue incidences in many parts of Southeast Asia?Aim. We, therefore, investigated the current state of cross-reactivity of prevalent (Omicron era) SARS-CoV-2 serums with different DV serotypes and evaluated the impact of such serums on DV neutralization in cell culture.Methodology. Fifty-five COVID-19 serum samples (January-September 2022) and three pre-pandemic archived serum samples from apparently healthy individuals were tested for DV or SARS-CoV-2 IgM/IgG using the lateral flow immunoassays. DV1-4 virus neutralization tests (VNTs) were done with the SARS-CoV-2 antibody (Ab)-positive serums in Huh7 cells. DV3 envelope (env) gene was PCR amplified and sequenced for three archived DV isolates, one from 2017 and two from 2021.Results. SARS-CoV-2 Ab-positive samples constituted 74.5 % of the serums. Of these, 41.5 % were DV cross-reactive and 58.5 % were not. The DV cross-reactive serums neutralized all DV serotypes (DV1-4), as per previous results and this study. The DV non-cross-reactive serums (58.5 %) also cross-neutralized DV1, 2 and 4 but increased DV3 infectivity by means of antibody-dependent enhancement of infection as evident from significantly higher DV3 titres in VNT compared to control serums. The DV3 envelope was identical among the three isolates, including isolate 1 used in VNTs. Our results suggest that DV cross-reactivity of SARS-CoV-2 serums diminished with the shift from Delta to Omicron prevalence. Such COVID-19 serums (DV non-cross-reactive) might have played a major role in causing DV3 surge during the Omicron waves.Conclusion. Patients suspected of dengue or COVID-19 should be subjected to virus/antigen tests and serological tests for both the diseases for definitive diagnosis, prognosis and disease management.

Evidences support that dengue virus can impart broad-spectrum immunity against betacoronaviruses in dengue endemic regions.

COVID-19 tended to be less aggressive in dengue endemic regions. Conversely, dengue cases plummeted in dengue endemic zones during the active years of the pandemic (2020-2021). We and others have demonstrated serological cross-reactivity between these two viruses of different families. We further demonstrated that COVID-19 serum samples that were cross-reactive in dengue virus (DV) serological tests, "cross-neutralized" all DV serotypes in Huh7 cells. Here we showed by co-immunoprecipitation (Co-IP) and atomic force microscopy (AFM) imaging that severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 (SARS-CoV-2) spike (S) protein subunit S1 and S2 monoclonal antibodies can indeed, bind to DV particles. Likewise, DV envelope antibodies (DV E Abs) showed high docking frequency with other human pathogenic beta-CoVs and murine hepatitis virus-1 (MHV-1). SARS-CoV-2 Ab didn't show docking or Co-IP with MHV-1 supporting poor cross-protection among CoVs. DV E Abs showed binding to MHV-1 (AFM, Co-IP, and immunofluorescence) and prepandemic dengue patients' serum samples even "cross-neutralized" MHV-1 plaques in cell culture. Furthermore, dengue serum samples showed marked inhibition potential in a surrogate virus-based competitive enzyme-linked immunosorbent assay, used for determining neutralizing Abs against SARS-CoV-2 S protein receptor-binding domain in COVID-19 serum samples. We therefore, provide multiple evidence as to why CoVs are epidemiologically less prevalent in highly dengue endemic regions globally.

Antigenic Cartography of SARS-CoV-2.

Antigenic cartography is a tool for interpreting and visualizing antigenic differences between virus variants based on virus neutralization data. This approach has been successfully used in the selection of influenza vaccine seed strains. With the emergence of SARS-CoV-2 variants escaping vaccine-induced antibody response, adjusting COVID-19 vaccines has become essential. This review provides information on the antigenic differences between SARS-CoV-2 variants revealed by antigenic cartography and explores a potential of antigenic cartography-based methods (e.g., building antibody landscapes and neutralization breadth gain plots) for the quantitative assessment of the breadth of the antibody response. Understanding the antigenic differences of SARS-CoV-2 and the possibilities of the formed humoral immunity aids in the prompt modification of preventative vaccines against COVID-19.

Identifying Key Drivers of Efficient B Cell Responses: On the Role of T Help, Antigen-Organization, and Toll-like Receptor Stimulation for Generating a Neutralizing Anti-Dengue Virus Response.

T help (Th), stimulation of toll-like receptors (pathogen-associated molecular patterns, PAMPs), and antigen organization and repetitiveness (pathogen-associated structural patterns, PASPs) were shown numerous times to be important in driving B-cell and antibody responses. In this study, we dissected the individual contributions of these parameters using newly developed "Immune-tag" technology. As model antigens, we used eGFP and the third domain of the dengue virus 1 envelope protein (DV1 EDIII), the major target of virus-neutralizing antibodies. The respective proteins were expressed alone or genetically fused to the N-terminal fragment of the cucumber mosaic virus (CMV) capsid protein-nCMV, rendering the antigens oligomeric. In a step-by-step manner, RNA was attached as a PAMP, and/or a universal Th-cell epitope was genetically added for additional Th. Finally, a PASP was added to the constructs by displaying the antigens highly organized and repetitively on the surface of CMV-derived virus-like particles (CuMV VLPs). Sera from immunized mice demonstrated that each component contributed stepwise to the immunogenicity of both proteins. All components combined in the CuMV VLP platform induced by far the highest antibody responses. In addition, the DV1 EDIII induced high levels of DENV-1-neutralizing antibodies only if displayed on VLPs. Thus, combining multiple cues typically associated with viruses results in optimal antibody responses.

Serosurvey of Blood Donors to Assess West Nile Virus Exposure, South-Central Spain.

We analyzed West Nile Virus (WNV) exposure from 1,222 blood donors during 2017-2018 from an area of south-central Spain. Results revealed WNV seroprevalence of 0.08% (95% CI 0.004%-0.4%) in this population. Our findings underscore the need for continued surveillance and research to manage WNV infection in this region.

COVID-19 vaccination before or during pregnancy results in high, sustained maternal neutralizing activity to SARS-CoV-2 wild-type and Delta/Omicron variants of concern, particularly following a booster dose or infection.

OBJECTIVES: To investigate multi-dose and timings of COVID-19 vaccines in preventing antenatal infection. DESIGN: Prospective observational study investigating primary vaccinations, boosters, antenatal COVID-19 infections, neutralizing antibody (Nab) durability, and cross-reactivity to Delta and Omicron variants of concern (VOCs). RESULTS: Ninety-eight patients completed primary vaccination prepregnancy (29.6%) and antenatally (63.3%), 24.2% of whom had antenatal COVID-19, while 7.1% were unvaccinated (28.6% had antenatal COVID-19). None had severe COVID-19. Prepregnancy vaccination resulted in vaccination-to-infection delay of 23.3 weeks, which extended to 45.2 weeks with a booster, compared to 16.9 weeks following antenatal vaccination (P < 0.001). Infections occurred at 26.2 weeks gestation in women vaccinated prepregnancy compared to 36.2 weeks gestation in those vaccinated during pregnancy (P < 0.007). The risk of COVID-19 infection was higher without antenatal vaccination (hazard ratio [HR] 14.6, P = 0.05) and after prepregnancy vaccination without a booster (HR 10.4, P = 0.002). Antenatal vaccinations initially led to high Nab levels, with mild waning but subsequent rebound. Significant Nab enhancement occurred with a third-trimester booster. Maternal-neonatal Nab transfer was efficient (transfer ratio >1), and cross-reactivity to VOCs was observed. CONCLUSION: Completing vaccination during any trimester delays COVID-19 infection and maintains effective neutralizing activity throughout pregnancy, with robust cross-reactivity to VOCs and efficient maternal-neonatal transfer.

Persistence of passive immunity in calves receiving colostrum from cows vaccinated with a live attenuated lumpy skin disease vaccine and the performance of serological tests.

This study aimed to determine the persistent duration of maternal immunity against lumpy skin disease virus (LSDV) in dairy calves born from vaccinated cows using a virus neutralization test (VNT). The performance of the VNT and an in-house-ELISA test was also determined. Thirty-seven pregnant cows from 12 LSD-free dairy farms in Lamphun province, Thailand were immunized with a homologous Neethling strain-based attenuated vaccine and calved from December 2021 to April 2022. Blood samples from dam-calve pairs were collected within the first week after calving. Subsequently, blood samples were taken from the calves at monthly intervals over a period of 4 months and tested for the humoral immune response using a VNT. The calf sera were also tested with an in-house ELISA test to estimate the accuracy of both tests using a Bayesian approach. For the results, antibodies against LSDV can persist in cows for 4-9 months post-vaccination. Moreover, neutralizing antibodies and LSDV-specific antibodies against LSDV were detected in the majority of calves (75.68%) during the first week after colostrum intake. However, the percentage of seropositive calves declined to zero by day 120, with seropositivity dropping below 50% after day 60. Only a small number of seropositive calves (approximately 13.51%) were observed on day 90. These findings indicated that passive immunity against LSDV can last up to 3 months. The median of posterior estimates for sensitivity (Se) and specificity (Sp) of the VNT were 87.3% [95% posterior probability interval (PPI) = 81.1-92.2%] and 94.5% (95% PPI = 87.7-98.3%), respectively. The estimated Se and Sp for the ELISA test were 83.1% (95% PPI = 73.6-92.6%) and 94.7% (95% PPI = 88.4-98.5%), respectively. In conclusion, this study illustrates the transfer and persistence of maternal passive immunity against LSDV to calves under field conditions. This highlights a potential three-month vaccination gap in calves born from vaccinated cows, while an in-house ELISA test can be used as an ancillary test for LSDV immune response detection. However, further research is required to assess the vaccination protocols for calves as young as 2 months old to precisely determine the duration of maternal immunity.

Immunoadsorption as a method of antibody donation during the COVID-19 pandemic.

BACKGROUND AND OBJECTIVES: Initial therapeutic efforts to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) included the use of plasma from convalescent donors containing anti-SARS-CoV-2 antibodies. High-neutralizing antibody titres are required for therapeutic efficacy. This study aims to show that immunoadsorption followed by tangential flow filtration can be used to obtain antibody concentrates with high-neutralizing capacities. MATERIALS AND METHODS: Eligible donors (n = 10, five males and three females) underwent immunoadsorption using adsorber columns specific for human antibodies. Glycine-washed out eluates of 1.5 L volume were further concentrated by tangential flow filtration using 30 kDa ultrafiltration membranes. The same membranes were applied for diafiltrations to exchange residual glycine for 0.9% normal saline. RESULTS: Antibody concentrates were obtained within 8 h from the start of donation and had 4.58 ± 1.95, 3.28 ± 1.28 and 2.02 ± 0.92 times higher total IgG, IgA and IgM concentrations, 3.29 ± 1.62 and 3.74 ± 0.6 times higher SARS-CoV-2 N and S antibody concentrations and 3.85 ± 1.71 times higher SARS-CoV-2 S-specific IgG concentrations compared to the donors' peripheral blood. The specific SARS-CoV-2 virus neutralization capacities increased in all but one concentrate. All antibody concentrates (50-70 mL final volume) passed microbiological tests, were free of hazardous glycine levels and could be stored at -80°C and 4°C for 1 year with 20 ± 3% antibody loss. CONCLUSION: Immunoadsorption followed by tangential flow filtration is a feasible procedure to collect IgG, IgA and IgM as well as SARS-CoV-2 N- and S-specific antibody concentrates of low volume, free of albumin and coagulation factors. Whether these concentrates can be used as passive immunisation in infected patients remains to be elucidated.

Seroprevalence of Bovine Viral Diarrhea Virus in Wild Pigs (Sus scrofa) in 17 States in the USA.

Wild pigs (Sus scrofa) are among the most detrimental invasive species in the USA. They are damaging to crops and agriculture, pose a public health risk as reservoirs of zoonotic pathogens, and may also spread disease to livestock. One pathogen identified in wild pigs is bovine viral diarrhea virus (BVDV), a virus that causes an economically important disease of cattle (Bos taurus and Bos indicus). We sought to determine the BVDV seroprevalence in wild pigs in 17 states across the US and to determine whether age category, sex, or location were associated with a positive antibody titer. Serum samples from 945 wild pigs were collected from 17 US states. Virus neutralization assays were performed to determine antibody titers against BVDV-1b and BVDV-2a. Total BVDV seroprevalence for the study area was 5.8% (95% confidence interval [CI], 4.11-8.89). Seroprevalence across all evaluated states was determined to be 4.4% (95% CI, 2.48-6.82) for BVDV-1b and 3.6% (95% CI, 1.54-5.60) for BVDV-2a. The seroprevalence for individual states varied from 0% to 16.7%. There was no statistical difference in median antibody titer for BVDV-1b or BVDV-2a by sex or age category. State seroprevalences for both BVDV-1b and BVDV-2a were associated with wild pig population estimates for those states.

Serological Profile for Major Respiratory Viruses in Unvaccinated Cows from High-Yielding Dairy Herds.

This study aims to determine the serological profile of high-yielding dairy cows for four main viruses (bovine alphaherpesvirus 1 (BoAHV1), bovine viral diarrhea virus (BVDV), bovine parainfluenza virus 3 (BPIV3), and bovine respiratory syncytial virus (BRSV)) related to bovine respiratory disease (BRD) in cattle herds worldwide. In this survey, 497 blood serum samples were collected from non-vaccinated dairy cows without clinical respiratory signs in 39 herds in the central-eastern mesoregion of Paraná State, South Brazil. The presence of neutralizing antibodies was determined by virus neutralization (VN) tests. VN antibodies against BoAHV1, BVDV, BPIV3, and BRSV were detected in 355 (71.4%), 280 (56.3%), 481 (96.8%), and 315 (63.4%) serum samples, respectively. The frequencies of seropositive herds for BoAHV1, BVDV, BPIV3, and BRSV were 79.5 (n = 31), 82.0 (n = 32), 100 (n = 39), and 84.6% (n = 33), respectively. The frequencies of seropositive cows varied according to the type of herd management and the number of cows in the herd. The detection of VN antibodies in unvaccinated dairy cattle herds demonstrated the endemic circulation of the four viruses in the herds evaluated. For BRD prevention, it is recommended to implement a vaccination program for cows that provides passive immunity in calves and active immunity in cows.

Evaluation of Swine Protection with Three Commercial Foot-and-Mouth Disease Vaccines against Heterologous Challenge with Type A ASIA/G-VII Lineage Viruses.

Outbreaks caused by foot-and-mouth disease (FMD) A/ASIA/G-VII lineage viruses have often occurred in Middle Eastern and Southeast Asian countries since 2015. Because A/ASIA/G-VII lineage viruses are reported to have distinct antigenic relatedness with available commercial FMD vaccine strains, it is necessary to investigate whether inoculation with vaccines used in Korea could confer cross-protection against A/ASIA/G-VII lineage viruses. In the present study, we conducted two vaccination challenge trials to evaluate the efficacy of three commercial FMD vaccines (O/Manisa + O/3039 + A/Iraq, O/Campos + A/Cruzeiro + A/2001, and O/Primorsky + A/Zabaikalsky) against heterologous challenge with ASIA/G-VII lineage viruses (A/TUR/13/2017 or A/BHU/3/2017 strains) in pigs. In each trial, clinical signs, viremia, and salivary shedding of virus were measured for 7 days after challenge. In summary, the O/Campos + A/Cruzeiro + A/2001 vaccine provided full protection against two A/ASIA/G-VII lineage viruses in vaccinated pigs, where significant protection was observed. Although unprotected animals were observed in groups vaccinated with O/Manisa + O/3039 + A/Iraq or O/Primorsky + A/Zabaikalsky vaccines, the clinical scores and viral RNA levels in the sera and oral swabs of vaccinated animals were significantly lower than those of unvaccinated controls.