Development of monoclonal antibody-based blocking ELISA for detecting SARS-CoV-2 exposure in animals (preprint)

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a significant threat to public health. Besides humans, SARS-CoV-2 can infect several animal species. Highly sensitive and specific diagnostic reagents and assays are urgently needed for rapid detection and implementation of strategies for prevention and control of the infection in animals. In this study, we initially developed a panel of monoclonal antibodies (mAbs) against SARS-CoV-2 nucleocapsid (N) protein. To detect SARS-CoV-2 antibodies in a broad spectrum of animal species, a mAb-based bELISA was developed. Test validation using a set of animal serum samples with known infection status obtained an optimal percentage of inhibition (PI) cut-off value of 17.6% with diagnostic sensitivity of 97.8% and diagnostic specificity of 98.9%. The assay demonstrates high repeatability as determined by a low coefficient of variation (7.23%, 6.95%, and 5.15%) between-runs, within-run, and within-plate, respectively. Testing of samples collected over time from experimentally infected cats showed that the bELISA was able to detect seroconversion as early as 7 days post-infection. Subsequently, the bELISA was applied for testing pet animals with COVID-19-like symptoms and specific antibody responses were detected in two dogs. The panel of mAbs generated in this study provides a valuable tool for SARS-CoV-2 diagnostics and research. The mAb-based bELISA provides a serological test in aid of COVID-19 surveillance in animals.

Pandemic Hits: Evaluation of an Antimicrobial Stewardship Program Website for Hospital Communication During the COVID-19 Pandemic

Background. Antibiotic Stewardship Programs (ASPs) assist front-line clinicians in synthesizing emerging data and establishing best practices. Our ASP team directly maintained and edited an internal web application, Duke CustomID , to disseminate updated guideline, policy, and drug information during COVID-19. We aimed to describe website engagement and maintenance during the dynamic pandemic period. Methods. We performed a descriptive, time-series analysis using Google Analytics software to measure engagement with Duke CustomID during a 1-year prepandemic period through the Omicron surge: January 2019 to March 2022. We measured total page views (or 'hits'), COVID-specific page hits, and days requiring COVID-specific page edits by week. Given fluctuations in hospitalization rates, we defined the primary outcome as the rate of hits divided by total hospitalizations. Weekly data were assessed graphically with positive COVID tests and COVID hospitalizations. We used negative binomial regression to quantify the association between COVID hospitalizations and hit rates and to trend engagement over time, adjusted for seasonality. We stratified data by COVID page and calculated a hit/edit ratio. Results. Engagement with CustomID increased during the pandemic period, especially during surges (Figure). Hits in the pre-pandemic period were median 1707 (range 1165-2354) per week, and hit rates median 1.95 per hospitalization (range 1.40-2.86). Peaks were observed in March 2020 (hit rate 4.59) and January 2022 (hit rate 3.87). On average, for every 100 COVID hospitalizations, the hit rate increased by 0.08 (0.004-0.16, p=0.04). Engagement slowly increased over the study period (relative rate week 1 versus 170: 1.15, 95% confidence interval 1.02-1.28, p=0.02). COVID page edits per week had a median of 2 (range 0-12). Adult Inpatient Guidelines and COVID Monoclonal Antibody pages had highest use (Table). Duke CustomID Hits and Maintenance Efforts over the Pandemic Top: COVID-specific CustomID hits per week (Green), Positive COVID tests per week (Blue) over time Middle: Total custom ID page hits relative to total hospitalizations per week (teal), COVID hospitalizations (Red) Bottom: Number of edits to COVID-specific CustomID pages per week, stratified by management pages and drug pages Several dates of significance are highlighted including the Emergency Use Authorizations (EUA) for remdesivir, the COVID Vaccines, and Paxlovid Duke CustomID COVID-19 Page Hits and Edits COVID specific pages on Duke CustomID with total hits, edits, and ratio over the pandemic Conclusion. Our ASP's website was a highly utilized, practical tool for disseminating practice-changing information during the pandemic. Use increased over time and especially during surges. An electronic reference customized for local practice and rapidly updated by ASPs offers critical support for front-line clinicians.

Adapting In-Person National Emergency Medical Teams (EMT) Introductory Training to a Virtual, Storytelling (Talanoa) Format for Pacific Island Countries and Areas (PICs)

Background/Introduction:Many Pacific governments have committed to establishing deployable, self-sufficient national EMTs following recent tropical cyclones, measles outbreaks, and the COVID-19 pandemic. However, for much of the COVD-19 pandemic, PICs have closed international borders limiting in-person team member training.Objectives:To develop a remote, interactive EMT training series to engage current and prospective EMT team members in the PICs during the COVID-19 pandemic.Method/Description:From July through September 2021, WHO hosted a weekly webinar series to introduce the concepts of the EMT Initiative to current and prospective EMT team members in the PICs. The sessions utilized Pacific deployment experience using faculty from EMTs in Australia, Fiji, New Zealand, Papua New Guinea, Solomon Islands, Tonga, and Vanuatu.Results/Outcomes:Attendees from over 23 countries from across the Pacific and other areas of the world participated in the 11 sessions, with a total of over 300 individual participants. The average number of participants per sessions was 85. Feedback was sought after every session. The most significant adaptation of the sessions from the feedback was incorporating the Pacific tradition of talanoa, or storytelling, into the sessions.Conclusion:Adapting the session plans to incorporate the talanoa style of communication in the Pacific created an environment of learning from colleagues throughout the Pacific and increased participant engagement in the virtual setting. The webinar series provided knowledge of EMT basics and increased engagement and excitement in the establishment and continued growth of EMTs in the Pacific.

Babies born in the 1st 2020 lockdown: Early data from the CORAL study

Background: The CORAL study is a cross-sectional study of the impact of the Coronavirus pandemic on allergic and autoimmune dysregulation of infants born in March, April and May 2020, during Ireland's 1 st COVID-19 pandemic Lockdown. Method: Invitations were sent to families of 3065 term, singleton babies. Exclusion criteria were ante-natal PCR-proven SARSCoV-2 in a parent or co-dwelling person, IV antibiotics in neonatal period, multiple births and major congenital anomalies. At 6 months babies were invited to attend CHI Connolly for point-of-care SARSCoV-2 antibody testing. Results: Of the 3065 letters sent 353 babies were enrolled.53.7% of enrolled infants were male, 78.4% were white-Irish, average birth weight was 3.506kg. 45% were first-born and 95.5% of mothers were educated at 3 rd level or higher. Babies' average number of close contacts other than household members was 2.3 during lockdown and 5.6 afterwards. 42.5% were reported to be currently breast-fed at enrolment. By 6 months, 97% of infants had solid foods introduced but only 24.5% had tried egg and 9.6% had tried peanut. Complete primary immunisation uptake at 6 months was 99%. Lastly, 3 babies out of 200 (1.3%) tested showed presence of IgM & IgG SARSCoV-2 antibodies;2 were PCR negative, the other PCR positive. Conclusion: Initial breastfeeding and immunisation uptake to 6 months are reassuringly high in this self-selected, highly-educated cohort. The rare positive antibody tests suggest recent or current infection, so newborn babies appear to have been protected from SARSCoV-2 exposure during the 1 st COVID Pandemic lockdown.

An accessible method for screening aerosol filtration identifies poor-performing commercial masks and respirators.

BACKGROUND: The COVID-19 pandemic has presented an acute shortage of regulation-tested masks. Many of the alternatives available to hospitals have not been certified, leaving uncertainty about their ability to properly protect healthcare workers from SARS-CoV-2 transmission. OBJECTIVE: For situations where regulatory methods are not accessible, we present experimental methods to evaluate mask filtration and breathability quickly via cost-effective approaches (e.g., ~$2000 USD) that could be replicated in communities of need without extensive infrastructure. We demonstrate the need for screening by evaluating an existing diverse inventory of masks/respirators from a local hospital. METHODS: Two experimental approaches are presented to examine both aerosol filtration and flow impedance (i.e., breathability). For one of the approaches ("quick assessment"), screening for appropriate filtration could be performed under 10 min per mask, on average. Mask fit tests were conducted in tandem but are not the focus of this study. RESULTS: Tests conducted of 47 nonregulation masks reveal variable performance. A number of commercially available masks in hospital inventories perform similarly to N95 masks for aerosol filtration of 0.2 µm and above, but there is a range of masks with relatively lower filtration efficiencies (e.g., <90%) and a subset with poorer filtration (e.g., <70%). All masks functioned acceptably for breathability, and impedance was not correlated with filtration efficiency. SIGNIFICANCE: With simplified tests, organizations with mask/respirator shortages and uncertain inventories can make informed decisions about use and procurement.

Effects of medium chain fatty acids as a mitigation or prevention strategy against porcine epidemic diarrhea virus in swine feed.

Feed has been shown to be a vector for viral transmission. Four experiments were conducted to: 1) determine if medium chain fatty acids (MCFA) are effective mitigants when applied to feed both pre- and post-porcine epidemic diarrhea virus (PEDV) inoculation measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), 2) evaluate varying levels and combinations of MCFA measured by qRT-PCR, and 3) evaluate selected treatments in bioassay to determine infectivity. In exp. 1, treatments were arranged in a 2 × 2 + 1 factorial with main effects of treatment (0.3% commercial formaldehyde [CF] product, Sal CURB [Kemin Industries, Inc.; Des Moines, IA], or 1% MCFA blend (Blend) of 1:1:1 C6:C8:C10 [PMI, Arden Hills, MN]) and timing of application (pre- or post-inoculation with PEDV) plus a positive control (PC; feed inoculated with PEDV and no treatment). All combinations of treatment and timing decreased detectable PEDV compared with the PC (P < 0.05). Pre-inoculation treatment elicited decreased magnitude of PEDV detection (cycle threshold value) compared with post-inoculation (P = 0.009). Magnitude of PEDV detection was decreased for CF compared with Blend (P < 0.0001). In exp. 2, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 5) 0.125% to 0.33% C6:0, 6 to 8) 0.125% to 0.33% C8:0, 9 to 11) 0.125% to 0.33% C10:0, and 12 to 15) 0.125% to 0.66% C5:0. Treating feed with 0.33% C8:0 resulted in decreased (P < 0.05) PEDV detection compared with all other treatments. Increasing concentration of each individual MCFA decreased PEDV detectability (P < 0.042). In exp. 3, pre-inoculation treatments consisted of: 1) PC, 2) 0.3% CF, 3 to 7) 0.25% to 1% Blend, 8 to 10) 0.125% to 0.33% C6:0 + C8:0, 11 to 13) 0.125% to 0.33% C6:0 + C10:0, and 14 to 16) 0.125% to 0.33% C8:0 + C10:0. Treating feed with CF, 0.5% Blend, 0.75% Blend, 1% Blend, all levels of C6:0+C8:0, 0.25% C6:0 + 0.25% C10:0, 0.33% C6:0 + 0.33% C10:0, 0.25% C8:0 + 0.25% C10:0, or 0.33% C8:0 + 0.33% C10:0 elicited decreased detection of PEDV compared with PC (P < 0.05). Increasing concentration of each MCFA combination decreased PEDV detectability (linear, P < 0.012). In exp. 4, feed was treated pre-inoculation with: 1) no treatment (PC), 2) 0.3% CF, 3) 0.5% Blend, or 4) 0.3% C8:0 and analyzed via qRT-PCR and bioassay. Adding 0.5% Blend or 0.3% C8:0 resulted in decreased PEDV compared with PC and only PC resulted in a positive bioassay. Therefore, MCFA can decrease detection of PEDV in feed. Further, inclusion of lower levels of MCFA than previously evaluated are effective against PEDV.