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SARS-CoV-2 variants may threaten the effectiveness of vaccines and antivirals to mitigate serious COVID-19 disease. This is of most concern in clinically vulnerable groups such as older adults. We analysed 72 sera samples from 37 individuals, aged 70–89 years, vaccinated with two doses of BNT162b2 (Pfizer–BioNTech) 3 weeks apart, for neutralizing antibody responses to wildtype SARS-CoV-2. Between 3 and 20 weeks after the second vaccine dose, neutralizing antibody titres fell 4.9-fold to a median titre of 21.3 (neutralization dose 80%), with 21.6% of individuals having no detectable neutralizing antibodies at the later time point. Next, we examined neutralization of 21 distinct SARS-CoV-2 variant spike proteins with these sera, and confirmed substantial antigenic escape, especially for the Omicron (B.1.1.529, BA.1/BA.2), Beta (B.1.351), Delta (B.1.617.2), Theta (P.3), C.1.2 and B.1.638 spike variants. By combining pseudotype neutralization with specific receptor-binding domain (RBD) enzyme-linked immunosorbent assays, we showed that changes to position 484 in the spike RBD were mainly responsible for SARS-CoV-2 neutralizing antibody escape. Nineteen sera from the same individuals boosted with a third dose of BNT162b2 contained higher neutralizing antibody titres, providing cross-protection against Omicron BA.1 and BA.2. Despite SARS-CoV-2 immunity waning over time in older adults, booster vaccines can elicit broad neutralizing antibodies against a large number of SARS-CoV-2 variants in this clinically vulnerable cohort.

SARS-CoV-2 variants threaten the effectiveness of tools we have developed to mitigate against serious COVID-19. This is especially true in clinically vulnerable sections of society including the elderly. Using sera from BNT162b2 (Pfizer–BioNTech) vaccinated individuals aged between 70 and 89 (vaccinated with two doses 3-weeks apart) we examined the neutralising antibody (nAb) response to wildtype SARS-CoV-2. Between 3 and 20-weeks post 2nd dose, nAb titres dropped 4.9-fold to a median titre of 21.3 (ND80) with 21.6% of individuals having no detectable nAbs at the later time point. Experiments examining the neutralisation of twenty-one different SARS-CoV-2 variant spike proteins confirmed a significant potential for antigenic escape, especially for the Omicron (BA.1), Beta (B.1.351), Delta (B.1.617.2), Theta (P.3), C.1.2 and B.1.638 variants. Interestingly, however, the recently-emerged sub-lineage AY.4.2 was more efficiently neutralised than parental Delta pseudotypes. Combining pseudotype neutralisation with specific receptor binding domain (RBD) ELISAs we confirmed that changes to position 484 in the spike RBD were predominantly responsible for SARS-CoV-2 nAb escape, although the effect of spike mutations is both combinatorial and additive. Lastly, using sera from the same individuals boosted with a 3rd dose of BNT162b2 we showed that high overall levels of neutralising antibody titre can provide significant levels of cross-protection against Omicron. These data provide evidence that SARS-CoV-2 neutralising antibodies wane over time and that antigenically variable SARS-CoV-2 variants are circulating, highlighting the importance of ongoing surveillance and booster programmes. Furthermore, they provide important data to inform risk assessment of new SARS-CoV-2 variants, such as Omicron, as they emerge.

Seroepidemiological studies to monitor antibody kinetics are important for assessing the extent and spread of SARS-CoV-2 in a population. Non-invasive sampling methods are advantageous to reduce the need for venepuncture, which may be a barrier to investigations particularly in paediatric populations. Oral Fluids are obtained by gingiva-crevicular sampling from children and adults and are very well accepted. ELISA based on these samples have acceptable sensitivity and specificity compared to conventional serum-based antibody ELISAs and are suitable for population-based surveillance.We describe the development and evaluation of SARS-COV-2 IgG ELISAs using SARS-CoV-2 viral nucleoprotein (NP) and spike (S) proteins in IgG isotype capture format and an indirect receptor-binding-domain (RBD) IgG ELISA, intended for use in children. All three assays were assessed using a panel of 1999 paired serum and oral fluids from children and adults participating in national primary school SARS-CoV-2 surveillance studies during and after the first and second pandemic wave in the UK. The anti NP IgG capture assay was the best candidate, with an overall sensitivity of 75% (95% CI: 71–79%) specificity of 99% (95% CI: 78–99%) when compared with paired serum antibodies measured using a commercial assay SARS-CoV-2 nucleoprotein IgG assay (Abbott, Chicago, IL, USA). Higher sensitivity was observed in children (80%, 95% CI: 71–88%) compared to adults (67%, CI: 60%-74%). Oral fluid assays using spike protein and RBD antigens were also 99% specific and achieved reasonable but lower sensitivity in the target population (78%, 95% CI (68%-86%) and 53%, 95% CI (43%-64%), respectively).Conclusion statementOral Fluid assays based on the detection of SARS-CoV-2 antibodies are a suitable tool for population based seroepidemiology studies in children.

Introduction In patients with pancreaticobiliary lesions anticipating surgical resection, digital pancreaticocholangioscopy can be used to identify the extent of disease. This presurgical"mapping" could change the surgical plan and optimize patient care. Materials and methods Patients with pancreaticobiliary lesions anticipating surgery who underwent endoscopic retrograde cholangiopancreatography with digital pancreaticocholangioscopy from 9 international centers were included. Primary outcome was whether pancreaticocholangioscopy altered the surgical plan. Secondary outcome was correlation between surgical and endoscopic histology and adverse events. Results A total of 118 patients were included (64% male, mean age 69 y): cholangioscopy in 105 patients (89%), pancreatoscopy in 13 patients (11%). Pancreaticocholangioscopy changed the surgical plan in 39 (34%) of patients: 8 of 13 in the pancreatic duct, 32 of 105 in the bile duct. In the bile duct, 6 patients (5%) had less extensive surgery, 26 patients (25%) avoided surgery. In the pancreatic duct, 4 patients (31%) had more extensive surgery and 4 patients (31%) had less extensive surgery. Four patients with downstaged surgery had positive margins on surgical resection; 1 required additional surgical intervention. Overall correlation between endoscopy and surgical histology was 88%. Adverse events included post endoscopic retrograde cholangiopancreatography pancreatitis in 3 patients (2.5%). Conclusion Digital pancreaticocholangioscopy can be effectively used as a mapping tool to delineate the degree of involvement of biliary lesions before surgical resection, in some cases altering the surgical plan. Prospective studies are needed, especially when downstaging surgery.

The hemagglutination inhibition (HAI) assay is an established technique for assessing influenza immunity, through measurement of antihemagglutinin antibodies. Improved reproducibility of this assay is required to provide meaningful data across different testing laboratories. This study assessed the impact of harmonizing the HAI assay protocol/reagents and using standards on interlaboratory variability. Human pre- and postvaccination sera from individuals (n = 30) vaccinated against influenza were tested across six laboratories. We used a design of experiment (DOE) method to evaluate the impact of assay parameters on interlaboratory HAI assay variability. Statistical and mathematical approaches were used for data analysis. We developed a consensus protocol and assessed its performance against in-house HAI testing. We additionally tested the performance of several potential biological standards. In-house testing with four reassortant viruses showed considerable interlaboratory variation (geometric coefficient of variation [GCV] range of 50% to 117%). The age, concentration of turkey red blood cells, incubation duration, and temperature were key assay parameters affecting variability. Use of a consensus protocol with common reagents, including viruses, significantly reduced GCV between laboratories to 22% to 54%. Pooled postvaccination human sera from different vaccination campaigns were effective as biological standards. Our results demonstrate that the harmonization of protocols and critical reagents is effective in reducing interlaboratory variability in HAI assay results and that pools of postvaccination human sera have potential as biological standards that can be used over multiple vaccination campaigns. Moreover, the use of standards together with in-house protocols is as potent as the use of common protocols and reagents in reducing interlaboratory variability. IMPORTANCE The hemagglutination inhibition (HAI) assay is the most commonly used serology assay to detect antibodies from influenza vaccination or influenza virus infection. This assay has been used for decades but requires improved standardization of procedures to provide meaningful data. We designed a large study to assess selected parameters for their contribution to assay variability and developed a standard protocol to promote consistent HAI testing methods across laboratories. The use of this protocol and common reagents resulted in lower levels of variability in results between participating laboratories than achieved using in-house HAI testing. Human sera sourced from vaccination campaigns over several years, and thus including antibody to different influenza vaccine strains, served as effective assay standards. Based on our findings, we recommend the use of a common protocol and/or human serum standards, if available, for testing human sera for the presence of antibodies against seasonal influenza using turkey red blood cells.

Background The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the practice of endoscopy, but characteristics of COVID patients undergoing endoscopy have not been adequately described. Aims To compare findings, clinical outcomes, and patient characteristics of endoscopies performed during the pandemic in patients with and without COVID-19. Methods This was a retrospective multicenter study of adult endoscopies at six academic hospitals in New York between March 16 and April 30, 2020. Patient and procedure characteristics including age, sex, indication, findings, interventions, and outcomes were compared in patients testing positive, negative, or untested for COVID-19. Results Six hundred and five endoscopies were performed on 545 patients during the study period. There were 84 (13.9%), 255 (42.2%), and 266 (44.0%) procedures on COVID-positive, negative, and untested patients, respectively. COVID patients were more likely to undergo endoscopy for gastrointestinal bleeding or gastrostomy tube placement, and COVID patients with gastrointestinal bleeding more often required hemostatic interventions on multivariable logistic regression. COVID patients had increased length of stay, intensive care unit admission, and intubation rate. Twenty-seven of 521 patients (5.2%) with no or negative COVID testing prior to endoscopy later tested positive, a median of 13.5 days post-procedure. Conclusions Endoscopies in COVID patients were more likely to require interventions, due either to more severe illness or a higher threshold to perform endoscopy. A significant number of patients endoscoped without testing were subsequently found to be COVID-positive. Gastroenterologists in areas affected by the pandemic must adapt to changing patterns of endoscopy practice and ensure pre-endoscopy COVID testing. Electronic supplementary material The online version of this article (10.1007/s10620-020-06593-9) contains supplementary material, which is available to authorized users.

The COVID-19 pandemic seemingly is peaking now in New York City and has triggered significant changes to the standard management of gastrointestinal diseases. Priorities such as minimizing viral transmission, preserving personal protective equipment, and freeing hospital beds have driven unconventional approaches to managing gastroenterology (GI) patients. Conversion of endoscopy units to COVID units and redeployment of GI fellows and faculty has profoundly changed the profile of most GI services. Meanwhile, consult and procedural volumes have been reduced drastically. In this review, we share our collective experiences regarding how we have changed our practice of medicine in response to the COVID surge. Although we review our management of specific consults and conditions, the overarching theme focuses primarily on noninvasive measures and maximizing medical therapies. Endoscopic procedures have been reserved for those timely interventions that are most likely to be therapeutic. The role of multidisciplinary discussion, although always important, now has become critical. The support of our faculty and trainees remains essential. Local leadership can encourage well-being by frequent team check-ins and by fostering trainee development through remote learning. Advancing a clear vision and a transparent process for how to organize and triage care in the recovery phase will allow for a smooth transition to our new normal.

Introduction Intraabdominal fluid collections that previously required surgical intervention can now be drained with less invasive techniques. The use of lumen-apposing metal stents (LAMS) to treat pancreatic pseudocysts and perirectal abscesses has been shown to be a safe and effective technique in adults. We aim to evaluate the indications, outcomes, and complications of the use of LAMS in pediatric patients at our institution. Methods A retrospective chart review was performed to study patients up to 18 years of age at the Children's Hospital at Montefiore who underwent drainage of intraabdominal fluid collections with the use of LAMS. The main outcome measures were technical and clinical success and associated adverse events with LAMS placement. Results Seven patients (2 girls) ranging from 9 to 18 years were identified. Four patients had perirectal abscess postperforated appendicitis and 3 patients had pancreatic pseudocysts. All of the patients had complete resolution of the collections, with no recurrence, and our technical and clinical success rate was 100%. Only 1 patient had mild bleeding after placement that spontaneously resolved. Discussion Our study demonstrates the efficacy and safety of the use of LAMS for the drainage of intraabdominal fluid collections in pediatric patients, although the number of patients included is limited.

Background and Aims Postsurgical fluid collections (PSFCs) are traditionally drained either percutaneously or surgically. Endoscopic drainage offers several advantages compared with either percutaneous or surgical approaches, including avoiding repeat surgery or the need to have a percutaneous drain in place for weeks. There are very little data regarding the use of lumen-apposing metal stents (LAMSs) in the drainage of PSFCs. We aim to study the technical and clinical success and adverse events (AEs) of using LAMSs in the drainage of PSFCs. Methods Collaborators from 8 centers retrospectively reviewed their endoscopic databases to find procedures using LAMSs for drainage of PSFCs. Technical success (successful placement of LAMSs into the fluid collection), clinical success (complete resolution of the fluid collection on repeat imaging or endoscopy), and intraprocedure and postprocedure AEs were measured. Results Forty-seven patients were identified with PSFCs after various surgeries. Thirteen patients had failed previous percutaneous or surgical drainage attempts. Fluid collections averaged 78.6 mm (range, 47-150 mm) in size. The most common site of stent placement was transgastric, followed by rectum and duodenum. Technical success rate was 93.6% and clinical success rate 89.3%. The intraprocedural AE rate was 4.25% and postprocedural AE rate 6.4%. There was 1 death unrelated to the procedure. Conclusions The use of LAMSs to drain PSFCs has a high technical and clinical success rate with low AEs. For collections that are favorably located adjacent to the stomach, duodenum, or rectum, LAMS placement is a viable alternative to repeat surgery or percutaneous drainage.

A 45-year-old man presented with abdominal pain, fever with chills, nonproductive cough, mild pleurisy, and anorexia. Computed tomography scan showed a heterogeneously enhancing mass in the left hepatic lobe with leukocytosis and elevated C-reactive protein. Interval growth of the lesion was noted on magnetic resonance imaging obtained several days after admission. Given the clinical suspicion for pyogenic liver abscess and favorable location in the left hepatic lobe, endoscopic ultrasound-guided drainage was pursued. The patient underwent endoscopic ultrasound-guided hepaticogastrostomy with a lumen-apposing metal stent. His symptoms gradually abated after procedure. Radiographic resolution of the abscess was noted 1 week after stent placement, and the stent was subsequently removed. He had no clinical or radiographic evidence of recurrence at 1-month follow-up.

INTRODUCTION: Recent literature concerning the COVID-19 outbreak reported GI endoscopy as a potential source of infection for healthcare workers However, not much is known about the risk for patients during endoscopy The goal of this study is to assess the risk of COVID-19 transmission for patients undergoing endoscopic procedures during the pandemic METHODS: We performed a retrospective chart review on all patients >18 years old who underwent an endoscopic procedure including EGD, colonoscopy, ERCP and EUS between March 2nd and May 27th at a single center in the Bronx, NY We identified patients who had a COVID-19 test performed prior to the procedure Patients who tested negative were contacted by phone A questionnaire was used to identify patients who had developed fever, respiratory symptoms, or gastrointestinal symptoms In addition, we also identified patients who were diagnosed as COVID-19 positive within 2 weeks after the procedures RESULTS: Of the 412 patients that underwent endoscopic procedures only 191 (46%) had a COVID-19 test done prior;41 (21 5%) tested positive, 150 (78 5%) tested negative All 150 patients who had an endoscopic procedure performed, (70 EGDs, 38 colonoscopies, 34 ERCPs, and 21 EUS ) (Figure 1) received a 2-week follow-up phone call;the response rate was 112 (75%) None of these 112 patients developed symptoms, (fever, cough, dyspnea, sore throat, diarrhea, vomit, dysgeusia, anosmia) Three (2 7%) patients tested positive for COVID-9 after the procedures None of them required hospitalization CONCLUSION: Following a 2-week follow up, we identified only 3 out of 112 patients who become COVID-19 positive following an endoscopic procedure Our results indicate a potentially low risk of COVID-19 transmission for patients undergoing GI endoscopy

Introduction Lumen apposing metal stents (LAMS) have been used increasingly for drainage of pancreatic fluid collections (PFC). We present an international, multicenter study evaluating the safety and efficacy of LAMS in PFCs. Methods Consecutive patients undergoing LAMS placement for PFC at 12 international centers were included ( ClinicalTrials.gov NCT01522573). Demographics, clinical history, and procedural details were recorded. Technical success was defined as successful LAMS deployment. Clinical success was defined as PFC resolution at three-month follow-up. Results 192 patients were included (140 males (72.9%), mean-age 53.8 years), with mean follow-up of 4.2 months ± 3.8. Mean PFC size was 11.9 cm (range 2–25). The median number of endoscopic interventions was 2 (range 1–14). Etiologies for PFC were gallstone (n = 82, 42.7%), alcohol (n = 50, 26%), idiopathic (n = 26, 13.5%), and other (n = 34, 17.7%). Technical success was achieved in 189 patients (98.4%). Clinical success was observed in 125 of 135 patients (92.6%). Adverse events included bleeding (n = 11, 5.7), infection (n = 2, 1%), and perforation (n = 2, 1%). Three or more endoscopy sessions were a positive predictor for PFC resolution and the only significant predictor for AEs. Conclusion LAMS has a high technical and clinical success rate with a low rate of AEs. PFC drainage via LAMS provides a minimally invasive, safe, and efficacious procedure for PFC resolution.

It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs.We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available.The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P.001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P.001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P.001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P.001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P = .04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%).In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA-even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509.

Background and study aims Endoscopic drainage with dedicated lumen-apposing metal stents (LAMS) is routinely performed for symptomatic pancreatic fluid collections (PFCs), walled-off necrosis (WON) and pseudocyst (PP). There has been increasing concern regarding delayed adverse events associated with the indwelling LAMS. Patients and methods Multicenter retrospective analysis of consecutive patients who underwent endoscopic ultrasound (EUS)-guided LAMS placement for PFC from January 2010 to May 2017. Main outcomes included: (1) resolution of the PFC, (2) rate of delayed adverse events at follow-up, and (3) predictors of treatment failure and delayed adverse events on logistic regression. Results A total of 122 patients (mean age 50.9 years, 68 % male) underwent LAMS insertion for 64 WON (98.4 %) and 58 PP (98.3 %). PFC mean size was 10.6 cm. PFC resolution was significantly lower for WON (62.3 %) vs. PP (96.5 %) (P Conclusions EUS-guided LAMS for PFC is associated with a low incidence of delayed adverse events. While nearly all PPs resolve at 4 weeks permitting LAMS removal shortly thereafter, many WON persist, with use of electrocautery-enhanced LAMS being the sole predictor of treatment failure.