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Intro: The COVID-19 pandemic is caused by the SARS-CoV-2 virus, an enveloped RNA of the coronavirus family. The advancement in molecular technology and biochemistry has accelerated the development of diagnostic reagents and assays. Much attention has been focused on the S protein, but the high mutation rate in this region could lead to false negative results. Thus, a better target protein for diagnostic application is needed for accurate detection. Method(s): Nucleotide sequences encoded for membrane (M) glycoprotein gene region of SARS-CoV-2 from Malaysian isolates were extracted from GISAID, aligned, and selected accordingly. The DNA plasmid was commercially synthesized with codon optimization for Escherichia coli (E. coli), and the presence of the M gene was confirmed by PCR. The plasmid was then transformed into E. coli. Later, the expression of M glycoprotein was induced, separated on an SDS-PAGE gel, and transferred onto a nitrocellulose membrane, followed by immunostaining. Finding(s): The analysis of the M glycoprotein against the Omicron strains demonstrated that the amino acid is conserved (99.5%). The M glycoprotein was successfully expressed and detected with antibodies from SARS-CoV-2 infected patients at ~26 kDa. The protein is currently upscale for the generation of monoclonal Ab (Mab). Discussion(s): The M protein of SARS-CoV-2 is more conserved among the virus and also has been reported to confer antigenic properties. Selection of M protein perhaps a better option compared to current detection assays that use spike (S) protein, which could lead to false negative results, as this gene region particularly the ribosome-binding domain (RBD) rapidly undergoes mutations. The utilization of M protein potentially improves negative predictive value (NPV) of the diagnostic test. Conclusion(s): Further development of diagnostic reagents is needed to improve the assay's specificity. The newly developed M protein and the MAb can be used to generate a more accurate viral detection assay.Copyright © 2023
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Introduction: Malaysia's National Polio Laboratory (NPL) has been appointed as the National Poliovirus Containment Coordinator (NPCC) in 2000 to minimize the number of facilities retaining potentially infectious materials, poliovirus (PIM). PIM is defined as respiratory, faecal, or environmental sewage samples, and derivatives such as permissible poliovirus cell culture, Oral Polio Vaccine (OPV), collected for any purpose before 31 December 2020. However, all monitoring activities were disrupted by the COVID-19 pandemic in early 2020. In addition, Polio outbreaks occurred in Sabah and WP Labuan at the same time which leads to the large-scale use of OPV to respond to widespread vaccine-derived poliovirus (VDPV) outbreaks, it could generate new PIM, which requires an update in the NPCC record database. Material(s) and Method(s): The main objective of the study is to ensure compliance of all country states to the requirement of the Global Polio Eradication Initiative (GPEI) by WHO by providing a database and evidence of action. As per the WHO Global Action Plan III (GAP III) guidelines, meetings and site visits were conducted with the government and non-government bodies that are keeping and handling PIM. In 2019, 588 survey forms were sent to 141 government hospitals, 6 government agencies (veterinary, fishery, chemical, research institutions), 19 major private laboratories, 209 private hospitals, and 16 public universities. Result(s): Out of the 588 facilities that received the survey forms, only 177 facilities have completed the survey. 173 facilities declared that they did not store any PIM, whilst 4 institutions had informed that they had completed inventories for their PIM storage and had discarded the identified materials accordingly. The other 411 facilities have informed the NPCC that they did not have any PIM and are still completing the survey forms. Conclusion(s): The NPCC actively adhered to the recommendation by GAP III guidelines for the containment activities by conducting national surveys, laboratory inspections, consultations, and inventories of records. Based on the findings, most of the laboratories that responded to the survey did not keep any PIM and follow the procedures as per the guideline. Continuous monitoring of PIM is required although the Polio outbreak was declared ended on 9th September 2021 in Malaysia. This study will be a reference for future planning by the ministry and authorities with regards of the Biosafety and Biosecurity regulations involving laboratories working with infectious materials.
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We studied the clinical and immunological outcomes of covid-19 infection in strictly consecutive patients with CLL from a well-defined area during the first 13 months of the pandemic. Sixty patients with a median age of 71 years (range 43-97) were identified. Median CIRS was 8 (4-20), median BMI 25 (19-42) and 65% were men. Patients had indolent CLL (n=38), were previously treated (n=12) or had ongoing therapy (n=10, among which seven received BTKi). Forty-six patients (77%) were hospitalized due to severe covid-19 and among them, 11 (24%) were admitted to the intensive care unit (ICU). Severe covid-19 was equally distributed across subgroups irrespective of age, gender, BMI, CLL status except for comorbidities (CIRS >6, p<0.05). Fourteen patients (23%) died;age ≥75 years was the only significant risk factor (p<0.05, uni- and multivariate analyses). Comparing months 1-6 vs. 7-13 of the pandemic, death rates were reduced from 32 to 18%, ICU admission from 37 to 15% and hospitalizations remained frequent (86 vs. 71%). Seroconversion occurred in 34/41 tested patients (83%) and anti-SARS-CoV-2 antibodies remained detectable at 6 and 12 months of follow-up in 17/22 and 8/11 patients, respectively. In-depth immunological analysis revealed that 13/17 tested patients had neutralizing antibodies (including all 12 patients that were also seropositive in conventional serology in this cohort), and 19/28 (68%) had antibodies in saliva. SARS-CoV- 2-specific T-cells (IFN-gamma ELISpot) were detected in 14/17 patients (82%). We conclude that covid-19 in non-selected CLL patients continued to result in a high admission rate even among young early-stage patients. A robust and durable B and/or T cell immunity was observed in most convalescents.
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Background and study design: Patients with immunodeficiencies including CLL have an increased risk of severe infections and may not respond well to conventional vaccines. Two early international surveys reported that hospital-admitted Covid-19 patients with CLL had a high fatality rate (Mato et al., 2020;Scarfo et al., 2020). We recently showed that a robust and durable B and/or T cell immunity occurred in most convalescent CLL patients (Blixt et al., 2021). In contrast, the first publication on vaccination against SARS-CoV-2 in CLL reported seroconversion in only 39.5% of patients (Herishanu et al., 2021). We conducted a prospective clinical trial (COVAXID, clinicaltrials.gov: NCT04780659) in patients with various types of immunodeficiency and matched controls (n=539). Five equally sized cohorts were included: primary immunodeficiency, HIV, allogeneic transplantation or CAR-T, solid organ transplantation as well as CLL. The primary endpoint was seroconversion measured 2 weeks after the 2nd dose of the Pfizer-BioNTech vaccine (Comirnaty). Antispike antibodies in saliva (which may better correlate with protection, Khoury et al., 2020) and T cells (IFN-gamma ELISpot) were also measured. We report here the results of the CLL cohort. Results: Ninety CLL patients were included in four predefined subgroups: indolent untreated disease (n=30);prior chemoimmunotherapy including a CD20 mAb 9-30 months ago (n=20);ongoing BTKi therapy (n=30);and stopped/paused ibrutinib (all >3 months ago) (n=10). The median age was 70 years (range 23-87) and 67% were men. Median IgG was 6.7 g/L (range 1.0-20.8) and 50% had a value below the lower normal range. Reactogenicity occurred in 82.9 and 77.1% of the CLL patients and 81.6 and 85.0% of the controls after doses 1 and 2, respectively. The severity of reactogenicity was similar in patients and controls. AEs≥grade 2 was seen in five patients within 2 weeks after dose 2 but none was considered related to the vaccine. No hematological toxicity was observed. Data analysis on seroconversion is ongoing. Preliminary analysis of saliva showed that on D35 (i.e. 14 days after 2nd dose) 62% of CLL patients (95% of healthy controls) had developed IgG to S1S2 spike antigen compared to only 23% on D21 (i.e. 21 days after dose 1). Subgroup analysis (D35) indicates that ibrutinib-treated patients showed the lowest response in saliva whilst indolent and prior chemoimmunotherapy-treated groups were the best responders. A different pattern was observed for IFNgamma positive T cells with the highest responses in the (few) patients who had paused/stopped ibrutinib with other subgroups having lower T cell responses. Conclusions: This prospective clinical trial verified that the BNT162b2 mRNA vaccine was well-tolerated in patients with CLL. Our preliminary results indicate that anti-spike antibodies in saliva and T cell responses were frequently observed after full vaccination but with different response patterns in CLL subgroups. Details of the study including seroconversion and the overall response rate will be presented at the meeting.
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No available.
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The COVID-19 pandemic has affected all individuals across the globe in some way. Despite large numbers of reported seroprevalence studies, there remains a limited understanding of how the magnitude and epitope utilization of the humoral immune response to SARS-CoV-2 viral anti-gens varies within populations following natural infection. Here, we designed a quantitative, multi-epitope protein microarray comprising various nucleocapsid protein structural motifs, including two structural domains and three intrinsically disordered regions. Quantitative data from the microarray provided complete differentiation between cases and pre-pandemic controls (100% sensitivity and specificity) in a case-control cohort (n = 100). We then assessed the influence of disease severity, age, and ethnicity on the strength and breadth of the humoral response in a multi-ethnic cohort (n = 138). As expected, patients with severe disease showed significantly higher antibody titers and interestingly also had significantly broader epitope coverage. A significant increase in antibody titer and epitope coverage was observed with increasing age, in both mild and severe disease, which is promising for vaccine efficacy in older individuals. Additionally, we observed significant differences in the breadth and strength of the humoral immune response in relation to ethnicity, which may reflect differences in genetic and lifestyle factors. Furthermore, our data enabled localization of the immuno-dominant epitope to the C-terminal structural domain of the viral nucleocapsid protein in two independent cohorts. Overall, we have designed, validated, and tested an advanced serological assay that enables accurate quantitation of the humoral response post natural infection and that has revealed unexpected differences in the magnitude and epitope utilization within a population.