Could platelet mass index (PMI) be a new prognostic biomarker for COVID-19?

Aim: Although most patients with COVID-19 experience respiratory tract infections, severe reactions to the virus may cause coagulation abnormalities that mimic other systemic coagulopathies associated with severe infections, such as disseminated intravascular coagulation and thrombotic microangiopathy. Fluctuations in platelet markers, which are an indicator of the acute phase response for COVID-19, are of clinical importance. The aim of this study is to evaluate the relationship between disease severity and Platelet Mass Index (MPI) parameters in COVID-19 patients. Material(s) and Method(s): This retrospective observational study was conducted with patients who were diagnosed with COVID-19 in a tertiary hospital. The study was continued with the remaining 280 patients. All laboratory data were scanned retrospectively from patient files and hospital information system. Result(s): A very high positive correlation was found between PMI and PLT. The PMI value in women was significantly higher than in men. It was observed that PMI did not differ significantly in terms of mortality, intubation, CPAP and comorbidity. PMI vs. Pneumonia Ct Severity Score, biochemistry parameters (AST, CRP), hemogram parameters (WBC, HGB, HCT, MCV, LYM, MPV EO) and coagulation factors (aPTT and FIB) at various levels of positive/negative, weak and strong, and significant relationship was found. There was no significant relationship between hormone and D-dimer when compared with PMI. Discussion(s): Although platelet count alone does not provide information about the prognosis of the disease, PMI may guide the clinician as an indicator of lung damage in seriously ill patients.Copyright © 2022, Derman Medical Publishing. All rights reserved.

COVID-19 during the Third Semester of Pregnancy: Maternal Characteristic, Possibility of Intrauterine Transmission and Neonatal Outcome in Aceh, Indonesia

BACKGROUND: Pregnant women are vulnerable against COVID-19 infection due to physiological and immunological changes. COVID-19 in pregnancy affects fetal well-being with a potential for vertical infection. AIM: This study aims to determine the incidence of vertical infection and anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in infants born to mothers with positive COVID-19 infection. MATERIALS AND METHODS: Amniotic fluid, swabs of the newborn's nasopharynx and oropharynx, and swabs of the placenta were examined using reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2. Serological examination was performed by Electro-Chemiluminescence Immunoassay on infant's blood. RESULT(S): Four of 33 pregnant women gave birth to infants positive SARS-CoV-2 infection. RT-PCR examination of all amniotic fluid and placental swabs was negative for SARS-CoV-2. Four of 33 infants (12.1%) showed negative polymerase chain reaction (PCR) results but positive SARS-CoV-2 antibodies, another 4 newborns (12.1%) showed positive PCR results, but no SARS-CoV-2 antibodies detected. The remaining 25 babies (75.8%) showed both negative PCR and serologic results. CONCLUSION(S): No evidence of vertical transmission found in this study.Copyright © 2023 Cut Meurah Yeni, Zinatul Hayati, Sarjani M. Ali, Hasanuddin Hasanuddin, Rusnaidi Rusnaidi, Cut Rika Maharani.

Bilateral Spontaneous Pneumothorax in a Child with Multisystem Inflammatory Syndrome Associated with COVID-19

Introduction: Spontaneous pneumothorax is a rare complication of coronavirus disease 2019 (COVID-19), primarily reported in adults. Pediatric cases with bilateral pneumothorax are much less reported. Case Presentation: We presented the case of a five-year-old previously healthy boy who developed persistent fever, abdominal pain, generalized maculopapular rash, and dyspnea before admission. His chest computed tomography (CT) showed a viral involvement pattern of pneumonia suggestive of COVID-19. Subsequently, he was confirmed with multisystem inflammatory syndrome in children (MIS-C). While he responded well to the therapies, on the fifth day of admission, he developed respiratory distress again. A chest roentgenogram showed bilateral spontaneous pneumothorax. Bilateral chest tubes were inserted, and his condition improved sig-nificantly after five days of admission to the intensive care unit. Two weeks later, he was discharged in good condition. Conclusion(s): Children with MIS-C associated with COVID-19 may develop primary spontaneous pneumothorax. Owing to the clinical picture overlapping with MIS-C associated with COVID-19, the timely diagnosis of pneumothorax may be challenging in such patients.Copyright © 2022, Author(s).

Establishment of an infrastructure for rapid pandemic response at the Frederick National Laboratory

The sudden onset of the 2019 SARS-CoV-2 pandemic required agile development of standards and efficient validation of assays to assess prevalence of infection as well as immune responses to infection and vaccination. Leveraging their experience in HPV serology and standards, the Vaccine, Immunity and Cancer Directorate (VICD) at the Frederick National Laboratory for Cancer Research (FNCLR) pivoted to address this unmet need in SARS-Co-V2 serology clinical testing and research. This standardization effort required the collection and processing of large volumes of blood from SARS-Co-V2 infected and uninfected individuals into serum and peripheral blood mononuclear cells (PBMCs). Collaborations with specimen collection sites across the United States were established. Following qualification for anti-SARS-CoV-2 IgG and IgM levels in independent laboratories, VICD assembled reference evaluation panels, which were used to assist the FDA's performance evaluation of commercial assays submitted for EUA approval. To date, 185 different shipments of the standard or validation panel have been sent to both domestic and international labs. These materials are also available to the SARS-CoV-2 serology community for assay calibration and performance evaluation which greatly facilitates assay data harmonization. In addition, the NCI Serological Sciences Network (SeroNet) was born from this initiative and expertise, resulting in the establishment of Capacity Building Centers (CBCs) for sample collection from different healthy, cancer and immunocompromised cohorts at Mount Sinai, Arizona State University, the University of Minnesota, and Northwell Feinstein. The NCI and FNLCR simultaneously collaborated to develop a network of investigators focused on advancing research on the immune response to SARS-CoV-2 infection and vaccination among diverse and vulnerable populations, including cancer patients. Their research has resulted in over 326 peer-reviewed publications. The CBC's have enrolled patients in longitudinal studies, resulting in a centralized collection of annotated, well characterized serum, PBMCs and clinical data. Numerous cancer cohorts, but predominantly Multiple Myeloma, are included. Furthermore, technology development was supported at the CBC's. Based upon this success, the VICD in collaboration with NCI is pursuing an even more innovative effort in pandemic preparedness to establish a Center for Serology and Data Emergency Preparedness (CESDEP);a global network able to activate and pivot to address pandemic-level threats, while continuing to expand the development of immunological assays that can inform clinical decisions for cancer and other immunocompromised patients.

T-cell mediated response to emerging COVID19 strains in patients with cancer studied via deep learning

Cancer patients, particularly those receiving B cell-depleting therapy for lymphoid malignancies, are at risk of prolonged SARS-CoV-2 infection, poorer clinical outcomes, and delayed initiation or disruption of cancer-directed therapy (Lee at al., 2022, Clark et al., 2021). We first studied T-cell mediated response to the Wuhan strain of SARS-CoV-2 in a cohort of 69 patients with hematologic and solid cancers, including 18 patients who received prior B-cell depleting therapy. Patients with prolonged COVID-19 clearance, defined by a positive PCR test for longer than 30 days, had a broad but poorly converged CD8+ dominant response and a lacking CD4+ response. To conduct this analysis, we performed bulk T-cell receptor (TCR) sequencing of 121 blood samples and tracked over time TCR repertoire statistics such as clonality, convergence, breadth, and depth of COVID-19-associated TCRs during the active and convalescent periods of COVID-19 infection. These SARS-CoV-2-associated TCRs were identified leveraging immunoSEQ T-MAP database (Snyder et al., 2020), a set of TCR sequences derived from COVID-19 patients and experimentally identified as responsive to MHC Class I and II epitopes from the Wuhan SARS-CoV-2 strain using the multiplex identification of TCR antigen assay (Klinger et al., 2015). To extend our TCR repertoire analysis to other SARS-CoV-2 variants, including Omicron, we developed a deep learning (DL) method to predict TCR specificities for new SARS-CoV-2 epitopes. This DL approach also permits the identification of SARS-CoV2-responsive TCRs private to an individual. Combining this DL approach with our TCR statistics methodology, we studied the dynamics of T-cell response to COVID-19 vaccinations in a cohort of 50 patients with cancer and analyzed TCR repertoire characteristics associated with different degrees of COVID-19 severity in a cohort of 42 cancer patients who contracted the Omicron. Understanding cellular response to novel infections is critical for patient care in the context of cancer, and our novel DL-based approach can leverage existing datasets to analyze and track response to emerging viral strains.

The Impact of Sputnik SARS-CoV-2 Vaccines on Antibody Response in the Egyptian Population

BACKGROUND: The coronavirus disease 2019 (COVID-2019) causes the severe contagious acute respiratory syndrome. Therefore, massive vaccination campaign is mandatory to control the spread. Sputnik COVID-19 vaccines induce immunity through different mechanisms involving antibody response that bind to the spike protein to neutralize the viral entry into the cells. AIM: This study aims to compare the titers of specific antibodies in the pre-and post-vaccination sera in the vaccinated Egyptian population to evaluate the efficacy of the sputnik vaccine. METHOD(S): Samples were collected from 205 adult volunteers receiving the Sputnik vaccine in the Reference Laboratory of Egyptian University Hospitals. Samples were collected before vaccination and within 1, 2, or 3 months after receiving two doses of Sputnik SARS-CoV-2 vaccines from August to October 2021, serum samples collected were tested by quantitative chemiluminescent immunoassay using (Mindray CL-960i chemiluminescence analyzer, India) at the Reference laboratory of Egyptian University Hospitals for neutralizing antibodies, anti-spike antibodies, and total antibody levels before and after vaccination. RESULT(S): The results of the 205 paired samples illustrated that there was a statistically significant difference between pre-and post-vaccination antibody levels with a p-value of (< 0.001) indicating that the vaccine produced significantly high levels of antibodies. CONCLUSION(S): COVID-19 Sputnik vaccines induce immunity through an antibody response that binds to the virus to neutralize its entry into cells. Our study showed a significant increase in the measured post-vaccination levels of the three antibodies among the enrolled volunteers compared to the basal pre-vaccination level and thus sputnik vaccine protects against SARS-CoV-2 infections.Copyright © 2023 Ghada Ismail, Dalia Abdelhamid, Marwa Salah Mostafa, Noha Alaa Eldin Fahim, Ahmed Elshafei, Hossam Abdelghaffar, Nashwa Naguib, Omnia Taher, Menna Asker.

Detection of SARS-CoV-2 Antibodies in Matched Pregnant Women and Newborn Blood

Objective: The factors affecting the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies from mother to newborn and the duration of seropositivity rates in these infants have not yet been clearly demonstrated. The objectives of this study were (1) to assess the levels of SARS-CoV-2 spike-specific immunoglobulin G (IgG) in women infected in the pregnancy period and newborns born to these women and (2) to search the transplacental transfer ratio of spike-specific IgG. Method(s): Seventy pregnant women with symptomatic SARS-CoV-2 infection and their newborns were prospectively followed. Anti-SARS-CoV-2 immunoassay was used for the detection of the in vitro quantitative determination of total antibodies to the SARS-CoV-2 spike protein. Discussion(s): Spike-specific IgG was demonstrated in 89.1% (44 of 46) of pregnant women infected more than 14 days before delivery and in 92.6% (43 of 44) of their newborns. Median transfer ratio of spike-specific Ig was 0.87 (interquartile range [IQR], 0.34-0.90), 1.0 (IQR, 0.9-0.29), and 0.81 (IQR, 0.02-1.0) in first trimester (n = 4), second trimester (n = 14), and third trimester (n = 28) pregnant women, respectively. Antibody transfer ratio was correlated with time elapsed from infection (p < 0.001). Peak antibody transfer ratio above 1 was observed at a median 60 to 120 days after the infection from delivery. Antibody transfer ratio was high in pregnant women infected more than 60 days before delivery (p < 0.001). Transfer ratio was significantly higher in the severe-critically symptomatic women (n = 15) than the mild-moderately symptomatic women (n = 55) (p = 0.001). At 3 months, 18 of 25 infants (72%) had spike-specific IgG. Conclusion(s): Timing from infection to delivery and severity of maternal infection are critical in assessing the antibody generation and transport. Higher antibody transfer ratio can be detected in neonates when SARS-CoV-2 infection is present for more than 60 days before birth. Maternally derived antibody can persist for 3 months after birth.Copyright © 2023. The Author(s).

Liquid biopsy testing in metastatic or advanced breast cancer patients during the COVID-19 pandemic

Objective: During the COVID-19 pandemic, cancer patients had restricted access to standard of care tissue biopsy. Liquid biopsy assays using next generation sequencing technology provides a less invasive method for determining circulating tumour mutations (ctDNA) associated with targeted treatments or prognosis. As part of deploying technology to help cancer patients obtain molecular testing, a clinical program was initiated to offer liquid biopsy testing for Canadian patients with advanced or metastatic breast cancer. Method(s): Blood was drawn in two 10 mL StreckTM DNA BCTs and sent to the CAP/CLIA/DAP accredited Imagia Canexia Health laboratory for testing using the clinically validated Follow ItTM liquid biopsy assay. Plasma was isolated using a double spin protocol and plasma cell-free DNA (cfDNA) extracted using an optimized Promega Maxwell RSC method. Extracted cfDNA was amplified using the multiplex amplicon-based hotspot 30 or 38 gene panel and sequenced. An inhouse developed bioinformatics pipeline and reporting platform were used to identify pathogenic single nucleotide variants (SNVs), indels (insertions and deletions), and gene amplification. Included in the panel are genes associated with metastatic breast cancer: AKT1, BRAF, ERBB2, ESR1, KRAS, PIK3CA, TP53. Result(s): To identify biomarkers, 1214 metastatic or advanced breast cancer patient cfDNA samples were tested. There were 15 cases sent for repeat testing. We reported 48% of samples harboring pathogenic ctDNA mutations in TP53 (22%), PIK3CA (19%), ESR1 (18%), AKT1 (2%), ERBB2 (1.5%). Co-occurring variants were identified in samples with ESR1/PIK3CA as well as TP53/PIK3CA (both p-values <0.001). Interestingly, 29% of samples with mutated ESR1 harbored >= 2 ESR1 ctDNA mutations. In 56% of cases, previous molecular testing indicated the cancer subtype as hormone receptor (ER, PR) positive with/without HER2 negative status. In this specific subgroup, 49% harbored ctDNA mutations with 63% of those being PIK3CA and/or ESR1 mutations. Conclusion(s): A population of Canadian women with metastatic breast cancer were tested using a liquid biopsy gene panel during the COVID-19 pandemic for identification of biomarkers for targeted therapeutic options. Over 50% of the samples were identified as hormone positive, with greater than 60% harboring PIK3CA and ESR1 ctDNA mutations. Studies have shown that metastatic PIK3CA mutated ER-positive/HER2-negative tumors are predictive to respond to alpelisib therapy and have FDA and Health Canada approval. Additionally, ESR1 mutations are associated with acquired resistance to antiestrogen therapies, and interestingly we identified 29% of ESR1 mutated samples with multiple mutations possibly indicating resistance subclones. In future studies, longitudinal monitoring for presence of multiple targetable and resistance mutations could be utilized to predict or improve clinical management.

Monitoring SARS CoV-2 antibodies positivity in healthcare workers after inactivated CoronaVac vaccine

Introduction In this study, we aimed to monitor anti-spike and anti-nucleocapsid antibodies positivity in healthcare workers (HCWs) vaccinated with two doses of inactivated CoronaVac (Sinovac, China) vaccine. Methods Overall, 242 volunteer HCWs were included. Of the participants, 193 were HCWs without history of prior documented COVID-19 (Group 1), while 49 had history of prior documented COVID-19 before vaccination (Group 2). The participants were followed up for SARS-CoV-2 antibodies positivity at four different blood sampling time points (immediately before the second vaccine dose and at the 1st, 3rd months and 141-150 days after the second dose). We investigated the serum IgG class antibodies against SARS-CoV-2 RBD region and IgG class antibodies against SARS-CoV-2 nucleocapsid antigen by chemiluminescent microparticle immunoassay (CMIA) method using commercial kits. Results We found positive serum anti-RBD IgG antibody in 76.4% of the participants (71% in Group 1;98% in Group 2) 28 days after the first dose. When the antibody levels of the groups were compared at the four blood sampling time points, Group 2 anti-RBD IgG levels were found to be significantly higher than those in Group 1 at all follow-up time points. Although anti-RBD IgG positivity persisted in 95.6% of all participants in the last blood sampling time point, a significant decrease was observed in antibody levels compared to the previous blood sampling time point. Anti-nucleocapsid IgG antibody was positive in 12 (6.2%) of participants in Group 1 and 32 (65.3%) in Group 2 at day 28 after the first dose. At the fourth blood sampling time point, anti-nucleocapsid antibodies were found to be positive in a total of 20 (9.7%) subjects, 10 (6.1%) in Group 1 and 10 (23.8%) in Group 2. Conclusions In this study, it was determined that serum antibody levels decreased in both groups after the third month after the second dose in HCWs vaccinated with CoronaVac vaccine.Copyright © GERMS 2022.

Detection of SARS-CoV-2 antibodies among the pre-vaccine population in Bali

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of coronavirus disease 2019 (COVID-19), has affected millions of people globally. It is a very contagious disease with various clinical manifestations. However, even in asymptomatic patients, it is believed that this virus exposure induces cryptic antibodies as in symptomatic patients. This current study aims to assess the prevalence of SARS-CoV-2 seropositivity by detecting the antibodies specific to the receptor-binding domain (SRBD) of SARS-CoV-2 in the pre-vaccine population in Bali. We assessed specific antibody titers against trimeric spike glycoprotein (S) of SARS-CoV-2 using Roche Elecsys Anti-SARS-CoV-2 S immunoassay in the serum of 510 pre-vaccine subjects without a previous documented history of SARS-CoV-2 infection. The average age was 35.53 years with 56.7% of the subjects being male. Among 510 subjects, 190 (37.3%) subjects were detected to have SARS-CoV-2 SRBD antibody or be seropositive. The range of the antibody titer was zero to 250 U/mL with the average being 44.3 U/mL. The number of subjects who had anti-SARS-Cov-2 SRBD titer above 132 U/mL was 76 (14.9%);it was the minimal antibody titer needed to donate plasma for plasma convalescent therapy. This study revealed a pre-vaccination population, without a history of COVID-19 infection, with seropositivity to SARS-CoV-2, which indicates the underdiagnosis of COVID-19, especially in asymptomatic individuals.

Seroprevalence of anti-SARS-CoV-2 antibodies in high-risk occupational and low-risk groups in southwestern Iran

Background: Monitoring the spread of SARS-CoV-2 has been considered by the World Health Organization (WHO). We examined the prevalence of anti-SARS-CoV-2 immunoglobulin antibodies in southwestern Iran in spring 2020. The circulation of SARS-CoV-2 is high in the general population, especially among health care workers (HCWs) who are in close contact with patients. Objectives: The aim of this study was to determine the prevalence of anti-SARS-CoV-2 antigen in high-risk occupational and low-risk groups to investigate risk factors for serum positivity in Shiraz, southwestern Iran. Methods: A cross-sectional survey was performed on 366 participants (204 from high-risk and 162 from low-risk subjects). IgG and IgM antibodies were detected using Pishtaz Teb COVID-19 ELISA Kits to evaluate SARS-CoV-2-antigen in serum samples. After enzyme-linked immunosorbent assay (ELISA), serum prevalence, as well as IgG/IgM positive factors, was determined using logistic regression. Results: From July to September 2020 (a few months after reporting the first case of COVID-19 cases in Iran), out of 366 survived people, 72 (40.9%) were IgG positive, and 50 (27.5%) were IgM positive. The frequency of positive serology for IgG and IgM antibodies in individuals aged < 30 years was higher in the low-risk group than in the high-risk group. Multivariate logistic regression showed that headache (OR 0.312 [95% CI: 0.136 - 0.717]) and cough (OR 0.427 [95% CI: 0.182 - 1.004]) factors were associated with IgG or IgM positive serology. Conclusions: Between July and September 2020, the prevalence of anti-SARS-CoV-2 antigen was high in Shiraz. The prevalence of SARS-CoV-2 IgG/IgM antibodies in the high-risk group and their family as low risk was shown to increase viral infection due to close contact with COVID 19 patients than in the general population. Several factors were found to be related to the prevalence of anti-SARS-CoV-2 antigen that needs to be considered by policymakers to determine what to do about the SARS-CoV-2 pandemic.

SARS-Cov-2 Spike-S1 Antigen Test Strip with High Sensitivity Endowed by High-Affinity Antibodies and Brightly Fluorescent QDs/Silica Nanospheres.

The extensive research into developing novel strategies for detecting respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in clinical specimens, especially the sensitive point-of-care testing method, is still urgently needed to reach rapid screening of viral infections. Herein, a new lateral flow immunoassay (LFIA) platform was reported for the detection of SARS-CoV-2 spike-S1 protein antigens, in which four sensitive and specific SARS-CoV-2 mouse monoclonal antibodies (MmAbs) were tailored by using quantum dot (QD)-loaded dendritic mesoporous silica nanoparticles modified further for achieving the -COOH group surface coating (named Q/S-COOH nanospheres). Importantly, compact QD adsorption was achieved in mesoporous channels of silica nanoparticles on account of highly accessible central-radial pores and electrostatic interactions, leading to significant signal amplification. As such, a limit of detection for SARS-CoV-2 spike-S1 testing was found to be 0.03 ng/mL, which is lower compared with those of AuNPs-LFIA (traditional colloidal gold nanoparticles, Au NPs) and enzyme-linked immunosorbent assay methods. These results show that optimizing the affinity of antibody and the intensity of fluorescent nanospheres simultaneously is of great significance to improve the sensitivity of LFIA.

Evolution of the newest diagnostic methods for COVID-19: a Chinese perspective. / ä¸­å›½è§†è§’ä¸‹çš„æ–°å† è‚ºç‚Žæœ€æ–°è¯Šæ–­æ–¹æ³•æ¼”è¿›.

Coronavirus disease 2019 (COVID-19) has continued to spread globally since late 2019, representing a formidable challenge to the world's healthcare systems, wreaking havoc, and spreading rapidly through human contact. With fever, fatigue, and a persistent dry cough being the hallmark symptoms, this disease threatened to destabilize the delicate balance of our global community. Rapid and accurate diagnosis of COVID-19 is a prerequisite for understanding the number of confirmed cases in the world or a region, and an important factor in epidemic assessment and the development of control measures. It also plays a crucial role in ensuring that patients receive the appropriate medical treatment, leading to optimal patient care. Reverse transcription-polymerase chain reaction (RT-PCR) technology is currently the most mature method for detecting viral nucleic acids, but it has many drawbacks. Meanwhile, a variety of COVID-19 detection methods, including molecular biological diagnostic, immunodiagnostic, imaging, and artificial intelligence methods have been developed and applied in clinical practice to meet diverse scenarios and needs. These methods can help clinicians diagnose and treat COVID-19 patients. This review describes the variety of such methods used in China, providing an important reference in the field of the clinical diagnosis of COVID-19.

Recent Trends in Lateral Flow Immunoassays with Optical Nanoparticles.

Rapid, accurate, and convenient diagnosis is essential for effective disease management. Various detection methods, such as enzyme-linked immunosorbent assay, have been extensively used, with lateral flow immunoassay (LFIA) recently emerging as a major diagnostic tool. Nanoparticles (NPs) with characteristic optical properties are used as probes for LFIA, and researchers have presented various types of optical NPs with modified optical properties. Herein, we review the literature on LFIA with optical NPs for the detection of specific targets in the context of diagnostics.

Seroprofiling of antibodies against endemic human coronaviruses and SARS-CoV-2 in an HIV cohort in Lesotho: correlates of antibody response and seropositivity.

BACKGROUND: Serological data on endemic human coronaviruses (HCoVs) and SARS-CoV-2 in southern Africa are scarce. Here, we report on i) endemic HCoV seasonality, ii) SARS-CoV-2 seroprevalence, and iii) predictive factors for SARS-CoV-2 seropositivity and strength of SARS-CoV-2 and HCoV serological response during a 17-month period at the start of the COVID-19 pandemic among adults living with HIV. METHODS: Plasma samples were collected from February 2020 to July 2021 within an outpatient HIV cohort in Lesotho. We used the ABCORA multiplex immunoassay to measure antibody responses to endemic HCoV (OC43, HKU1, NL63, and 229E) and SARS-CoV-2 antigens. RESULTS: Results of 3'173 samples from 1'403 adults were included. Serological responses against endemic HCoVs increased over time and peaked in winter/spring. SARS-CoV-2 seropositivity reached >35% among samples collected in early 2021 and was associated with female sex (p = 0.004), obesity (p < 0.001), working outside the home (p = 0.02), and recent tiredness (p = 0.005) or fever (p = 0.007). Positive correlations were observed between the strength of response to endemic HCoVs and to SARS-CoV-2, and between older age or obesity and the IgG response to SARS-CoV-2. CONCLUSIONS: These results add to our understanding of the impact of biological, clinical, and social/behavioural factors on serological responses to coronaviruses in southern Africa.

Advancements in portable instruments based on affinity-capture-migration and affinity-capture-separation for use in clinical testing and life science applications.

The shift from testing at centralized diagnostic laboratories to remote locations is being driven by the development of point-of-care (POC) instruments and represents a transformative moment in medicine. POC instruments address the need for rapid results that can inform faster therapeutic decisions and interventions. These instruments are especially valuable in the field, such as in an ambulance, or in remote and rural locations. The development of telehealth, enabled by advancements in digital technologies like smartphones and cloud computing, is also aiding in this evolution, allowing medical professionals to provide care remotely, potentially reducing healthcare costs and improving patient longevity. One notable POC device is the lateral flow immunoassay (LFIA), which played a major role in addressing the COVID-19 pandemic due to its ease of use, rapid analysis time, and low cost. However, LFIA tests exhibit relatively low analytical sensitivity and provide semi-quantitative information, indicating either a positive, negative, or inconclusive result, which can be attributed to its one-dimensional format. Immunoaffinity capillary electrophoresis (IACE), on the other hand, offers a two-dimensional format that includes an affinity-capture step of one or more matrix constituents followed by release and electrophoretic separation. The method provides greater analytical sensitivity, and quantitative information, thereby reducing the rate of false positives, false negatives, and inconclusive results. Combining LFIA and IACE technologies can thus provide an effective and economical solution for screening, confirming results, and monitoring patient progress, representing a key strategy in advancing diagnostics in healthcare.

Cuban Vaccines Abdala and Mambisa against Covid-19

Intro: With the first case of COVID-19 in Cuba on March 11, 2020, the Center for Genetic Engineering and Biotechnology in Havana began an extensive vaccine program. Two vaccines based on RBD recombinant protein were developed, one for systemic administration "Abdala" and one mucosal vaccine "Mambisa". Abdala received the EUA in July 2021 and "Mambisa" completed its clinical development as a booster dose for convalescent subjects. Method(s): Two doses (25 and 50 microg) and two schedules (0-14-28 and 1-28-56 days) were evaluated in phase I clinical trials with volunteers 19 to 54 years old. The phase II and III clinical trials were also double-blind, randomized, and placebo-controlled, and included respectively 660 and 48,000 volunteers from 19 to 80 years. The anti-RBD titers were evaluated using a quantitative ELISA system developed at the Center for Immunoassay, Havana Cuba, and ELECSYS system from Roche. The RBD to ACE2 plate-based binding competitive ELISA was performed to determine the inhibitory activity of the anti-RBD polyclonal sera on the binding of the hFc-ACE2 coated plates. The neutralization antibody titers were detected by a traditional virus microneutralization assay (MN50). Finding(s): The Abdala vaccine reached 92.28% efficacy. The epidemic was frankly under control in Cuba after the vaccine introduction having reached the highest levels of cases and mortality in July 2021 with the dominance of the Delta strain. The peak of the Omicron wave, unlike other countries, did not reach half of the cases of the Delta wave with a significant reduction in mortality. The mucosal vaccine candidate "Mambisa" completed its clinical development as a booster dose for convalescent subjects reaching the trial end-point. Conclusion(s): Vaccine composition based on RBD recombinant antigen alone is sufficient to achieve high vaccine efficacy comparable to mRNA and live vaccine platforms. The vaccine also protects against different viral variants including Delta and Omicron strains.Copyright © 2023

Relationship between Sars-Cov-2 Viral Load, Antigen Positivity and Infectious Titer

Intro: Performance of SARS-CoV-2 antigen tests is described relative to RT-PCR cycle threshold (Ct) values. However, Ct values may not be consistent between tests from different manufacturers, or even between runs. Here we correlate the Roche Elecsys SARS-CoV-2 Antigen assay results to a quantitative RT-PCR readout as a more reproducible measure of viral load. Additionally, we look at the relationship between the antigen test results, viral load and infectious titer. Method(s): Longitudinal nasopharyngeal swab samples from patients (N=452) with severe Covid-19 pneumonia collected between 03 April and 28 May 2020 in a randomized, double-blind, placebo controlled, multicenter study to evaluate the safety and efficacy of Tocilizumab (COVACTA), were assessed for SARS-CoV-2 viral load (RNA copies/ mL) and a qualitative and semi-quantitative readout of Elecsys SARS-CoV-2 Antigen assay. Viral culture experiments were performed to determine the infectious titer (TCID50/ mL) in a subset of samples. Agreement analysis was performed to compare the results of the assays. Please note that the current intended use of Elecsys SARS-CoV-2 Antigen assay is the qualitative detection of SARS-CoV-2 antigen. Finding(s): We observed high negative percent agreement between the Elecsys SARS-CoV-2 Antigen assay results and the RT-PCR results, while the positive percent agreement was only high in samples exceeding a certain viral load and at earlier time points from symptom onset. Infectious titer values and both the antigen assay semi-quantitative readout and the quantitative RT-PCR results correlated well. Positive percent agreement of RT-PCR and antigen results in relation to infectious titer was very high in both cases, while negative percent agreement was moderate to low. Conclusion(s): These data show that in patients with high viral load the Elecsys SARS-CoV-2 Antigen assay correlates well qualitatively and quantitatively with the presence of SARS-CoV-2 RNA and infectious virus as determined by RT-PCR and viral culture, respectively.Copyright © 2023

Cooperate with community health centers to eliminate HCV in low prevalence region of South China

Background: Shenzhen, a city of immigrants in South China, has a low HCV incidence rate of 19.47 per 100,000. To eliminate HCV in this low prevalence region, it may be efficiency to collaborate with the communities to screen HCV in high risk population. There are 849 Community Health Centers up to now in Shenzhen. The study aimed to evaluate the model of HCV elimination in high-risk population with Community Health Centers. Method(s): The Shenzhen Medical Association assigned hepatologists to educate Primary Care Physicians (PCPs) of 13 Community Health Centers in Bao'an District from 2021.6-2022.6. The PCPs need to take HCV knowledge tests before and after the training. Only when all the questions are answered correctly can the test be passed. Then they recommend the high risk population, e.g., PWID, pricking wound, iatrogenic exposure, to do the HCV antibody test and transfer the patients with HCV-Ab (+) to the hepatologist of Shenzhen Bao'an People's Hospital. Result(s): 151 PCPs participated in HCV knowledge education, the pass rate improved from 15.2% to 53.8% after the training. The high risk population screening number in Community Health Centers improved from 192 (a year before) to 300, even affected by the lockdown of COVID-19. The HCV antibody positive rate in high risk population is 4% (12/300), higher than the hospital population (0.8%, Shenzhen Bao'an People's Hospital), the blood donor (0.3%, Shenzhen Blood Center). The HCV-Ab positive patients in communities transferred to Shenzhen Bao'an People's Hospital, where the rate of DAA treatment is improved from 36.6% (a year before) to 64.1%. Conclusion(s): It is an efficient way to achieve HCV elimination earlier to screening in high risk population through PCPs in low prevalence region. Expanding this model to other Community Health Centers in Shenzhen may accelerate HCV elimination. (Figure Presented).

Persistence and Dynamicity of Sars-Cov-2 Antibody Response after Double Dose of Bbv-152 and Azd1222 Vaccines: A Prospective, Longitudinal, Year-Long Cohort Study

Intro: Different vaccines against COVID-19 have been approved by the World Health Organization (WHO) at different stages, however, limited data is available on long-term kinetics of antibodies induced by vaccines. This study was performed to investigate the persistence and dynamicity of BBV-152 (Covaxin)- and AZD1222 (Covishield)-induced immunoglobulin-G (IgG) antibodies over the year and neutralizing antibodies' status after the one-month post booster dose. Method(s): This 52-week longitudinal cohort study documented antibody persistence and neutralizing antibody status among 278 health-care workers (HCWs) from four different healthcare and research facilities in Odisha, enrolled in January 2021 and continued until March 2022. An automated chemiluminescence immune assay (CLIA) platform from Abbott Diagnostics was used to quantify IgG antibodies against SARS-CoV-2's spike receptor-binding domain (RBD) and a surrogate virus neutralization test (sVNT) was performed by enzyme-linked immunosorbent assay (ELISA). If any participants developed any symptoms of COVID-19, nasopharyngeal swabs were collected and sent to ICMR- RMRC, Bhubaneswar for RT-PCR confirmation. Finding(s): Among the 243 participants, 119 HCWs (48.97%) were Covaxin recipients and the remaining 124 (51.02%) were Covishield recipients. During the seven follow- ups, 104 participants (42.79%) were identified as vaccine breakthrough cases. In 139 non-infected HCWs, the median antibody titer significantly waned after ten months of double dose, both for Covaxin (342.7 AU/mL at DD1 vs 43.9 AU/mL at DD10) and Covishield (2325.8 AU/mL at DD3 vs 595.2 AU/mL at DD10). No statistically significant differences in antibody titers were observed based on age, gender, comorbidities, and blood groups. The median inhibition activity of sVNT was increased significantly for Covaxin and Covishield booster recipients. Among the booster dose recipients, 24 had breakthrough cases by the Omicron variant. Conclusion(s): Results of this longitudinal cohort study can be used to implement vaccination strategies and could also aid in tracking and designing vaccine mandates to minimize vaccine escape.Copyright © 2023