Animal Pre-Clinical Study of an Inactivated SARS-CoV-2 Vaccine candidate (Osvid-19 ): Immunogenicity, Protective, and Safety Aspects

Background: This study aimed to evaluate the outcomes of preclinical studies on the safety and immunogenicity of an inactivated COVID-19 vaccine candidate to warrant further clinical evaluation. Method(s): SARS-CoV-2 positive nasopharyngeal swab specimens were confirmed by real-time polymerase chain reaction and next-generation sequencing. The safety and immunogenicity tests of the COVID-19 vaccine were carried out in rats and Rhesus monkeys, and Balb/C mice and Rhesus monkeys, respectively. Result(s): The candidate vaccine was well tolerated and induced promising levels of SARS-CoV-2- specific IgG1, IgG2a, and Granzyme B in Balb/C mice, and anti-SARS-CoV-2 spike IgG and neutralizing antibodies in Rhesus monkeys. Based on cVNT results, the inactivated vaccine in 0.5 and 1 microg/100 microL doses was able to induce a neutralizing effect against the SARS-CoV-2 virus up to a dilution of 1:512 and 1:1000. The protective efficacy of the vaccine candidate was challenged with 2 x108 PFU of live viruses and confirmed by lung CT scan and histopathological evaluations compared to the control group. Repeated intramuscular injection of the candidate vaccine was generally well-tolerated in Rats and Rhesuses. No significant side effects were observed in rats injected with ten full human doses and in the Rhesus monkeys with three full human doses. Conclusion(s): Based on the findings presented in this study, it is recommended that this vaccine be moved into human testing commencing with a phase I clinical trial.Copyright © 2021 Muslim OT et al.

Impact of Covid-19 and Host Factors on the Humoral Immune Repertoire in Treated Hiv

Background: People with HIV (PWH) on antiretroviral therapy (ART) appear to be at higher risk for worse COVID-19 outcomes, but the underlying mechanisms-including effects of COVID-19 and host factors on the broader humoral immune repertoire-are poorly understood. Method(s): REPRIEVE enrolled a global cohort of ART-treated PWH ages 40-75. COVID+ was defined by positive receptor binding domain IgG or IgA from annual visits 5/2020-2/2021. Antibody isotype, subclass, and Fc receptor Luminex arrays to SARS-CoV-2, CMV, EBV, HSV, HIV, influenza, pneumococcus, and RSV were assessed. Report of COVID diagnosis (collected every 4 months) was defined as mild, moderate, or severe (asymptomatic if no clinical diagnosis but IgG/ IgA+). FDR-corrected regression was used to assess effects of 1) COVID+ on non- SARS-CoV-2 repertoire in full cohort and 2) host factors on non-SARS-CoV-2 and SARS-CoV-2 repertoire in COVID- and COVID+ cohorts, respectively, adjusted for age, sex, region, nadir CD4, and HIV VL at entry. Result(s): Of 2,464 unvaccinated participants, 283 (11%) were COVID+;260 (92%) were asymptomatic. Median age was 53, 35% were women, 50% had nadir CD4 < 200, median current CD4 was 649, and 97% had HIV VL < 400. In the full cohort, COVID+ was associated with higher CMV PP65 IgG3 and FcgammaRIIA (P< 0.05);COVID severity was not associated with the non-SARS-CoV-2 repertoire. Among COVID-, older age, female sex, and lower nadir CD4 were associated with higher EBV and CMV responses;IgG1 levels were higher in women for all non-SARS-CoV-2 antigens assessed (P< 0.05). Among COVID+, higher BMI was associated with amplified SARS-CoV-2 IgG, IgA, IgM, and FcgammaRIIA responses (P< 0.05). Lower nadir CD4 was associated with a SARSCoV- 2 repertoire shift toward IgM and FcgammaRIIB (P< 0.05). Age and sex were not associated with SARS-CoV-2-related repertoire changes in COVID+. Conclusion(s): Our analysis presents a comprehensive view of host factors associated with the humoral immune repertoire among a global cohort of ART-treated PWH. COVID's association with higher CMV responses may suggest increased susceptibility to or a consequence of persistent inflammation after infection. The striking amplification of SARS-CoV-2 responses with higher BMI suggests an excessive inflammatory response. Lower nadir CD4 was related to uncontrolled extra-follicular and inhibitory SARS-CoV-2 responses, which are unlikely to be protective. These findings may suggest mechanisms underlying factors associated with worse COVID-19 outcomes among PWH. (Figure Presented).

Antibody Subclass Responses to SARS-CoV-2 in severe and nonsevere COVID-19 Patients

Background: SARS-CoV-2 is a highly contagious respiratory virus responsible for COVID-19 pandemic. To understand the role of antibodies in neutralization, our study quantified circulating levels of IgA/IgG and IgG subtypes induced at different days post onset of symptoms, in severe and non severe patients. Objective(s): To quantify circulating levels of IgA, IgG and IgG subclass in severe and non severe patients induced at different days post onset of symptoms. Material(s) and Method(s): Serum or plasma samples collected from 79 COVID-19 patients were used. Indirect SARS-CoV-2 specific IgA, IgG, and IgG subclass specific ELISAs were performed. Antibody titers between severe and non severe patients were compared at different times post onset of clinical symptoms. Titers in ELISA were correlated to neutralizing antibody titers. Results and Conclusion(s): Over 75% patients were positive for IgA and IgG antibodies in the first week. The ELISA titers did not differ during the first week of infection. However, patients with severe disease exhibited raised titers. Neutralizing antibody titers correlated with the ELISA titers in mild presentation but not in severe disease. IgA and IgG1 antibodies correlated stronger with neutralizing antibodies. The findings highlighted that IgA together with IgG play an important in SARS-CoV-2 neutralization.

Bimekizumab safety in patients with moderate-to-severe plaque psoriasis: Analysis of pooled data from up to three years of treatment in Phase 2 and 3 clinical trials

Background: Bimekizumab (BKZ) is a monoclonal IgG1 antibody used in the treatment of psoriasis which selectively inhibits interleukin (IL)-17F in addition to IL-17A.1,2 Data pooled over two years have indicated that BKZ is generally well-tolerated.3 We report three-year BKZ pooled safety data in patients with moderate-to-severe plaque psoriasis. Method(s): Safety data were evaluated for all patients who received one or more dose BKZ in four Phase 3 trials (BE SURE [NCT03412747], BE VIVID [NCT03370133], BE READY [NCT03410992], and their ongoing open-label extension BE BRIGHT open-label extension [NCT03598790;data cut-off : 10/23/2021]) and four Phase 2 trials (BE ABLE 1 [NCT02905006], BE ABLE 2 [NCT03010527], PS0016 [NCT03025542], PS0018 [NCT03230292]). Safety data were evaluated separately for patients receiving BKZ dosed 320mg every four weeks (Q4W) or every eight weeks (Q8W). Exposureadjusted incidence rates (EAIRs) for treatmentemergent adverse events (TEAEs) are the incidence of new cases per 100 patient-years (PY). Result(s): Total BKZ exposure was 4,245.3 PY (N=1,789) across Phase 2/3 trials, and 3,876.4 PY (N=1,495) in Phase 3 trials. TEAEs occurred at a rate of 186.1 across Phase 2/3 trials, serious TEAEs at 5.6, and TEAEs leading to discontinuation at 3.5. Eighteen deaths occurred (0.4/100 PY), all unrelated to study treatment except one (relationship unknown). TEAEs occurred less frequently in Q8W- than Q4W-treated patients in Phase 3 trials. Consistent with previous reports, most common TEAEs (EAIR) in Phase 2/3 trials were nasopharyngitis (15.3), oral candidiasis (10.2), and upper respiratory tract infection (7.1).3 EAIR of serious infections was 1.2. Most frequently reported were serious coronavirus infections (0.2). There were no cases of active tuberculosis. EAIR of oral candidiasis was 10.2, decreased vs two-year data (12.6),3 and was less common with BKZ Q8W vs Q4W. The vast majority of oral candidiasis events were mild or moderate (99.4%);none were serious. EAIRs of hepatic events (4.0) and elevated liver enzymes (3.4) were decreased vs. two-year data (4.3 and 3.6, respectively).3 EAIRs for inflammatory bowel disease (0.1), adjudicated major adverse cardiac events (0.6), and adjudicated suicidal ideation and behavior (0.1) were low. EAIRs for other safety topics of interest were also low and were similar to or lower than two-year EAIRs.3 Conclusion(s): BKZ was well-tolerated over three years. No safety signals were identified;EAIRs of TEAEs did not increase compared with data from two years.3.

ANTI-SARS-CoV-2 SPIKE RECEPTOR BINDING DOMAIN (S-RBD) IgG ANTIBODIES FOLLOWING CoronaVac ADMINISTRATION: A LONGITUDINAL STUDY. ANTI-SARS-CoV-2 S-RBD IgG ANTIBODIES

Reports on antibody titers following CoronaVac administration are still scarce, particularly when it comes to the post-vaccination effectiveness of CoronaVac in the Indonesian population. The purpose of this study is to determine the efficacy of COVID-19 vaccination by comparing the IgG levels against the S1 subunit of SARS-CoV-2 RBD after the first and second vaccinations. The researchers collected venous blood samples from participants after they received the CoronaVac 600 SU/0.5 mL vaccine at two different intervals (14 days and 28 days). Blood was drawn twice (after the first and second vaccinations) and tested for antibodies (positive antibody detection value of 50 AU/mL). Paired data were analyzed by using either the Wilcoxon test (numerical) or the McNemar test (categorical). The median IgG1 levels in the 14-day interval between vaccine doses were 64.40 AU/mL and IgG2 levels were 886.10 AU/mL. Meanwhile, the median IgG1 level was 146.10, and IgG2 level was 688.00.AU/mL in the group with a 28-day interval between vaccine doses. After the first vaccination, 60.00 % of study subjects had positive IgG levels, which increased to 98.57% after the second vaccination. Following the full-dose vaccination, all participants had higher antibody levels, and considered significant. The effect was stronger in the group that received the vaccine at 14-day intervals. CoronaVac has also been shown to increase the prevalence of detectable antibody positivity in study participants.Copyright © 2023 Russian Association of Allergologists and Clinical Immunologists, St. Petersburg Regional Branch (SPb RAACI). All rights reserved.

Viral enteritis in cattle: To well known viruses and beyond

Livestock products supply about 13 percent of energy and 28 percent of protein in diets consumed worldwide. Diarrhea is a leading cause of sickness and death of beef and dairy calves in their first month of life and also affecting adult cattle, resulting in large economic losses and a negative impact on animal welfare. Despite the usual multifactorial origin, viruses are generally involved, being among the most important causes of diarrhea. There are several viruses that have been confirmed as etiological agents (i.e., rotavirus and coronavirus), and some viruses that are not yet confirmed as etiological agents. This review summarizes the viruses that have been detected in the enteric tract of cattle and tries to deepen and gather knowledge about them.Copyright © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Preparation of the Monoclonal Antibody against the African Swine Fever Virus p54 Protein and Identification of the Antigenic Epitope.

The aim of this paper was to prepare specific monoclonal antibody (mAb) against African swine fever virus (ASFV) p54 protein. The p54 protein was expressed in Escherichia coli expression system and used as the antigen in mAb production. The spleen cells from the immunized BALB/c mice were fused with myeloma cells SP2/0. To screen the positive hybridoma cells, the purified p54 protein was used as envelope antigen for indirect ELISA. After four times' subcloning, the supernatant of hybridoma cells were used to identify mAb subtype, ascites were prepared via in vivo induction method in mice and then the mAb was purified. The titer of the mAb was detected by indirect ELISA, and the specificity of the mAb was identified by cross reactivity assay, IFA and Western blot. According to the predicted secondary structure of p54 protein, using the stepwise truncation method identified the epitope region of mAbs, and labeled the region in tertiary structure of p54 protein. Results were as follows: six hybridoma cells secreting p54 monoclonal antibody were successfully screened and named 28G12-1, 31G7-1, 31G7-2, 35F10-1, 35F10-2, 38D3-1, respectively. The heavy chains of 28G12-1, 31G7-1, and 31G7-2 were IgG2a type, the heavy chains of 35F10-1, 35F10-2, 38D3-1 were IgG1 type, light chains were all kappa chains. The lowest titer of mAb was 1:25 600, and having no cross reaction with PRRSV, PRV, PEDV, PPV, SADS-CoV, PCV2, the specificity was strong. All six monoclonal antibodies could recognize the 127-146 aa on carboxyl end. In this study, ASFV p54 protein and p54 monoclonal antibody were successfully obtained, and the epitopes of six mAbs were identified, these experimental data laid a foundation for the functional research of p54 protein and the study of ASFV epitope vaccine. Copyright © 2023 Editorial Board, Institute of Animal Science of the Chinese Academy of Agricultural Sciences. All rights reserved.

Prolonged fever and inflammation in a young child in the midst of the pandemic - it's not always MIS-C

Case Report: Prolonged fever in children is a symptom that is seen in many different diseases, infections, malignancies, and autoimmune conditions. This can, at times, make the correct diagnosis challenging. A previously healthy 10-year-old male was transferred to our institution with one week history of fever, fatigue, abdominal pain, and vomiting. Laboratory studies demonstrated pancytopenia, transaminitis, electrolyte abnormalities, elevated pro-inflammatory markers & D-Dimer, and hypoalbuminemia. COVID-19 IgG was reactive. Due to the severity in presentation the patient was transferred to the ICU with a presumptive diagnosis of MIS-C. Hewas started on IVIG as well as a five-day course of high-dose methylprednisolone per protocol. Aspirin was added, but later discontinued, due to worsening thrombocytopenia. CT imaging with contrast showed small bilateral pleural effusions & periportal edema, mild splenomegaly, and echocardiogram showed diffuse dilation of the left main and left anterior descending arteries. Given the laboratory findings the differential diagnosis was expanded, Ehrlichia caffeensis serology was sent and empiric Doxycycline started. EBV Nuclear Antigen IgG antibody and EBV Viral Capsid Antigen IgM Antibody resulted as positive suggesting recent or reactivated infection. Respiratory viral PCR with COVID-19, Cytomegalovirus and Parvovirus PCR were negative. Despite initial treatment, the patient continued to have persistent fever, severe pancytopenia, and high ferritin up to 24 426 ng/mL, raising suspicion for Haemophagocytic Lymphohistiocytosis (HLH). Soluble interleukin-2 level was elevated & his presentation was then considered to be more consistent with HLH given that he met 6/8 criteria. Screening for primary HLH including CD107a, perforin and granzyme B, SAP, and XIAP resulted in the latter three being normal but CD107a was abnormal. Next generation sequencing for primary criteria was negative. E. Chaffeensis resulted positive: IgM 1:80, IgG 1:256. MIS-C and HLH have overlapping features but differ in some clinical manifestations. Timely recognition and management is paramount as the management differs. This case illustrates the importance of performing a broad search for potential causes, allowing for appropriate and timely treatment. COVID-19 serology alone should not be the basis for diagnosis of MIS-C in a patient with fever and inflammation. This is important as SARS-CoV2 becomes endemic. Infections such as EBV and Ehrlichiosis should be on the differential particularly in endemic areas and during seasons of higher prevalence for the latter, as these have been well documented to cause HLH. Copyright © 2023 Southern Society for Clinical Investigation.

Caracterizacao Sorologica E Molecular Em Amostra De Paciente Com Ausencia De Dois Antigenos De Alta Frequencia De Diferentes Grupos Sanguineos

Objetivo: Relatar um caso imunohematologico complexo, descrevendo as estrategias sorologicas e moleculares realizadas para a caracterizacao fenotipica de um paciente com ausencia de dois antigenos de alta frequencia U (MNS:-5) e Yta (YT:-1), assim como, a determinacao do(s) anticorpo(s) de alta frequencia presente no soro. Materiais e metodos: Trata-se de um trabalho descritivo em que foram utilizados dados clinicos de prontuario disponiveis no laboratorio de referencia de imunohematologia (LRI) onde foram testadas as amostras. Resultados: Paciente de 84 anos, com anemia sintomatica, COVID-19 e abdomen agudo obstrutivo, teve a amostra encaminhada para o LRI para confirmacao de anticorpo anti-U no soro e genotipagem eritrocitaria. O soro do paciente foi testado com painel de hemacias comerciais e raras sendo reativo com todas as hemacias do painel em Gel-Liss/Enzima, exceto com hemacias S-s-U-/Yt(a+) demonstrando apenas a especificidade de anti-U. O teste de adsorcao alogenica com hemacias de doador tratadas com ZZAP excluiu a presenca de anticorpo anti-Yta no soro aloadsorvido. Para avaliar a importancia clinica do anticorpo, foi realizada a tecnica de MMA (Monocyte Monolayer Assay), sendo que o teste apresentou menos que 5% de atividade fagocitica dos Monocitos, alem disso, o fato da classe da Imunoglobulina nao pertencer a IgG1 ou IgG3 (cartao ID-Card DAT IgG1/IgG3, BioRad), indicaram que esse anticorpo nao possui importancia clinica. O DNA do paciente foi extraido do sangue total utilizando o Kit MagNa Pure, Roche. A genotipagem realizada pelas tecnicas do BloodChip Kit ID CoreXT - Grifol, PCR-SSP e PCR-RFLP demonstrou o seguinte resultado: GYPB*delecao;YT*2/2. O fenotipo foi confirmado como U- e Yt(a-) com antissoros provenientes do SCARF. Discussao: Antigenos de alta frequencia quando ausentes, resultam na dificuldade da busca de sangue compativel para a transfusao, assim como na disponibilidade de insumos e tecnicas bem padronizadas para a investigacao imunohematologica. Determinados antigenos de alta frequencia quando ausentes na membrana eritrocitaria podem afetar a expressao de antigenos de outros sistemas. Atraves de uma tecnica semi-automatizada de genotipagem identificamos que a amostra de um paciente tinha a ausencia de dois antigenos de alta frequencia U (MNS:-5) e Yta(YT:-1). Por se tratar de um caso complexo, estrategias sorologicas e moleculares foram realizadas para a caracterizacao fenotipica do paciente, determinacao do anticorpo de alta frequencia presente no soro e sua importancia clinica. Conclusao: A tecnica do BloodChip permitiu uma analise molecular mais completa, sendo possivel verificar a ausencia de dois antigenos de alta frequencia: U e Yta, o que tornou mais dificil a busca por doador fenotipo compativel para o paciente. Paineis de hemacias e soros raros foram capazes de definir a especificidade do anti-U e excluir a presenca do anti-Yta e de outros anticorpos que poderiam estar mascarados no soro. Apesar do anti-U nao aparentar importancia clinica, recomendamos a transfusao de concentrado de hemacias U- (MNS:-5), uma vez que esse anticorpo esta implicado em reacoes transfusionais hemoliticas. Copyright © 2022

Improved Mortality in COVID-19 Kidney Transplant Recipients Treated with Bamlanivimab

Purpose: Transplant recipients are particularly vulnerable to catastrophic sequelae of COVID-19. In an early multi-center study of 482 solid organ transplant (SOT) recipients with COVID-19, the authors reported a large percentage of hospitalizations (78%), mechanical ventilation (31%), and death (20.5%) during a 28 day window. Despite mortality reduction following the vaccine, COVID remains a mortality risk in this population. We sought to identify interventions to further mitigate the mortality risk. Bamlanivimab is a recombinant neutralizing human IgG1 monoclonal antibody (mAb) directed against the spike protein of SARS-Cov-2. We evaluated patient outcomes when early disease diagnosis was paired with mAb bamlanivimab therapy. Method(s): In a single center cohort of 147 kidney transplant recipients who tested positive for COVID during a 12 month period from March 2020 to March 2021, 41 eligible patients received IV bamlanivimab therapy. Eligible patients had symptoms <7 days and did not require supplemental oxygen at the time of bamlanivimab therapy. Patients in the exclusion group also included patients diagnosed with COVID before bamlanivimab was available. Result(s): Of 41 patients who received IV bamlanivimab therapy, zero deaths were observed and only four hospitalizations. Two patients required ventilatory support but were eventually successfully extubated. In contrast, of the 106 patients who did not receive bamlanivimab the mortality rate was 15 deaths (14%).In the total cohort of 147 kidney transplant patients, 68 patients required hospitalization (47%). Of these 68 patients, 21 patients were intubated (14%) and all 15 mortalities occurred in patients ineligible for bamlanivimab. Conclusion(s): Early detection of COVID-19 within 7 days of symptoms allowing for early intervention with mAb bamlanivimab therapy significantly reduced disease severity and mortality risk amongst kidney transplant recipients.

Anti-HLA Antibodies Do Not Increase in Kidney Transplant Recipients During COVID-19 Infection

Purpose: To determine if HLA allo-antibody levels are affected by COVID-19 in renal transplanted patients and to compare the immunoglobulin class and subclass profiles as well as the epitope binding patterns of anti-HLA and anti-SARS-CoV-2 antibodies. Method(s): A cross-sectional study of 46 kidney transplant recipients diagnosed with PCR+ SARS-CoV-2 infection was conducted. Serum samples were collected at the time of infection. For 21 patients, we obtained historical anti-HLA antibody information before COVID-19. Using a single-antigen bead Luminex assay, we determined IgG, IgG1/2/3/4, IgM, and IgA antibodies against Class I and Class II HLA, as well as against five SARS-CoV-2 (Wuhan strain) protein fragments: nucleocapsid, whole spike (S), spike S1, spike S2 and spike receptor binding domain (RBD). Result(s): 26/46 subjects had anti-HLA antibodies of which fourteen had donorspecific anti-HLA antibodies (DSA) compared with 45/46 had anti-SARS-CoV2 antibodies. The majority of DSA were specific to HLA-DQ (10/14), with a dominant IgG/IgG1/IgG3 subclass prevalence. Anti-SARS-CoV-2 antibodies exhibited stronger reactivity towards S and RBD and had increased IgM (38/43, 79%) and IgA (41/42, 85%) prevalence when compared to DSAs (5/14, 35% and 2/14, 14%, p<0.001).Out of 21 patients with pre-COVID-19 data available, calculated panel antibody reactivity (cPRA) levels did not change after COVID-19 in 14 cases (67%);cPRA increased in two cases (10%), both of them with allograft nephrectomy and immunosuppression discontinuation, and decreased in five patients (20%) (from 65.4+/-12.6% before COVID-19, to 29.4+/-33.6% after COVID-19) (Figure 1). Patients with DSA exhibited significantly lower anti-S IgG (9453+/-9945 vs 17975+/-12792;P=0.001), anti-RBD IgM (4464+/-3693 vs 8751+/-6468;P=0.03) and anti-nucleoprotein IgA (998+/-835 vs 5476+/-6895;P=0.001) anti-SARS-CoV2 antibody MFI values than patients without DSA. Conclusion(s): cPRA values did not increase following PCR confirmed COVID-19 diagnosis in renal transplant recipients and those subjects with pre-existing DSA had lower antibody strength directed at SARS-CoV-2 antigens. The lack of increase in alloantibody response is quite remarkable, since over 80% of the patients underwent either significant reduction or withdrawal of mycophenolate mofetil after COVID-19 diagnosis. (Figure Presented).

PURIFICATION OF ANTI-RBD ANTIBODIES OBTAINED FROM LLAMA (Lama glama) FOR POTENTIAL COVID-19 THERAPY

Despite worldwide efforts to develop different treatments for SARS-CoV-2 COVID-19, the situation remains critical, requiring rapid and effective strategies. In this regard, antibodies (Ab) have demonstrated clinical potential. Among them, camelid nanoAb (VHH) arise as a possible alternative, as they recognize epitopes which are inaccessible to conventional Ab. Further advantages of VHH are their small size, high solubility, high stability, and resistance to low pH. The aim of this work is to describe a purification scheme of different isotypes of anti-SARS-CoV-2 immunoglobulin G (IgG) produced after immunizing two llamas (Lama glama). To achieve this, plasma was injected into an affinity chromatographic column (Protein G), and the resulting fractions were analyzed by SDS-PAGE under non-reducing conditions. The anti-RBD titers were determined by an “in house” ELISA, reaching titers of 52000 and 13000 for IgG1 and IgG3 fractions, respectively. Subsequently, an affinity column (HiTrap NHS-activated) was prepared to separate monospecific anti-RBD polyclonal Ab. RBD produced in our laboratory was covalently coupled to this column, achieving a coupling efficiency of 97%. Different isotypes of monospecific anti-RBD Ab (IgG1: 140 kDa and IgG3: 95 kDa) were obtained. IgG3 represent the starting point for obtaining VHH and/or evaluating their potential use as a therapeutic or preventive alternative, which represents a notable regional contribution in the fight against COVID-19.

SARS-CoV-2-NEUTRALISING MONOCLONAL ANTIBODIES: MECHANISM OF ACTION AND RESEARCH RESULTS

The COVID-19 vaccination has become a way of effective prevention of the decease for most people globally. However, there is a cohort of patients who are not able to form a full-fledged immune response due to primary or secondary immunodeficiency conditions caused by genetic disorders, severe course of chronic diseases, due to their age or the use of drugs that suppress the immune response. The use of monoclonal viral antibodies for immunocompromised patients is the most efficient method of pre- and post-contact and even long-term prevention, as well as the treatment of coronavirus infection. Monoclonal antibodies are obtained from B-lymphocytes of patients recovered from COVID-19. As a result of further modification aimed at increasing of the efficiency and reducing the risk of unwanted phenomena in the use, the virus-neutralizing recombinant monoclonal antibodies of the IgG1 class were designed to implement preventive and therapeutic schemes for COVID-19. Treatment of a new coronavirus infection with drugs with direct etiotropic action is most effective when prescribing in the early stages of the disease, which is especially relevant in patients at risk for a severe/critical clinical course of the disease and can be performed as outpatient clinical procedures. The article analyzes the results of clinical studies of efficacy and safety of mono- and combined drugs of monoclonal antibodies to SARS-CoV-2 in patients with the new coronavirus infection, as well as potential possibilities for their use for the treatment of COVID-19 caused by the new SARS-CoV-2 strains with multiple mutations on the example of the Omicron strain.

COMPARISON OF THE HUMORAL AND CELLULAR IMMUNITY IN COVID-19 CONVALESCENTS

The SARS-CoV-2 virus caused the COVID-19 pandemic is related to the SARS-CoV-1 and MERS coronaviruses, which were resulted in 2003 and 2012 epidemics. Antibodies in patients with COVID-19 emerge 7–14 days after the onset of symptoms and gradually increase. Because the COVID-19 pandemic is still in progress, it is hard to say how long the immunological memory to the SARS-CoV-2 virus may be retained. The aim of this study was to study a ratio between humoral and cellular immunity against the SARS-CoV-2 S protein in COVID-19 convalescents. There were enrolled 60 adults with mild to moderate COVID-19 2 to 12 months prior to the examination. The control group consisted of 15 adults without COVID-19 or unvaccinated. Specific antibodies to the SARS-CoV-2 virus were determined by ELISA with the SARS-CoV-2-IgG-ELISA-BEST kit. To determine the specific IgG and IgA subclasses, the anti-IgG conjugate from the kit was replaced with a conjugate against the IgG subclasses and IgA. Additional incubation with or without denaturing urea solution was used to determine the avidity of antibodies. Peripheral blood mononuclear cells were isolated by gradient centrifugation, incubated with or without coronavirus S antigen for 20 hours, stained by fluorescently labeled antibodies, and the percentage of CD8highCD107a cells was assessed on flow cytometer BD FACSCanto II. In the control group, neither humoral nor cellular immunity against the SARS-CoV-2 S protein was found. In the group of convalescents, the level of IgG antibodies against the SARS-CoV-2 S protein varies greatly not being strictly associated with the disease duration, with 57% and 43% of COVID-19 patients having high vs. low level of humoral response, respectively. A correlation between level of specific IgG and IgA was r = 0.43. The avidity of antibodies increased over time in convalescents comprising 49.9% at 6–12 months afterwards. No virus-specific IgG2 and IgG4 subclasses were detected, and the percentage of IgG1 increased over time comprising 100% 6–12 months after recovery. 50% of the subjects examined had high cellular immunity, no correlations with the level of humoral immunity were found. We identified 4 combinations of humoral and cellular immunity against the SARS-CoV-2 S protein: high humoral and cellular, low humoral and cellular, high humoral and low cellular, and vice versa, low humoral and high cellular immunity.

American Society for Clinical Pharmacology and Therapeutics - 123rd Annual Meeting. Virtual - March 16-18, 2022

The 2022 American Society for Clinical Pharmacology and Therapeutics (ASCPT) Annual Meeting held virtually, with "Disruptive innovation" as the motto, offered attendees an outstanding scientific program focused on clinical pharmacology, translational medicine, drug discovery and drug development. It is the most important event for scientists involved in clinical pharmacology and translational medicine. The ASCPT conference offers scientists from different professional scopes and around the world the perfect opportunity to discuss emerging science. It focuses on improving the understanding and use of existing drug therapies and developing safer and more effective treatments for the future. Oral and poster presentations were available for participants during the running of the conference to accommodate the different time zones. Presentations covered the latest research with the option to ask questions after each presentation via a chat function. Discussion boards were available to provide networking opportunities for virtual attendees.

Antigenic target, antibody subclass, function and glycans and SARS-CoV-2 coinfection impact the placental transfer of herpes simplex virus antibodies

Primary versus recurrent herpes simplex virus 1 or 2 (HSV-1 or HSV- 2) infection during pregnancy carries a higher risk of neonatal herpes suggesting that placental transfer of antibodies protects against transmission and infection. Murine and clinical studies demonstrate that antibody-dependent cellular cytotoxicity (ADCC) provides greater protection than neutralizing antibodies (nAbs) against disseminated neonatal disease. To quantify the relative transfer of HSV-specific Abs with different functions and targets and whether SARS-CoV-2 coinfection modified transfer, we conducted a prospective cohort study of mother-infant dyads prior to and during COVID-19. Total and HSV lysate, glycoprotein D (gD) and glycoprotein B (gB)- specific IgG, IgG1 and IgG3, nAbs, and ADCC were quantified in paired 3rd trimester maternal and cord blood. Transfer ratios (TR) were defined as cord: maternal Ab levels. IgG1 and IgG3 subclass and gD or gB-specific Abs were isolated by column purification and glycan profiles were assessed using mass spectrometry. The pre-COVID study population included 21 term and 15 preterm dyads who were HSV-1 (± HSV-2) seropositive (+) enrolled between 2018-2019 and the peri- COVID cohort included 25 HSV-1 (±HSV-2)+term dyadswhosemothers were also SARS-CoV-2 PCR and COVID Ab+ at delivery;14 were asymptomatic and 11 had mild-moderate COVID disease. None of the mothers had active genital HSV lesions during delivery. HSV-specific IgG, IgG1, and IgG3 TR were higher in term compared to preterm pre-COVID dyads (all p< 0.05). Similarly, the neutralizing Ab TR was 2.4[1.5, 4.0] in term vs 0.8[0.6, 1] in preterm (median [95%CI], p< 0.0001) but the ADCC TR was < 1.0 for both groups. To determine if the low ADCC TR reflected antigenic target, subclass, and/or glycans, we enriched for anti-gD and anti-gB specific and IgG1 and IgG3 Abs. These envelope glycoproteins are primary targets of neutralizing and ADCC responses, respectively. The anti-gD Abs were exclusively IgG1 and had only neutralizing activity. In contrast, anti-gB Abs were both IgG1 and IgG3;the IgG1 gB Abs had both neutralizing and ADCC activity whereas the IgG3 were only neutralizing. The anti-gD Abs were enriched for glycans associated with an affinity for FcRn, whereas anti-gB Abs expressed glycans associated with both FcRn and FcγRIIIa (receptor-associated with ADCC activity) binding. There was no significant difference in HSV-specific IgG TR in pre-COVID vs COVID dyads (0.42) but the nAb TR was lower (p = 0.018) and ADCC TR higher (p<0.001) in COVID compared to pre-COVID patients. Studies are in progress to assess whether this reflects increased placental colocalization of FcRn and FcgRIIIA, which would favor the transfer of ADCCAbs or modified Fc glycans. ADCC Abs transfer relatively inefficiently compared to nAbs, particularly in preterm infants and this may contribute to an increased risk of HSV disease. ADCC Ab transfer increased with SARS-CoV-2 coinfection, which may reflect differences in glycans and/or alterations in the placental architecture. Defining the determinants of ADCC transfer has implications for future vaccine and monoclonal Ab strategies to prevent/treat neonatal herpes. We speculate that increasing the transfer of ADCC may be a key element in providing immune protection.

The impact of different pathogen reduction technologies on total IgG and subclass profiles of COVID-19 convalescent plasma

Background: COVID-19 convalescent plasma (CCP) was shown to reduce disease progression if high-titre CCP is administered in early infection. CCP donors have a risk profile like first time donors, especially with respect to window-period viral transmissions. Pathogen reduction (PR) could mitigate that risk, but may have impact on quality and quantity of plasma proteins, including neutralizing antibodies. It has been shown that different IgG subclasses contribute differently to CCP neutralizing activity, raising the question of a potential impact of PR on different IgG subclasses. Aims: Side-by-side comparison of the impact of 3 commercially available PR technologies on total IgG and subclasses quantity and subclass distribution in CCP. Methods: 36 apheresis CCP donations collected with a MCS+ 9000 plasmapheresis device (Haemonetics S.A., Switzerland), or DigiPla 80 (Sichuan Nigale Biomed, China) plasmapheresis device (650-750 ml) were allocated to 3 study groups with 12 units respectively. The impact of amotosalen/UVA (AS)-treatment (INTERCEPT Blood System, Cerus) against Riboflavin UVB (RB) (Mirasol Pathogen Reduction System, Terumo BCT), AS against Methylene Blue (MB) (Theraflex MB, Macopharma) and RB against MB on the quantity and distribution of IgG and subclasses was assessed in a side-by-side comparison study with a nephelometric analyser (BN II System, Siemens Healthcare). PRtreatment was conducted immediately post collection. All samples for analysis were frozen within 6 h post collection and stored at -75°C until testing. All samples were analysed simultaneously with the same device, the same lot of reagents and the same operator. Results: IgG subclass distributions were not significantly changed post PR-treatment with all 3 technologies (p > 0.05). There was also no significant difference in the median loss of concentration for IgG1 and IgG2 between the three technologies (p > 0.05). The median loss (%) of IgG3 (2.1 and 2.6-fold compared to AS and MBtreatment respectively, p < 0.01) and IgG4 (1.6 and 5.9-fold compared to AS and MB-treatment respectively, p < 0.01) post RBtreatment was significantly higher. The median loss (%) of IgG4 post AS-treatment was significantly higher compared to MB-treatment (3.5-fold, p < 0.01). Summary/Conclusions: The 3 commercially available PR systems do not significantly change the IgG subclass distribution, but impact differently IgG3 and IgG4 post-treatment loss. It was reported that IgG1 and IgG3 play an important role in neutralization, which should be considered when planning PR-treatment for CCP. .

The spectrum of ABO hemolytic disease of the fetus and newborn in neonates born to Group O mothers

Background: ABO hemolytic disease of the fetus and newborn (ABOHFDN) is a frequent event, and usually a problem of the neonate rather than the fetus, however, it is difficult to predict the disease severity. Thus, there is a need to increase awareness towards ABOHFDN for optimizing care in terms of early diagnosis and adequate monitoring. Aims: To determine the frequency of ABO-incompatibility in neonates born to group O mothers and to assess the severity of ABO-HDFN in neonates and determine the neonatal outcomes. Methods: This prospective observational study was carried out from February 2020 to May 2021 after obtaining a written informed consent from the mothers. A total of 260 neonates born to blood group O mothers were recruited. The maternal red cell antibody screen (ABS) using a 3-cell panel (Diacell, Bio-Rad, Switzerland) and the neonatal direct antiglobulin test (DAT) were done by column agglutination technique (CAT). For DAT positive samples, the IgG subclass of anti-A/anti-B was determined using DAT IgG1/IgG3 screening cards (Bio-Rad, Switzerland) and a heat elution at 56°C was also performed. The maternal anti-A/anti-B IgG titers was determined by tube technique after treating the serum sample with 0.01 M di-thiothreitol (DTT). The neonatal total serum bilirubin (TSB) and other relevant parameters were also recorded. The requirement for treatment in terms of phototherapy and/or exchange transfusion (ET) and the neonatal outcome were also recorded. Due to travel restrictions during the ongoing COVID-19 pandemic, the follow-up was performed telephonically with parents 6-8 weeks after discharge. Results: Of the 260 group O mothers, none had positive ABS. Of the 260 neonates born to them as an outcome of singleton pregnancies, 84 with blood group O were excluded from the study. The overall frequency of ABO-incompatibility between mother and neonates was 67.69% (176/260). Out of 176 neonates, 77 (43.8%) were group A and 99 (56.2%) were group B, and 15 (8.5%) of them had a positive DAT. Overall, 26.7% (47/176) neonates received phototherapy and 172 (97.7%) neonates survived. The mean (±SD) duration of phototherapy (hours) was 34.17 (±25.67) hours and it ranged from 12- 120 h. Only 1 neonate required ET. None of the neonates required readmission. The median maternal IgG anti-A titre was 16 (8-64) (range: 2-512), while the IgG anti-B titre was 32 (32-64) (range: 4- 512) (p = <0.001). The maximal TSB in neonates had a significant positive association with neonatal birth weight (p = 0.045), maturity at birth (p = 0.037), positive DAT (p = 0.006) and requirement of phototherapy (p = <0.001). Neonatal DAT positivity was significantly associated with maternal IgG titers (p = <0.001), neonatal PCV (p = 0.017), maximal TSB (p = 0.006), requirement (p = <0.001) and duration of phototherapy (p = 0.024). At a cut-off of maternal IgG titre ≥64, it predicted the requirement of phototherapy with a sensitivity of 72.3% and a specificity of 72%. The relative risk (95% CI) of a DAT positive neonate requiring phototherapy was calculated to be 4.55 (3.12-6.33). Summary/Conclusions: The frequency of ABO-incompatibility in neonates born to group O mothers was 67.69% (176/260). The maternal IgG titre of anti-A/anti-B of 64 or more could be a good predictor for identifying the neonates at-risk for developing hyperbilirubinemia requiring further management and combining it with neonatal DAT further enhances the sensitivity to identify such at-risk neonates.

SARS-CoV-2 PLASMA VIREMIA and DYSREGULATED IMMUNITY in SEVERE COVID-19

Background: Critical COVID-19 occurs ca. 7d from symptoms onset, and is associated to immune dysregulation as well as SARS-CoV-2 detection in plasma (i.e. viremia). We hereby sought to detail the association between SARS-CoV-2 viremia measured at the end of the first week of disease and immune phenotypes/function in COVID-19 patients. Methods: We consecutively enrolled patients hospitalized in the acute phase of ascertained SARS-CoV-2 pneumonia. In this disease stage, we studied SARS-CoV-2 viremia (RT-PCR) and cytokines (MACSPlex), HLA-DR+CD38+ activated, GRZB+PRF+ pro-cytolitic T-cells, intracellular cytokine production (IL-2, IFNγ, TNFα, IL-4, IL-17A) after SARS-CoV-2 challenge (S-N-M-peptide pool). Simultaneous Th1-cytokines production (polyfunctionality) and amount (iMFI) was assessed. Humoral response: anti-S1/S2 IgG, anti-RBD total-Ig, IgM, IgA, IgG1 and IgG3 (ELISA), pseudoviruses neutralization (ID50) and Fc-mediated functions (%ADCC). Results: Out of 54 patients, 27 had detectable viremia (V+). Albeit comparable age and co-morbidities, V+ patients more frequently required non-invasive/invasive ventilatory support (p=0.035), with a trend to higher death (p=0.099) vs patients with undetectable viremia (V-)(Fig.1A). V+ displayed higher circulating IFN-α (p=0.002) and IL-6 (0.003), lower activated HLA-DR+CD38+CD4 (p=0.01) and CD8 (p=0.02), with no differences in GRZB+PRF+ T-cells. V+ featured reduced SARS-CoV-2-specific cytokine-producing T-cells, reaching significance for IFNγ+CD4 (p=0.02), TNFα+CD8, IL-4+CD8 (p=0.04) (Fig.1B-C), with lower bi-and tri-functional SARS-CoV-2-specific CD4 Th1, reaching significance for IL-2+TNFα+CD4 (p=0.03) (Fig.1D). A trend towards lower cytokines iMFI in bi-and tri-functional SARS-CoV-2-specific CD4 Th1 was observed in V+, reaching significance for IL-2+TNFα+CD4, p=0.004. V+ displayed lower anti-S IgG, anti-RBD total-Ig, IgM, IgG1 and IgG3 (Fig.1E), with lower ID50 and %ADCC vs V-(Fig.1F-G). Conclusion: Hospitalized COVID-19 patients with detectable plasma SARS-CoV-2 RNA in the acute phase of disease present worse outcome, higher inflammatory cytokines, fewer activated and SARS-CoV-2-specific polyfunctional T-cells, suggesting a link between SARS-CoV-2 viremia at the end of the first stage of disease and immune dysregulation. Whether high ab initium viral burden and/or intrinsic host factors contribute to a delayed and/or exhausted immune response in severe COVID-19 remains to be elucidated, to further inform strategies of targeted therapeutic interventions.