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Asian Pacific Journal of Allergy and... Dec 2022The data on the immunogenicity and efficacy of heterologous primary series COVID-19 vaccination are still limited. (Meta-Analysis)
Meta-Analysis
Binding and neutralizing antibody levels and vaccine efficacy/effectiveness compared between heterologous and homologous primary series COVID-19 vaccination: A systematic review and meta-analysis.
BACKGROUND
The data on the immunogenicity and efficacy of heterologous primary series COVID-19 vaccination are still limited.
OBJECTIVE
To investigate the immunogenicity and vaccine efficacy/effectiveness compared between heterologous and homologous primary series COVID-19 vaccination.
METHODS
We conducted a multi-source search for randomized controlled trials, prospective cohort, and case-control studies that investigated the immunogenicity or vaccine efficacy/effectiveness (VE) of heterologous primary series vaccination. Six online databases were searched from inception to June 2022. The primary outcome was the levels of binding antibodies and neutralizing antibodies (NAbs), and the secondary outcomes were VE against COVID-19 infection, hospitalization, and death.
RESULTS
Among the 28 included studies, 21 and 7 were included to investigate immunogenicity and VE outcome, respectively. Heterologous CoronaVac (CV)/ChAdOx1 (ChAd) induced higher anti-RBD IgG and NAbs against wild type and delta variants compared to homologous CV or ChAd. However, risk of documented infection of CV/ChAd was similar to homologous CV, but higher than homologous ChAd (odds ratio: 2.56, 95% CI: 1.02-6.37). Heterologous ChAd/BNT162b2 (BNT) elicited a higher anti-spike level than homologous ChAd or BNT, and induced a higher NAbs level against delta variants compared to homologous ChAd. The VE of ChAd/BNT and homologous ChAd or BNT against hospitalization were similar.
CONCLUSIONS
Heterologous CV/ChAd induced higher binding and neutralizing antibody levels than homologous CV or ChAd; and, ChAd/BNT induced higher binding and neutralizing antibody levels than homologous ChAd. However, CV/ChAd demonstrated increased risk of infection compared to homologous ChAd. Therefore, immunogenicity findings and real-world vaccine efficacy/effectiveness should be integrated in clinical practice.
Topics: Humans; Antibodies, Neutralizing; Vaccine Efficacy; COVID-19 Vaccines; BNT162 Vaccine; Prospective Studies; COVID-19; SARS-CoV-2; Vaccination; Antibodies, Viral
PubMed: 36681658
DOI: 10.12932/AP-121122-1501 -
Frontiers in Immunology 2022The diversity of three hypervariable loops in antibody heavy chain and light chain, termed the complementarity-determining regions (CDRs), defines antibody's binding...
The diversity of three hypervariable loops in antibody heavy chain and light chain, termed the complementarity-determining regions (CDRs), defines antibody's binding affinity and specificity owing to the direct contact between the CDRs and antigens. These CDR regions typically contain tyrosine (Tyr) residues that are known to engage in both nonpolar and pi stacking interaction with antigens through their complementary aromatic ring side chains. Nearly two decades ago, sulfotyrosine residue (sTyr), a negatively charged Tyr formed by Golgi-localized membrane-bound tyrosylprotein sulfotransferases during protein trafficking, were also found in the CDR regions and shown to play an important role in modulating antibody-antigen interaction. This breakthrough finding demonstrated that antibody repertoire could be further diversified through post-translational modifications, in addition to the conventional genetic recombination. This review article summarizes the current advances in the understanding of the Tyr-sulfation modification mechanism and its application in potentiating protein-protein interaction for antibody engineering and production. Challenges and opportunities are also discussed.
Topics: Complementarity Determining Regions; Immunoglobulin Heavy Chains; Antigens; Golgi Apparatus; Tyrosine
PubMed: 36569848
DOI: 10.3389/fimmu.2022.1072702 -
Frontiers in Immunology 2022CD47-SIRPα interaction acts as a "don't eat me" signal and is exploited by cancer to downregulate innate and adaptive immune surveillance. There has been intense... (Meta-Analysis)
Meta-Analysis
CD47-SIRPα interaction acts as a "don't eat me" signal and is exploited by cancer to downregulate innate and adaptive immune surveillance. There has been intense interest to develop a mechanism of blockade, and we aimed to analyze the emerging data from early clinical trials. We performed a systematic review and meta-analysis of relevant databases and conference abstracts including clinical trials using CD47 and/or SIRPα inhibitors in cancer treatment. Nonlinear mixed models were applied for comparison of response and toxicity. We retrieved 317 articles, 24 of which were eligible. These included 771 response-evaluable patients with hematologic (47.1%) and solid tumors (52.9%). Of these, 6.4% experienced complete response, 10.4% partial response, and 26.1% stable disease for a 16.7% objective response rate (ORR), 42.8% disease control rate, and 4.8-month median duration of response. ORR was significantly higher for hematologic cancers (25.3%) than solid cancers (9.1%, p=0.042). Comparing by mechanism, seven CD47 monoclonal antibodies (mAbs) and six selective SIRPα blockers were given alone or combined with checkpoint inhibitors, targeted therapy, and/or chemotherapy. In solid cancers, selective SIRPα blockade showed a higher ORR (16.2%) than anti-CD47 mAbs (2.8%, p=0.079), which was significant for combination therapies (ORR 28.3% vs 3.0%, respectively, p=0.010). Responses were seen in head and neck, colorectal, endometrial, ovarian, hepatocellular, non-small cell lung, and HER2+gastroesophageal cancers. Dose-limiting toxicity (DLT) was seen in 3.3% of patients (5.4% anti-CD47 mAbs, 1.4% selective SIRPα blockers; p=0.01). The frequency of treatment-related adverse events (TRAEs) ≥grade 3 was 18.0%, similar between the two groups (p=0.082), and mostly laboratory abnormalities. For anti-CD47 mAbs, the most common toxicities included grade 1-2 fatigue (27.2%), headache (21.0%), and anemia (20.5%). For selective SIRPα blockers, these included grade 1-2 infusion reaction (23.1%) and fatigue (15.8%). Anti-CD47 mAbs were significantly more likely than selective SIRPα blockers to cause grade 1-2 fever, chills, nausea/vomiting, headache, and anemia. In conclusion, combination therapies using selective SIRPα blockade had higher response rates in solid tumors than anti-CD47 mAb combinations. Hematologic changes were the main TRAEs, and selective SIRPα blockers seemed to have a better grade 1-2 toxicity profile. Treatment was well-tolerated with minimal DLTs.
Topics: Humans; Protein Binding; Antibodies, Monoclonal; Fatigue; Headache; Neoplasms; CD47 Antigen
PubMed: 36439116
DOI: 10.3389/fimmu.2022.1027235 -
Frontiers in Immunology 2022Chimeric antigen receptor (CAR)-based therapies are presented as innovative treatments for multiple malignancies. Despite their clinical success, there is scientific...
Chimeric antigen receptor (CAR)-based therapies are presented as innovative treatments for multiple malignancies. Despite their clinical success, there is scientific evidence of the limitations of these therapies mainly due to immunogenicity issues, toxicities associated with the infusion of the product, and relapses of the tumor. As a result, novel approaches are appearing aiming to solve and/or mitigate the harmful effects of CAR-T therapies. These include strategies based on the use of ligands as binding moieties or ligand-based CAR-T cells. Several proposals are currently under development, with some undergoing clinical trials to assess their potential benefits. In addition to these, therapies such as chimeric autoantibody receptor (CAAR), B-cell receptor antigen for reverse targeting (BAR), and even chimeric human leukocyte antigen (HLA) antibody receptor (CHAR) have emerged, benefiting from the advantages of antigenic ligands as antibody-binding motifs. This review focuses on the potential role that ligands can play in current and future antitumor treatments and in other types of diseases, such as autoimmune diseases or problems associated with transplantation.
Topics: Humans; Ligands; Neoplasms; Receptors, Antigen, B-Cell; Receptors, Antigen, T-Cell; Receptors, Chimeric Antigen; T-Lymphocytes
PubMed: 36172370
DOI: 10.3389/fimmu.2022.932559 -
Frontiers in Immunology 2022We systematically reviewed and summarized studies focusing on Bharat Biotech's Whole Virion Inactivated Corona Virus Antigen BBV152 (Covaxin), which is India's...
We systematically reviewed and summarized studies focusing on Bharat Biotech's Whole Virion Inactivated Corona Virus Antigen BBV152 (Covaxin), which is India's indigenous response to fighting the SARS-CoV-2 pandemic. Studies were searched for data on the efficacy, immunogenicity, and safety profile of BBV152. All relevant studies published up to March 22, 2022, were screened from major databases, and 25 studies were eventually inducted into the systematic review. The studies focused on the virus antigen (6 μg) adjuvanted with aluminium hydroxide gel and/or Imidazo quinolin gallamide (IMDG), aTLR7/8 agonist. Pre-clinical, phase I, and II clinical trials showed appreciable immunogenicity. Both neutralizing and binding antibody titers were significant and T cell responses were Th1-biased. Phase III trials on the 6 μg +Algel-IMDG formulation showed a 93.4% efficacy against severe COVID-19. Data from the trials revealed an acceptable safety profile with mostly mild-moderate local and systemic adverse events. No serious adverse events or fatalities were seen, and most studies reported milder and lesser adverse events with Covaxin when compared with other vaccines, especially Oxford-Astra Zeneca's AZD1222 (Covishield). The immunogenicity performance of Covaxin, which provided significant protection only after the second dose, was mediocre and it was consistently surpassed by Covishield. One study reported adjusted effectiveness against symptomatic infection to be just 50% at 2 weeks after the second dose. Nonetheless, appreciable results were seen in previously infected individuals administered both doses. There was some evidence of coverage against the Alpha, Beta, and Delta variants. However, neither Covaxin nor Covishield showed sufficient protection against the Omicron variant. Two studies reported super-additive results on mixing Covaxin with Covishield. Further exploration of heterologous prime-boost vaccination with a combination of an inactivated vaccine and an adenoviral vector-based vaccine for tackling future variants may be beneficial.
Topics: COVID-19; COVID-19 Vaccines; ChAdOx1 nCoV-19; Humans; SARS-CoV-2; Vaccines, Inactivated; Viral Vaccines
PubMed: 36016940
DOI: 10.3389/fimmu.2022.863162 -
The Cochrane Database of Systematic... Aug 2022High efficacy in terms of protection from severe COVID-19 has been demonstrated for several SARS-CoV-2 vaccines. However, patients with compromised immune status develop... (Review)
Review
BACKGROUND
High efficacy in terms of protection from severe COVID-19 has been demonstrated for several SARS-CoV-2 vaccines. However, patients with compromised immune status develop a weaker and less stable immune response to vaccination. Strong immune response may not always translate into clinical benefit, therefore it is important to synthesise evidence on modified schemes and types of vaccination in these population subgroups for guiding health decisions. As the literature on COVID-19 vaccines continues to expand, we aimed to scope the literature on multiple subgroups to subsequently decide on the most relevant research questions to be answered by systematic reviews.
OBJECTIVES
To provide an overview of the availability of existing literature on immune response and long-term clinical outcomes after COVID-19 vaccination, and to map this evidence according to the examined populations, specific vaccines, immunity parameters, and their way of determining relevant long-term outcomes and the availability of mapping between immune reactivity and relevant outcomes.
SEARCH METHODS
We searched the Cochrane COVID-19 Study Register, the Web of Science Core Collection, and the World Health Organization COVID-19 Global literature on coronavirus disease on 6 December 2021. SELECTION CRITERIA: We included studies that published results on immunity outcomes after vaccination with BNT162b2, mRNA-1273, AZD1222, Ad26.COV2.S, Sputnik V or Sputnik Light, BBIBP-CorV, or CoronaVac on predefined vulnerable subgroups such as people with malignancies, transplant recipients, people undergoing renal replacement therapy, and people with immune disorders, as well as pregnant and breastfeeding women, and children. We included studies if they had at least 100 participants (not considering healthy control groups); we excluded case studies and case series.
DATA COLLECTION AND ANALYSIS
We extracted data independently and in duplicate onto an online data extraction form. Data were represented as tables and as online maps to show the frequency of studies for each item. We mapped the data according to study design, country of participant origin, patient comorbidity subgroup, intervention, outcome domains (clinical, safety, immunogenicity), and outcomes. MAIN RESULTS: Out of 25,452 identified records, 318 studies with a total of more than 5 million participants met our eligibility criteria and were included in the review. Participants were recruited mainly from high-income countries between January 2020 and 31 October 2021 (282/318); the majority of studies included adult participants (297/318). Haematological malignancies were the most commonly examined comorbidity group (N = 54), followed by solid tumours (N = 47), dialysis (N = 48), kidney transplant (N = 43), and rheumatic diseases (N = 28, 17, and 15 for mixed diseases, multiple sclerosis, and inflammatory bowel disease, respectively). Thirty-one studies included pregnant or breastfeeding women. The most commonly administered vaccine was BNT162b2 (N = 283), followed by mRNA-1273 (N = 153), AZD1222 (N = 66), Ad26.COV2.S (N = 42), BBIBP-CorV (N = 15), CoronaVac (N = 14), and Sputnik V (N = 5; no studies were identified for Sputnik Light). Most studies reported outcomes after regular vaccination scheme. The majority of studies focused on immunogenicity outcomes, especially seroconversion based on binding antibody measurements and immunoglobulin G (IgG) titres (N = 179 and 175, respectively). Adverse events and serious adverse events were reported in 126 and 54 studies, whilst SARS-CoV-2 infection irrespective of severity was reported in 80 studies. Mortality due to SARS-CoV-2 infection was reported in 36 studies. Please refer to our evidence gap maps for more detailed information.
AUTHORS' CONCLUSIONS
Up to 6 December 2021, the majority of studies examined data on mRNA vaccines administered as standard vaccination schemes (two doses approximately four to eight weeks apart) that report on immunogenicity parameters or adverse events. Clinical outcomes were less commonly reported, and if so, were often reported as a secondary outcome observed in seroconversion or immunoglobulin titre studies. As informed by this scoping review, two effectiveness reviews (on haematological malignancies and kidney transplant recipients) are currently being conducted.
Topics: Ad26COVS1; Adult; BNT162 Vaccine; COVID-19; COVID-19 Vaccines; ChAdOx1 nCoV-19; Child; Female; Hematologic Neoplasms; Humans; Pregnancy; SARS-CoV-2; Vaccination; Vaccines
PubMed: 35943061
DOI: 10.1002/14651858.CD015021 -
Nephrology, Dialysis, Transplantation :... Jul 2022In the general population, the seroconversion rate after primary vaccination with two doses of an anti-severe acute respiratory syndrome coronavirus 2 messenger RNA... (Meta-Analysis)
Meta-Analysis
BACKGROUND
In the general population, the seroconversion rate after primary vaccination with two doses of an anti-severe acute respiratory syndrome coronavirus 2 messenger RNA (mRNA) vaccine reaches nearly 100%, with significantly higher antibody titers after mRNA-1273 vaccination compared to BNT162b2 vaccination. Here we performed a systematic review and meta-analysis to compare the antibody response after two-dose mRNA-1273 versus BNT162b2 vaccination in solid organ transplant (SOT) recipients.
METHODS
A systematic literature review was performed using PubMed, Web of Science and the Cochrane Library and original research papers were included for a meta-analysis to calculate vaccine-specific seroconversion rates for each of the mRNA vaccines. Next, the pooled relative seroconversion rate was estimated.
RESULTS
Eight studies that described the development of antibodies against receptor-binding domain (RBD) and/or spike protein were eligible for meta-analysis. Two of these studies also reported antibody titers. The meta-analysis revealed lower seroconversion rates in SOT recipients vaccinated with two doses of BNT162b2 {44.3% [95% confidence interval (CI) 34.1-54.7]} as compared with patients vaccinated with two doses of mRNA-1273 [58.4% (95% CI 47.2-69.2)]. The relative seroconversion rate was 0.795 (95% CI 0.732-0.864).
CONCLUSIONS
This systematic review and meta-analysis indicates that in SOT recipients, higher seroconversion rates were observed after vaccination with mRNA-1273 compared with BNT162b2.
Topics: 2019-nCoV Vaccine mRNA-1273; Antibodies, Viral; BNT162 Vaccine; COVID-19; Humans; Organ Transplantation; RNA, Messenger; Seroconversion; Transplant Recipients; Vaccination; Vaccines
PubMed: 35544087
DOI: 10.1093/ndt/gfac174 -
Molecular Imaging 2022Positron emission tomography (PET) imaging with prostate-specific membrane antigen- (PSMA-) binding tracers has been found incidentally to demonstrate uptake in CNS... (Review)
Review
INTRODUCTION
Positron emission tomography (PET) imaging with prostate-specific membrane antigen- (PSMA-) binding tracers has been found incidentally to demonstrate uptake in CNS tumors. Following the encouraging findings of several such case reports, there is a growing interest in the potential application of PSMA-targeted PET imaging for diagnostics, theranostics, and monitoring of CNS tumors. This is a systematic literature review on PSMA-binding tracers in CNS tumors.
METHODS
A PubMed search was conducted, including preclinical and clinical reports. One hundred and twelve records were identified, and after screening, 56 were included in the final report.
RESULTS
Tissue studies demonstrated PSMA expression in tumor vascular endothelial cells, without expression in normal brain tissue, though the extent and intensity of staining varied by anti-PSMA antibody and methodology. Most included studies reported on gliomas, which showed strong PSMA ligand uptake and more favorable tumor to background ratios than other PET tracers. There are also case reports demonstrating PSMA ligand uptake in prostate cancer brain metastases, nonprostate cancer brain metastases, and meningiomas. We also review the properties of the various PSMA-binding radiotracers available. Therapeutic and theranostic applications of PSMA-binding tracers have been studied, including labeled alpha- and beta-ray emitting isotopes, as well as PSMA targeting in directing MRI-guided focused ultrasound.
CONCLUSIONS
There is a potential application for PSMA-targeted PET in neuro-oncology as a combination of diagnostic and therapeutic use, as a theranostic modality for managing CNS tumors. Further research is needed regarding the mechanism(s) of PSMA expression in CNS tumors and its differential performance by tumor type.
Topics: Brain Neoplasms; Endothelial Cells; Humans; Ligands; Male; Neuroimaging; Positron-Emission Tomography; Prostate; Prostatic Neoplasms; Radiopharmaceuticals
PubMed: 35517711
DOI: 10.1155/2022/5358545 -
Frontiers in Allergy 2022Drug hypersensitivity (DH) reactions are clinically unusual because the underlying immune stimulations are not antigen-driven, but due to non-covalent drug-protein...
Drug hypersensitivity (DH) reactions are clinically unusual because the underlying immune stimulations are not antigen-driven, but due to non-covalent drug-protein binding. The drugs may bind to immune receptors like HLA or TCR which elicits a strong T cell reaction (p-i concept), the binding may enhance the affinity of antibodies (enhanced affinity model), or drug binding may occur on soluble proteins which imitate a true antigen (fake antigen model). These novel models of DH could have a major impact on how to perform risk assessments in drug development. Herein, we discuss the difficulties of detecting such non-covalent, labile and reversible, but immunologically relevant drug-protein interactions early on in drug development. The enormous diversity of the immune system, varying interactions, and heterogeneous functional consequences make it to a challenging task. We propose that a realistic approach to detect clinically relevant non-covalent drug interactions for a new drug could be based on a combination of cell culture assays (using a panel of HLA typed donor cells) and functional analyses, supplemented by structural analysis () of the reactive cells/molecules. When drug-reactive cells/molecules with functional impact are detected in these risk assessments, a close clinical monitoring of the drug may reveal the true incidence of DH, as suppressing but also enhancing factors occurring can influence the clinical manifestation of a DH.
PubMed: 35386664
DOI: 10.3389/falgy.2022.827893 -
Anais Brasileiros de Dermatologia 2022Leishmaniasis is caused by an intracellular protozoan of the Leishmania genus. Mannose-binding lectin (MBL) is a serum complement protein and recognizes lipoprotein... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Leishmaniasis is caused by an intracellular protozoan of the Leishmania genus. Mannose-binding lectin (MBL) is a serum complement protein and recognizes lipoprotein antigens in protozoa and the bacterial plasma membrane. Nucleotide variants in the promoter region and exon 1 of the MBL gene can influence its expression or change its molecular structure.
OBJECTIVE
To evaluate, through a systematic review, case-control studies of the genetic association of variants in the MBL2 gene and the risk of developing leishmaniasis.
METHODS
This review carried out a search in PubMed, Science Direct, Cochrane Library, Scopus and Lilacs databases for case-control publications with six polymorphisms in the mannose-binding Lectin gene. The following strategy was used: P = Patients at risk of leishmaniasis; I = Presence of polymorphisms; C = Absence of polymorphisms; O = Occurrence of leishmaniasis. Four case/control studies consisting of 791 patients with leishmaniasis and 967 healthy subjects (Control) are included in this meta-analysis. The association of variants in the mannose-binding Lectin gene and leishmaniasis under the allelic genetic model, -550 (Hvs. L), -221 (X vs. Y), +4 (Q vs. P), CD52 (A vs. D), CD54 (A vs. B), CD57 (A vs. C) and A/O genotype (A vs. O) was evaluated. International Prospective Register of Systematic Reviews (PROSPERO): CRD42020201755.
RESULTS
The meta-analysis results for any allelic genetic model showed no significant association for the variants within the promoter, the untranslated region, and exon 1, as well as for the wild-type A allele and mutant allele O with leishmaniasis.
STUDY LIMITATIONS
Caution should be exercised when interpreting these results, as they are based on a few studies, which show divergent results when analyzed separately.
CONCLUSIONS
This meta-analysis showed a non-significant association between the rs11003125, rs7096206, rs7095891, rs5030737, rs1800450, and rs1800451 polymorphisms of the Mannose-binding Lectin gene and leishmaniasis in any allelic and heterogeneous evaluation.
Topics: Alleles; Genetic Predisposition to Disease; Genotype; Humans; Leishmaniasis; Mannose-Binding Lectin; Polymorphism, Single Nucleotide
PubMed: 35331599
DOI: 10.1016/j.abd.2021.08.004