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FEMS Microbiology Reviews Aug 2021Streptococcus pneumoniae synthesizes >100 types of capsular polysaccharides (CPSs). While the diversity of the enzymes and transporters involved is enormous, it is not... (Review)
Review
Streptococcus pneumoniae synthesizes >100 types of capsular polysaccharides (CPSs). While the diversity of the enzymes and transporters involved is enormous, it is not limitless. In this review, we summarized the recent progress on elucidating the structure-function relationships of CPSs, the mechanisms by which they are synthesized, how their synthesis is regulated, the host immune response against them and the development of novel pneumococcal vaccines. Based on the genetic and structural information available, we generated provisional models of the CPS repeating units that remain unsolved. In addition, to facilitate cross-species comparisons and assignment of glycosyltransferases, we illustrated the biosynthetic pathways of the known CPSs in a standardized format. Studying the intricate steps of pneumococcal CPS assembly promises to provide novel insights for drug and vaccine development as well as improve our understanding of related pathways in other species.
Topics: Pneumococcal Vaccines; Polysaccharides, Bacterial; Streptococcus pneumoniae; Vaccine Development
PubMed: 33338218
DOI: 10.1093/femsre/fuaa067 -
Current Topics in Microbiology and... 2022In the past 20 years, the mRNA vaccine technology has evolved from the first proof of concept to the first licensed vaccine against emerging pandemics such as... (Review)
Review
In the past 20 years, the mRNA vaccine technology has evolved from the first proof of concept to the first licensed vaccine against emerging pandemics such as SARS-CoV-2. Two mRNA vaccines targeting SARS-CoV-2 have received emergency use authorization by US FDA, conditional marketing authorization by EMA, as well as multiple additional national regulatory authorities. The simple composition of an mRNA encoding the antigen formulated in a lipid nanoparticle enables a fast adaptation to new emerging pathogens. This can speed up vaccine development in pandemics from antigen and sequence selection to clinical trial to only a few months. mRNA vaccines are well tolerated and efficacious in animal models for multiple pathogens and will further contribute to the development of vaccines for other unaddressed diseases. Here, we give an overview of the mRNA vaccine design and factors for further optimization of this new promising technology and discuss current knowledge on the mode of action of mRNA vaccines interacting with the innate and adaptive immune system.
Topics: Animals; COVID-19; Models, Animal; mRNA Vaccines; COVID-19 Vaccines; Vaccine Development
PubMed: 33591423
DOI: 10.1007/82_2020_230 -
Frontiers in Immunology 2023Crimean-Congo hemorrhagic fever (CCHF) is the most prevalent tick-borne viral disease affecting humans. The disease is life-threatening in many regions of the developing... (Review)
Review
Crimean-Congo hemorrhagic fever (CCHF) is the most prevalent tick-borne viral disease affecting humans. The disease is life-threatening in many regions of the developing world, including Africa, Asia, the Middle East, and Southern Europe. In line with the rapidly increasing disease prevalence, various vaccine strategies are under development. Despite a large number of potential vaccine candidates, there are no approved vaccines as of yet. This paper presents a detailed comparative analysis of current efforts to develop vaccines against CCHFV, limitations associated with current efforts, and future research directions.
Topics: Humans; Hemorrhagic Fever Virus, Crimean-Congo; Hemorrhagic Fever, Crimean; Africa; Asia; Vaccine Development
PubMed: 37753088
DOI: 10.3389/fimmu.2023.1238882 -
Journal of Medical Virology Mar 2022Severe acute respiratory syndrome coronavirus 2 is associated with a severe respiratory disease in China, that rapidly spread across continents. Since the beginning of... (Review)
Review
Severe acute respiratory syndrome coronavirus 2 is associated with a severe respiratory disease in China, that rapidly spread across continents. Since the beginning of the pandemic, available data suggested the asymptomatic transmission and patients were treated with specific drugs with efficacy and safety data not always satisfactory. The aim of this review is to describe the vaccines developed by three companies, Pfizer-BioNTech, Moderna, and University of Oxford/AstraZeneca, in terms of both technological and pharmaceutical formulation, safety, efficacy, and immunogenicity. A critical analysis of Phases 1, 2, and 3 clinical trial results available was conducted, comparing the three vaccine candidates, underlining their similarities and differences. All candidates showed consistent efficacy and tolerability; although some differences can be noted, such as their technological formulation, temperature storage, which will be related to logistics and costs. Further studies will be necessary to evaluate long-term effects and to assess the vaccine safety and efficacy in the general population.
Topics: COVID-19; COVID-19 Vaccines; Humans; SARS-CoV-2; Technology; Vaccine Development
PubMed: 34713912
DOI: 10.1002/jmv.27425 -
Science (New York, N.Y.) Mar 2022A diverse array of successful, first-generation SARS-CoV-2 vaccines have played a huge role in efforts to bring the COVID-19 pandemic under control, even though... (Review)
Review
A diverse array of successful, first-generation SARS-CoV-2 vaccines have played a huge role in efforts to bring the COVID-19 pandemic under control, even though inequitable distribution still leaves many vulnerable. Additional challenges loom for the next phase. These include optimizing the immunological rationale for boosting-how often and with what-and the best approaches for building a future-proofed, durable immune repertoire to protect against oncoming viral variants, including in children. The landscape of vaccine producers and technologies is likely to become even more heterogeneous. There is a need now for appraisal of future approaches: While some favor frequent boosting with the first-generation, ancestral spike vaccines, others propose frequent readjustment using current variant sequences, polyvalent vaccines, or pan-coronavirus strategies.
Topics: Adult; Antigens, Viral; COVID-19; COVID-19 Vaccines; Child; Humans; Immune Evasion; Immunization, Secondary; Immunogenicity, Vaccine; Mass Vaccination; SARS-CoV-2; Vaccination Hesitancy; Vaccine Development
PubMed: 35271316
DOI: 10.1126/science.abn1755 -
Methods in Molecular Biology (Clifton,... 2022Fish health management has become a critical component of disease control and is invaluable for improved harvests and sustainable aquaculture. Vaccination is generally...
Fish health management has become a critical component of disease control and is invaluable for improved harvests and sustainable aquaculture. Vaccination is generally accepted as the most effective prophylactic measure for fish disease prevention, on environmental, social, and economic grounds. Although the historical approach for developing fish vaccines was based on the principle of Louis Pasteur's "isolate, inactivate and inject," but their weak immunogenicity and low efficacies in many cases, have shifted the focus of fish vaccine development from traditional to next-generation technologies. However, before any fish vaccine can be successfully commercialized, several hurdles need to be overcome regarding the production cost, immunogenicity, effectiveness, mode of administration, environmental safety, and associated regulatory concerns. In this context, the chapter summarises the basic aspects of fish vaccination such as type of vaccine, modalities of vaccine delivery, the immunological basis of fish immunization as well as different challenges associated with the development process and future opportunities.
Topics: Animals; Aquaculture; Fish Diseases; Fishes; Vaccination; Vaccine Development; Vaccines
PubMed: 34816404
DOI: 10.1007/978-1-0716-1888-2_9 -
The Lancet. Infectious Diseases Nov 2023An Escherichia coli-produced human papillomavirus (HPV) 16 and 18 bivalent vaccine (Cecolin) was prequalified by WHO in 2021. This study aimed to compare the... (Randomized Controlled Trial)
Randomized Controlled Trial
Head-to-head immunogenicity comparison of an Escherichia coli-produced 9-valent human papillomavirus vaccine and Gardasil 9 in women aged 18-26 years in China: a randomised blinded clinical trial.
BACKGROUND
An Escherichia coli-produced human papillomavirus (HPV) 16 and 18 bivalent vaccine (Cecolin) was prequalified by WHO in 2021. This study aimed to compare the immunogenicity of the E coli-produced HPV 9-valent vaccine Cecolin 9 (against HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58) with Gardasil 9.
METHODS
This was a randomised, single-blind trial conducted in China. Healthy non-pregnant women aged 18-26 years, who were not breastfeeding and with no HPV vaccination history, were enrolled in the Ganyu Centre for Disease Control and Prevention (Lianyungang City, Jiangsu Province, China). Women were stratified by age (18-22 years and 23-26 years) and randomly assigned (1:1) using a permutated block size of eight to receive three doses of Cecolin 9 or Gardasil 9 at day 0, day 45, and month 6. All participants, as well as study personnel without access to the vaccines, were masked. Neutralising antibodies were measured by a triple-colour pseudovirion-based neutralisation assay. The primary outcomes, seroconversion rates and geometric mean concentrations (GMCs) at month 7, were analysed in the per-protocol set for immunogenicity (PPS-I). Non-inferiority was identified for the lower limit of the 95% CI of the GMC ratio (Cecolin 9 vs Gardasil 9) at a margin of 0·5 and a seroconversion rate difference (Cecolin 9-Gardasil 9) at a margin of -5%. This study was registered at ClinicalTrials.gov (NCT04782895) and is completed.
FINDINGS
From March 14 to 18, 2021, a total of 553 potential participants were screened, of which 244 received at least one dose of Cecolin 9 and 243 received at least one dose of Gardasil 9. The seroconversion rates for all HPV types in both groups were 100% in the PPS-I, with the values of the lower limits of 95% CIs for seroconversion rate differences ranging between -1·8% and -1·7%. The GMC ratios of five types were higher than 1·0, with the highest ratio, for HPV 58, at 1·65 (95% CI 1·38-1·97), and those of four types were lower than 1·0, with the lowest ratio, for HPV 11, at 0·79 (0·68-0·93). The incidence of adverse reactions in both groups was similar (43% [104/244] vs 47% [115/243]).
INTERPRETATION
Cecolin 9 induced non-inferior HPV type-specific immune responses compared with Gardasil 9 and is a potential candidate to accelerate the elimination of cervical cancer by allowing for global accessibility to 9-valent HPV vaccinations, especially in low-income and middle-income countries.
FUNDING
National Natural Science Foundation, Fujian Provincial Natural Science Foundation, Xiamen Science and Technology Plan Project, Fundamental Research Funds for the Central Universities, CAMS Innovation Fund for Medical Sciences of China, and Xiamen Innovax.
Topics: Humans; Female; Escherichia coli; Human Papillomavirus Viruses; Papillomavirus Infections; Single-Blind Method; Papillomavirus Vaccines; China; Immunogenicity, Vaccine; Antibodies, Viral; Double-Blind Method
PubMed: 37475116
DOI: 10.1016/S1473-3099(23)00275-X -
Methods in Molecular Biology (Clifton,... 2022Arthropod vectors account for a number of animal and human diseases, posing substantial threats to health and safety on a global scale. Ticks are considered as one of...
Arthropod vectors account for a number of animal and human diseases, posing substantial threats to health and safety on a global scale. Ticks are considered as one of the most prominent vectors, as they can parasitize almost any vertebrate class and transmit a multitude of infectious diseases, particularly ones that affect humans and domestic animals. While various tick species elicit different tick-borne infections in specific geographic regions, single species can have widespread effects, such as blacklegged ticks, which are widely distributed across the eastern United States and can transmit a variety of infections, including Lyme borreliosis, anaplasmosis, relapsing fever disease, ehrlichiosis, babesiosis, and Powassan virus disease. Despite increasing awareness about ticks as serious disease vectors, effective vaccines against most tick-borne infections are not available. Previously, the successful development of an anti-tick vaccine for use in veterinary animals was based on an 86-kDa midgut antigen from Rhipicephalus (formerly Boophilus) microplus ticks. Herein we describe the fundamentals of vaccine development using protein antigens as model vaccinogen candidates, beginning with the cloning, expression, and purification of recombinant proteins, host immunization, and the assessment of protective efficacy in laboratory settings using a tick-borne murine model of Lyme borreliosis.
Topics: Animals; Antigens; Humans; Ixodes; Lyme Disease; Mice; Tick-Borne Diseases; United States; Vaccine Development; Vaccines
PubMed: 34816411
DOI: 10.1007/978-1-0716-1888-2_16 -
Trends in Microbiology Nov 2021Antimicrobial resistance is an increasing global threat and alternative treatments substituting failing antibiotics are urgently needed. Vaccines are recognized as... (Review)
Review
Antimicrobial resistance is an increasing global threat and alternative treatments substituting failing antibiotics are urgently needed. Vaccines are recognized as highly effective tools to mitigate antimicrobial resistance; however, the selection of bacterial antigens as vaccine candidates remains challenging. In recent years, advances in mass spectrometry-based proteomics have led to the development of so-called immunopeptidomics approaches that allow the untargeted discovery of bacterial epitopes that are presented on the surface of infected cells. Especially for intracellular bacterial pathogens, immunopeptidomics holds great promise to uncover antigens that can be encoded in viral vector- or nucleic acid-based vaccines. This review provides an overview of immunopeptidomics studies on intracellular bacterial pathogens and considers future directions and challenges in advancing towards next-generation vaccines.
Topics: Antigens, Bacterial; Bacterial Vaccines; Mass Spectrometry; Proteomics; Vaccine Development
PubMed: 34030969
DOI: 10.1016/j.tim.2021.04.010 -
Pharmaceutical Research Nov 2022Exosomes are cell-derived components composed of proteins, lipid, genetic information, cytokines, and growth factors. They play a vital role in immune modulation,... (Review)
Review
Exosomes are cell-derived components composed of proteins, lipid, genetic information, cytokines, and growth factors. They play a vital role in immune modulation, cell-cell communication, and response to inflammation. Immune modulation has downstream effects on the regeneration of damaged tissue, promoting survival and repair of damaged resident cells, and promoting the tumor microenvironment via growth factors, antigens, and signaling molecules. On top of carrying biological messengers like mRNAs, miRNAs, fragmented DNA, disease antigens, and proteins, exosomes modulate internal cell environments that promote downstream cell signaling pathways to facilitate different disease progression and induce anti-tumoral effects. In this review, we have summarized how vaccines modulate our immune response in the context of cancer and infectious diseases and the potential of exosomes as vaccine delivery vehicles. Both pre-clinical and clinical studies show that exosomes play a decisive role in processes like angiogenesis, prognosis, tumor growth metastasis, stromal cell activation, intercellular communication, maintaining cellular and systematic homeostasis, and antigen-specific T- and B cell responses. This critical review summarizes the advancement of exosome based vaccine development and delivery, and this comprehensive review can be used as a valuable reference for the broader delivery science community.
Topics: Humans; Exosomes; Vaccine Development; Tumor Microenvironment; Neoplasms; Cell Communication
PubMed: 35028802
DOI: 10.1007/s11095-021-03143-4