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Blood Dec 2023
Topics: Humans; Adenoviridae; Adenovirus Vaccines; Heparin; Thromboinflammation; Vaccines
PubMed: 38153773
DOI: 10.1182/blood.2023022900 -
Clinical Infectious Diseases : An... Sep 2022Rare cases of thrombosis and thrombocytopenia (thrombosis with thrombocytopenia syndrome [TTS]) have been associated with 2 coronavirus disease 2019 adenovirus vector... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Rare cases of thrombosis and thrombocytopenia (thrombosis with thrombocytopenia syndrome [TTS]) have been associated with 2 coronavirus disease 2019 adenovirus vector vaccines: the ChAdOx1 nCoV-19 Vaxzevria vaccine (Oxford/AstraZeneca) and the JNJ-7836735 Johnson & Johnson vaccine (Janssen). It is unknown if TTS is a class-mediated effect of adenovirus-based vaccines or if it could worsen known hypercoagulable states. Since most cases of TTS happen in women of childbearing age, pregnancy is a crucial risk factor to assess. Understanding these risks is important for advising vaccine recipients and future adenovirus vector vaccine development.
METHODS
To explore the potential associations of adenovirus-based vaccine components with symptoms of TTS in the general clinical trial population and in pregnant women in clinical trials, we conducted a systematic review and meta-analysis of adenovirus-based vector vaccines to document cases of thrombocytopenia, coagulopathy, and or pregnancy from 1 January 1966 to 9 August 2021.
RESULTS
We found 167 articles from 159 studies of adenovirus vector-based vaccines, 123 of which targeted infectious diseases. In the general population, 20 studies reported an event of thrombocytopenia and 20 studies indicated some coagulopathy. Among pregnant women, of the 28 studies that reported a total of 1731 pregnant women, thrombocytopenia or coagulopathy were not reported.
CONCLUSIONS
In this systematic review and meta-analysis, there was no class-wide effect of adenovirus vector vaccines toward thrombocytopenia or coagulopathy events in the general population or in pregnant women.
Topics: Adenoviridae; Adenovirus Vaccines; COVID-19; ChAdOx1 nCoV-19; Female; Humans; Pregnancy; Thrombocytopenia; Thrombosis; Vaccines
PubMed: 35134164
DOI: 10.1093/cid/ciac080 -
European Journal of Immunology Jun 2023Replication-incompetent adenovirus (Ad) vector and mRNA-lipid nanoparticle (LNP) constructs represent two modular vaccine platforms that have attracted substantial... (Review)
Review
Replication-incompetent adenovirus (Ad) vector and mRNA-lipid nanoparticle (LNP) constructs represent two modular vaccine platforms that have attracted substantial interest over the past two decades. Due to the COVID-19 pandemic and the rapid development of multiple successful vaccines based on these technologies, there is now clear real-world evidence of the utility and efficacy of these platforms. Considerable optimization and refinement efforts underpin the successful application of these technologies. Despite this, our understanding of the specific pathways and processes engaged by these vaccines to stimulate the immune response remains incomplete. This review will synthesize our current knowledge of the specific mechanisms by which CD8 T cell and antibody responses are induced by each of these vaccine platforms, and how this can be impacted by specific vaccine construction techniques. Key gaps in our knowledge are also highlighted, which can hopefully focus future studies.
Topics: Humans; mRNA Vaccines; Pandemics; COVID-19; Genetic Vectors; Adenoviridae
PubMed: 36330560
DOI: 10.1002/eji.202250022 -
Frontiers in Microbiology 2021Vaccination is the most effective method to date to prevent viral diseases. It intends to mimic a naturally occurring infection while avoiding the disease, exposing our... (Review)
Review
Vaccination is the most effective method to date to prevent viral diseases. It intends to mimic a naturally occurring infection while avoiding the disease, exposing our bodies to viral antigens to trigger an immune response that will protect us from future infections. Among different strategies for vaccine development, recombinant vaccines are one of the most efficient ones. Recombinant vaccines use safe viral vectors as vehicles and incorporate a transgenic antigen of the pathogen against which we intend to generate an immune response. These vaccines can be based on replication-deficient viruses or replication-competent viruses. While the most effective strategy involves replication-competent viruses, they must be attenuated to prevent any health hazard while guaranteeing a strong humoral and cellular immune response. Several attenuation strategies for adenoviral-based vaccine development have been contemplated over time. In this paper, we will review them and discuss novel approaches based on the principle that protein synthesis from individual genes can be modulated by codon usage bias manipulation. We will summarize vaccine approaches that consider recoding of viral proteins to produce adenoviral attenuation and recoding of the transgene antigens for both viral attenuation and efficient viral epitope expression.
PubMed: 33643266
DOI: 10.3389/fmicb.2021.633946 -
Human Vaccines & Immunotherapeutics Dec 2023Herpes zoster (HZ) results from waning immunity following childhood infection with varicella zoster virus (VZV) but is preventable by vaccination with recombinant HZ...
Herpes zoster (HZ) results from waning immunity following childhood infection with varicella zoster virus (VZV) but is preventable by vaccination with recombinant HZ vaccine or live HZ vaccine (two doses or one dose, respectively). Vaccine efficacy declines with age, live HZ vaccine is contraindicated in immunosuppressed individuals, and severe local reactogenicity of recombinant HZ vaccine is seen in up to 20% of older adults, indicating a potential need for new vaccines. Nonreplicating chimpanzee adenovirus (ChAd) vectors combine potent immunogenicity with well-established reactogenicity and safety profiles. We evaluated the cellular and humoral immunogenicity of ChAdOx1 encoding VZV envelope glycoprotein E (ChAdOx1-VZVgE) in mice using IFN-γ ELISpot, flow cytometry with intracellular cytokine staining, and ELISA. In outbred CD-1 mice, one dose of ChAdOx1-VZVgE (1 × 10 infectious units) elicited higher gE-specific T cell responses than two doses of recombinant HZ vaccine (1 µg) or one dose of live HZ vaccine (1.3 × 10 plaque-forming units). Antibody responses were higher with two doses of recombinant HZ vaccine than with two doses of ChAdOx1-VZVgE or one dose of live HZ vaccine. ChAdOx1-VZVgE boosted T cell and antibody responses following live HZ vaccine priming. The frequencies of polyfunctional CD4+ and CD8+ T cells expressing more than one cytokine (IFN-γ, TNF-α and IL-2) were higher with ChAdOx1-VZVgE than with the conventional vaccines. Results were similar in young and aged BALB/c mice. These findings support the clinical development of ChAdOx1-VZVgE for prevention of HZ in adults aged 50 years or over, including those who have already received conventional vaccines.
Topics: Animals; Mice; Herpesvirus 3, Human; Adenovirus Vaccines; Adenoviridae; Antibodies, Viral; Herpes Zoster; Herpes Zoster Vaccine; Vaccination; Cytokines; Immunogenicity, Vaccine
PubMed: 36785938
DOI: 10.1080/21645515.2023.2175558 -
Clinical Infectious Diseases : An... Aug 2022We assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)-vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost... (Randomized Controlled Trial)
Randomized Controlled Trial
Safety and Immunogenicity of a Recombinant Adenovirus Type-5-Vectored Coronavirus Disease 2019 (COVID-19) Vaccine With a Homologous Prime-Boost Regimen in Healthy Participants Aged ≥6 Years: A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Trial.
BACKGROUND
We assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)-vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost regimens in healthy participants aged ≥6 years.
METHODS
In this randomized, double-blind, placebo-controlled trial, participants received vaccine or placebo 56 days apart. Enzyme-linked immunosorbent assay (ELISA) antibodies to the receptor binding domain (RBD) and pseudovirus neutralizing antibodies were detected. Adverse events were monitored for 28 days following each vaccination.
RESULTS
A total of 430 participants were enrolled in the study, with 30 participants aged 18-55 years (MID cohort), 250 aged ≥56 years (OLD cohort), and 150 aged 6-17 years (MIN cohort). Ad5-vectored COVID-19 vaccine induced significant RBD-specific ELISA antibodies that decreased with increasing age, with geometric mean titers (GMTs) of 1037.5 in the MIN cohort, 647.2 in the MID cohort, and 338.0 in the OLD cohort receiving 5 × 1010 viral particles on day 28 following boost vaccination. Pseudovirus neutralizing antibodies showed a similar pattern, with GMTs of 168.0 in the MIN cohort, 76.8 in the MID cohort, and 79.7 in the OLD cohort. A single dose in children and adolescents induced higher antibody responses than that elicited by 2 doses in adults, with GMTs of 1091.6 and 96.6 for ELISA antibody and neutralizing antibody, respectively. Homologous prime-boost vaccination was safe and tolerable.
CONCLUSIONS
Ad5-vectored COVID-19 vaccine with a single dose was safe and induced robust immune responses in children and adolescents aged 6-17 years. A prime-boost regimen needs further exploration for Ad5-vectored COVID-19 vaccine.Ad5-vectored COVID-19 vaccine with a single dose was safe and tolerated, and induced robust immune responses in children and adolescents aged 6-17 years. The boosting effect on immune responses of the homologous prime-boost regime given 56 days apart was limited.
CLINICAL TRIALS REGISTRATION
NCT04566770.
Topics: Adenoviridae; Adolescent; Adult; Antibodies, Neutralizing; Antibodies, Viral; COVID-19; COVID-19 Vaccines; Child; Double-Blind Method; Healthy Volunteers; Humans; Immunogenicity, Vaccine; Viral Vaccines
PubMed: 34551104
DOI: 10.1093/cid/ciab845 -
Viruses Dec 2023Efficient and targeted delivery of a DNA payload is vital for developing safe gene therapy. Owing to the recent success of commercial oncolytic vector and multiple... (Review)
Review
Efficient and targeted delivery of a DNA payload is vital for developing safe gene therapy. Owing to the recent success of commercial oncolytic vector and multiple COVID-19 vaccines, adenovirus vectors are back in the spotlight. Adenovirus vectors can be used in gene therapy by altering the wild-type virus and making it replication-defective; specific viral genes can be removed and replaced with a segment that holds a therapeutic gene, and this vector can be used as delivery vehicle for tissue specific gene delivery. Modified conditionally replicative-oncolytic adenoviruses target tumors exclusively and have been studied in clinical trials extensively. This comprehensive review seeks to offer a summary of adenovirus vectors, exploring their characteristics, genetic enhancements, and diverse applications in clinical and preclinical settings. A significant emphasis is placed on their crucial role in advancing cancer therapy and the latest breakthroughs in vaccine clinical trials for various diseases. Additionally, we tackle current challenges and future avenues for optimizing adenovirus vectors, promising to open new frontiers in the fields of cell and gene therapies.
Topics: Humans; COVID-19 Vaccines; Virus Replication; Neoplasms; Genetic Vectors; Adenoviridae; Genetic Therapy; Vaccines
PubMed: 38140619
DOI: 10.3390/v15122378 -
Vaccine Sep 2021In an effort to control the COVID-19 pandemic, large-scale vaccination is being implemented in various countries using anti-SARS-CoV-2 vaccines based on mRNAs,... (Review)
Review
In an effort to control the COVID-19 pandemic, large-scale vaccination is being implemented in various countries using anti-SARS-CoV-2 vaccines based on mRNAs, adenovirus vectors, and inactivated viruses. However, there are concerns regarding adverse effects, such as the induction of fever attributed to mRNA vaccines and pre-existing immunity against adenovirus vectored vaccines or their possible involvement in the development of thrombosis. The induction of antibodies against the adenovirus vector itself constitutes another hindrance, rendering boosting vaccinations ineffective. Additionally, it has been questioned whether inactivated vaccines that predominantly induce humoral immunity are effective against newly arising variants, as some isolated strains were found to be resistant to the serum from COVID-19-recovered patients. Although the number of vaccinated people is steadily increasing on a global scale, it is still necessary to develop vaccines to address the difficulties and concerns mentioned above. Among the various vaccine modalities, live attenuated vaccines have been considered the most effective, since they closely replicate a natural infection without the burden of the disease. In our attempt to provide an additional option to the repertoire of COVID-19 vaccines, we succeeded in isolating temperature-sensitive strains with unique phenotypes that could serve as seeds for a live attenuated vaccine. In this review article, we summarize the characteristics of the currently approved SARS-CoV-2 vaccines and discuss their advantages and disadvantages. In particular, we focus on the novel temperature-sensitive variants of SARS-CoV-2 that we have recently isolated, and their potential application as live-attenuated vaccines. Based on a thorough evaluation of the different vaccine modalities, we argue that it is important to optimize usage not only based on efficacy, but also on the phases of the pandemic. Our findings can be used to inform vaccination practices and improve global recovery from the COVID-19 pandemic.
Topics: COVID-19; COVID-19 Vaccines; Humans; Pandemics; SARS-CoV-2; Vaccines, Attenuated
PubMed: 34426024
DOI: 10.1016/j.vaccine.2021.08.018 -
Vaccine Oct 2023Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes severe watery diarrhea, vomiting, dehydration and high mortality in piglets,...
Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus that causes severe watery diarrhea, vomiting, dehydration and high mortality in piglets, resulting in significant economic losses by the global pig industry. Recently, PDCoV has also shown the potential for cross-species transmission. However, there are currently few vaccine studies and no commercially available vaccines for PDCoV. Hence, here, two novel human adenovirus 5 (Ad5)-vectored vaccines expressing codon-optimized forms of the PDCoV spike (S) glycoprotein (Ad-PD-tPA-Sopt) and S1 glycoprotein (Ad-PD-oriSIP-S1opt) were constructed, and their effects were evaluated via intramuscular (IM) injection in BALB/c mice with different doses and times. Both vaccines elicited robust humoral and cellular immune responses; moreover, Ad-PD-tPA-Sopt-vaccinated mice after two IM injections with 10 infectious units (IFU)/mouse had significantly higher anti-PDCoV-specific neutralizing antibody titers. In contrast, the mice immunized with Ad-PD-tPA-Sopt via oral gavage (OG) did not generate robust systemic and mucosal immunity. Thus, IM Ad-PD-tPA-Sopt administration is a promising strategy against PDCoV and provides useful information for future animal vaccine development.
Topics: Humans; Animals; Swine; Mice; Adenovirus Vaccines; Vaccines; Glycoproteins; Immunity, Cellular; Adenoviridae; Swine Diseases; Coronavirus Infections
PubMed: 37777448
DOI: 10.1016/j.vaccine.2023.09.053 -
Veterinary Research Communications Dec 2023Haemorrhagic enteritis is an economically significant disease reported in the majority of the countries where turkeys are raised intensively; it is caused by Turkey...
Haemorrhagic enteritis is an economically significant disease reported in the majority of the countries where turkeys are raised intensively; it is caused by Turkey adenovirus 3 (TAdV-3). The aim of this study was to analyse and compare the ORF1 gene 3' region from turkey haemorrhagic enteritis virus (THEV) vaccine-like and field strains in order to develop a molecular diagnostic method to differentiate the strains from each other. Eighty samples were analysed by sequencing and phylogenetic analyses using a new set of polymerase chain reaction (PCR) primers targeting a genomic region spanning the partial ORF1, hyd and partial IVa2 gene sequences. A commercial live vaccine was also included in the analysis. The results showed that 56 of the 80 sequences obtained in this study showed ≥99.8% nucleotide identity with the homologous vaccine strain sequence. Three non-synonymous mutations - ntA1274G (aaI425V), ntA1420C (aaQ473H) and ntG1485A (aaR495Q) - were detected in the THEV field strains but not in the vaccine strain. Phylogenetic analysis confirmed the clustering of the field and vaccine-like strains in different phylogenetic branches. In conclusion, the method employed in this study could be a useful tool towards making a correct diagnosis. The data could contribute to the knowledge of field distribution of THEV strains and increase the limited existing information available on native isolates around the world.
Topics: Animals; Siadenovirus; Poultry Diseases; Phylogeny; Vaccines; Enteritis; Turkeys
PubMed: 37289400
DOI: 10.1007/s11259-023-10148-4