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Frontiers in Immunology 2024Dengue, caused by the dengue virus (DENV), affects millions of people worldwide every year. This virus has two distinct life cycles, one in the human and another in the... (Review)
Review
Dengue, caused by the dengue virus (DENV), affects millions of people worldwide every year. This virus has two distinct life cycles, one in the human and another in the mosquito, and both cycles are crucial to be controlled. To control the vector of DENV, the mosquito , scientists employed many techniques, which were later proved ineffective and harmful in many ways. Consequently, the attention shifted to the development of a vaccine; researchers have targeted the E protein, a surface protein of the virus and the NS1 protein, an extracellular protein. There are several types of vaccines developed so far, such as live attenuated vaccines, recombinant subunit vaccines, inactivated virus vaccines, viral vectored vaccines, DNA vaccines, and mRNA vaccines. Along with these, scientists are exploring new strategies of developing improved version of the vaccine by employing recombinant DNA plasmid against NS1 and also aiming to prevent the infection by blocking the DENV life cycle inside the mosquitoes. Here, we discussed the aspects of research in the field of vaccines until now and identified some prospects for future vaccine developments.
Topics: Animals; Humans; Dengue; Dengue Virus; Dengue Vaccines; Mosquito Vectors; Vaccines, Attenuated; Vaccines, Inactivated; Vaccines, DNA; Viral Vaccines
PubMed: 38487527
DOI: 10.3389/fimmu.2024.1362780 -
Infectious Diseases of Poverty Dec 2021African swine fever (ASF) is a fatal hemorrhagic disease in domestic pigs and wild boar caused by African swine fever virus (ASFV). Since ASF has been introduced into...
BACKGROUND
African swine fever (ASF) is a fatal hemorrhagic disease in domestic pigs and wild boar caused by African swine fever virus (ASFV). Since ASF has been introduced into Europe and Asia, the major pig-raising areas, posing a huge threat to the pork industry worldwide. Currently, prevention and control of ASF are basically dependent on strict biosecurity measures and stamping-out policy once ASF occurs.
MAIN TEXT
The major risks of ASF spread are insufficient biosecurity measures and human behaviors. Therefore, a safe and effective vaccine seems to be a reasonable demand for the prevention and control of ASF. Due to the efficacy advantage over other types of vaccines, live attenuated vaccines (LAVs), especially virulence-associated genes deleted vaccines, are likely to be put into emergency and conditional use in restricted areas if ASF is out of control in a country with a huge pig population and pork consumption, like China. However, the safety, efficacy, and genetic stability of current candidate ASF LAVs require comprehensive clinical evaluations prior to country-wide field application. Several critical issues need to be addressed to commercialize an ideal ASF LAV, including a stable cell line for manufacturing vaccines, differentiation of infected from vaccinated animals (DIVA), and cross-protection from different genotypes.
CONCLUSION
A safe and effective DIVA vaccine and an accompanying diagnostic assay will facilitate the prevention, control, and eradication of ASF, which is quite challenging in the near future.
Topics: African Swine Fever; African Swine Fever Virus; Animals; Biosecurity; Sus scrofa; Swine; Vaccines, Attenuated; Viral Vaccines
PubMed: 34949228
DOI: 10.1186/s40249-021-00920-6 -
Viruses Apr 2022African swine fever (ASF) is causing a pandemic affecting swine in a large geographical area of the Eastern Hemisphere, from Central Europe to East and Southeast Asia,... (Review)
Review
African swine fever (ASF) is causing a pandemic affecting swine in a large geographical area of the Eastern Hemisphere, from Central Europe to East and Southeast Asia, and recently in the Americas, the Dominican Republic and Haiti. The etiological agent, ASF virus (ASFV), infects both domestic and wild swine and produces a variety of clinical presentations depending on the virus strain and the genetics of the pigs infected. No commercial vaccines are currently available, although experimental recombinant live attenuated vaccine candidates have been shown to be efficacious in protecting animals against disease when challenged with homologous virulent strains. This review attempts to systematically provide an overview of all the live attenuated strains that have been shown to be experimental vaccine candidates. Moreover, it aims to analyze the development of these vaccine candidates, obtained by deleting specific genes or group of genes, and their efficacy in preventing virus infection and clinical disease after being challenged with virulent isolates. This report summarizes all the experimental vaccine strains that have shown promise against the contemporary pandemic strain of African swine fever.
Topics: African Swine Fever; African Swine Fever Virus; Animals; Swine; Vaccines, Attenuated; Vaccines, Synthetic; Viral Vaccines; Viruses, Unclassified
PubMed: 35632620
DOI: 10.3390/v14050878 -
Viruses Jun 2022The conventional live smallpox vaccine based on the vaccinia virus (VACV) cannot be widely used today because it is highly reactogenic. Therefore, there is a demand for...
The conventional live smallpox vaccine based on the vaccinia virus (VACV) cannot be widely used today because it is highly reactogenic. Therefore, there is a demand for designing VACV variants possessing enhanced immunogenicity, making it possible to reduce the vaccine dose and, therefore, significantly eliminate the pathogenic effect of the VACV on the body. In this study, we analyzed the development of the humoral and T cell-mediated immune responses elicited by immunizing mice with low-dose VACV variants carrying the mutant gene (which increases production of extracellular virions) or the deleted gene (whose protein product inhibits antigen presentation by the major histocompatibility complex class II). The VACV LIVP strain, which is used as a smallpox vaccine in Russia, and its recombinant variants LIVP-A34R*, LIVP-dA35R, and LIVP-A34R*-dA35R, were compared upon intradermal immunization of BALB/c mice at a dose of 10 pfu/animal. The strongest T cell-mediated immunity was detected in mice infected with the LIVP-A34R*-dA35R virus. The parental LIVP strain induced a significantly lower antibody level compared to the strains carrying the modified and genes. Simultaneous modification of the gene and deletion of the gene in VACV LIVP synergistically enhanced the immunogenic properties of the LIVP-A34R*-dA35R virus.
Topics: Animals; Mice; Mice, Inbred BALB C; Smallpox; Smallpox Vaccine; Vaccines, Attenuated; Vaccinia; Vaccinia virus
PubMed: 35891430
DOI: 10.3390/v14071453 -
Pediatric Nephrology (Berlin, Germany) Dec 2023The use of live attenuated vaccines in patients with immunosuppressive agents is contraindicated in package inserts and guidelines in Japan and other countries. However,... (Review)
Review
The use of live attenuated vaccines in patients with immunosuppressive agents is contraindicated in package inserts and guidelines in Japan and other countries. However, patients receiving immunosuppressants have a high risk of infectious disease becoming severe, and the necessity to prevent infectious disease is high. To date, 2,091 vaccinations have been reported in 25 reports of live attenuated vaccines in people receiving immunosuppressants. Twenty-three patients (1.1%) became infected with the virus strain used in the vaccine, which was varicella virus in 21 patients. No reports have described life-threatening complications. A prospective study at the National Center for Child Health and Development conducted under certain immunological conditions (CD4 cell count ≥ 500/mm, stimulation index of lymphocyte blast transformation by phytohemagglutinin (PHA) ≥ 101.6, serum immunoglobulin G ≥ 300 mg/dL) confirmed the serological effectiveness and safety. The evidence suggests that live attenuated vaccines can be used even in combination with immunosuppressants. Further evidence must be gathered and immunological criteria investigated to determine the conditions for safe use. Depending on the results of these investigations, the wording in package inserts and guidelines may need to be revised.
Topics: Child; Humans; Immunosuppressive Agents; Vaccines, Attenuated; Prospective Studies; Immune System Diseases; Communicable Diseases
PubMed: 37076756
DOI: 10.1007/s00467-023-05969-z -
The American Journal of Tropical... Jan 2021sporozoite (PfSPZ) Vaccine (radiation-attenuated, aseptic, purified, cryopreserved PfSPZ) and PfSPZ-CVac (infectious, aseptic, purified, cryopreserved PfSPZ... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
sporozoite (PfSPZ) Vaccine (radiation-attenuated, aseptic, purified, cryopreserved PfSPZ) and PfSPZ-CVac (infectious, aseptic, purified, cryopreserved PfSPZ administered to subjects taking weekly chloroquine chemoprophylaxis) have shown vaccine efficacies (VEs) of 100% against homologous controlled human malaria infection (CHMI) in nonimmune adults. sporozoite-CVac has never been assessed against CHMI in African vaccinees. We assessed the safety, immunogenicity, and VE against homologous CHMI of three doses of 2.7 × 10 PfSPZ of PfSPZ Vaccine at 8-week intervals and three doses of 1.0 × 10 PfSPZ of PfSPZ-CVac at 4-week intervals with each arm randomized, double-blind, placebo-controlled, and conducted in parallel. There were no differences in solicited adverse events between vaccinees and normal saline controls, or between PfSPZ Vaccine and PfSPZ-CVac recipients during the 6 days after administration of investigational product. However, from days 7-13, PfSPZ-CVac recipients had significantly more AEs, probably because of Pf parasitemia. Antibody responses were 2.9 times higher in PfSPZ Vaccine recipients than PfSPZ-CVac recipients at time of CHMI. Vaccine efficacy at a median of 14 weeks after last PfSPZ-CVac dose was 55% (8 of 13, = 0.051) and at a median of 15 weeks after last PfSPZ Vaccine dose was 27% (5 of 15, = 0.32). The higher VE in PfSPZ-CVac recipients of 55% with a 27-fold lower dose was likely a result of later stage parasite maturation in the liver, leading to induction of cellular immunity against a greater quantity and broader array of antigens.
Topics: Adolescent; Adult; Aged; Animals; Antibodies, Protozoan; Antimalarials; Child; Child, Preschool; Chloroquine; Double-Blind Method; Equatorial Guinea; Female; Humans; Immunization; Immunogenicity, Vaccine; Infant; Malaria Vaccines; Malaria, Falciparum; Male; Middle Aged; Parasitemia; Plasmodium falciparum; Vaccines, Attenuated; Young Adult
PubMed: 33205741
DOI: 10.4269/ajtmh.20-0435 -
Applied Microbiology and Biotechnology Jun 2021As the reality of pandemic threats challenges humanity, exemplified during the ongoing SARS-CoV-2 infections, the development of vaccines targeting these etiological... (Review)
Review
As the reality of pandemic threats challenges humanity, exemplified during the ongoing SARS-CoV-2 infections, the development of vaccines targeting these etiological agents of disease has become increasingly critical. Of paramount concern are novel and reemerging pathogens that could trigger such events, including the plague bacterium Yersinia pestis. Y. pestis is responsible for more human deaths than any other known pathogen and exists globally in endemic regions of the world, including the four corners region and Northern California in the USA. Recent cases have been scattered throughout the world, including China and the USA, with serious outbreaks in Madagascar during 2008, 2013-2014, and, most recently, 2017-2018. This review will focus on recent advances in plague vaccine development, a seemingly necessary endeavor, as there is no Food and Drug Administration-licensed vaccine available for human distribution in western nations, and that antibiotic-resistant strains are recovered clinically or intentionally developed. Progress and recent development involving subunit, live-attenuated, and nucleic acid-based plague vaccine candidates will be discussed in this review. KEY POINTS: • Plague vaccine development remains elusive yet critical. • DNA, animal, and live-attenuated vaccine candidates gain traction.
Topics: Animals; Antibodies, Bacterial; COVID-19; China; Humans; Plague; Plague Vaccine; SARS-CoV-2; Vaccines, Attenuated; Yersinia pestis
PubMed: 34142207
DOI: 10.1007/s00253-021-11389-6 -
Journal of Virology Sep 2023African swine fever (ASF) is a highly contagious and acute hemorrhagic viral disease in domestic pigs and wild boars. Domestic pigs infected with virulent African swine...
African swine fever (ASF) is a highly contagious and acute hemorrhagic viral disease in domestic pigs and wild boars. Domestic pigs infected with virulent African swine fever virus (ASFV) isolates have a high mortality, approaching 100%. Identification of ASFV genes related to virulence/pathogenicity and deletion of them are considered to be key steps in the development of live attenuated vaccines, because the ability of ASFV to escape host innate immune responses is related to viral pathogenicity. However, the relationship between the host antiviral innate immune responses and the pathogenic genes of ASFV has not been fully understood. In this study, the ASFV H240R protein (pH240R), a capsid protein of ASFV, was found to inhibit type I interferon (IFN) production. Mechanistically, pH240R interacted with the N-terminal transmembrane domain of stimulator of interferon genes (STING) and inhibited its oligomerization and translocation from the endoplasmic reticulum to the Golgi apparatus. Additionally, pH240R inhibited the phosphorylation of interferon regulatory factor 3 (IRF3) and TANK binding kinase 1 (TBK1), leading to reduced production of type I IFN. Consistent with these results, infection with -deficient ASFV (ASFV-ΔH240R) induced more type I IFN than infection with its parental strain, ASFV HLJ/18. We also found that pH240R may enhance viral replication via inhibition of type I IFN production and the antiviral effect of interferon alpha (IFN-α). Taken together, our findings provide a new explanation for the reduction of ASFV's replication ability by knockout of the gene and a clue for the development of live attenuated ASFV vaccines. African swine fever (ASF), caused by African swine fever virus (ASFV), is a highly contagious and acute hemorrhagic viral disease with a high mortality, approaching 100% in domestic pigs. However, the relationship between viral pathogenicity and immune evasion of ASFV is not fully understood, which limits the development of safe and effective ASF vaccines, specifically, live attenuated vaccines. In this study, we found that pH240R, as a potent antagonist, inhibited type I IFN production by targeting STING and inhibiting its oligomerization and translocation from the endoplasmic reticulum to the Golgi apparatus. Furthermore, we also found that deletion of the gene reduced viral pathogenicity by enhancing type I IFN production, which decreases ASFV replication. Taken together, our findings provide a clue for the development of an ASFV live attenuated vaccine via deleting the gene.
Topics: Animals; African Swine Fever; African Swine Fever Virus; Interferon Type I; Sus scrofa; Swine; Vaccines, Attenuated; Viral Proteins
PubMed: 37199611
DOI: 10.1128/jvi.00577-23 -
Frontiers in Cellular and Infection... 2019There is an unmet public health need for a universal influenza vaccine (UIV) to provide broad and durable protection from influenza virus infections. The identification... (Review)
Review
There is an unmet public health need for a universal influenza vaccine (UIV) to provide broad and durable protection from influenza virus infections. The identification of broadly protective antibodies and cross-reactive T cells directed to influenza viral targets present a promising prospect for the development of a UIV. Multiple targets for cross-protection have been identified in the stalk and head of hemagglutinin (HA) to develop a UIV. Recently, neuraminidase (NA) has received significant attention as a critical component for increasing the breadth of protection. The HA stalk-based approaches have shown promising results of broader protection in animal studies, and their feasibility in humans are being evaluated in clinical trials. Mucosal immune responses and cross-reactive T cell immunity across influenza A and B viruses intrinsic to live attenuated influenza vaccine (LAIV) have emerged as essential features to be incorporated into a UIV. Complementing the weakness of the stand-alone approaches, prime-boost vaccination combining HA stalk, and LAIV is under clinical evaluation, with the aim to increase the efficacy and broaden the spectrum of protection. Preexisting immunity in humans established by prior exposure to influenza viruses may affect the hierarchy and magnitude of immune responses elicited by an influenza vaccine, limiting the interpretation of preclinical data based on naive animals, necessitating human challenge studies. A consensus is yet to be achieved on the spectrum of protection, efficacy, target population, and duration of protection to define a "universal" vaccine. This review discusses the recent advancements in the development of UIVs, rationales behind cross-protection and vaccine designs, and challenges faced in obtaining balanced protection potency, a wide spectrum of protection, and safety relevant to UIVs.
Topics: Antibodies, Viral; CD8-Positive T-Lymphocytes; Cross Protection; Cross Reactions; Epitopes, T-Lymphocyte; Hemagglutinin Glycoproteins, Influenza Virus; Humans; Influenza Vaccines; Influenza, Human; Neuraminidase; Vaccines, Attenuated; Vaccinology; Viral Proteins
PubMed: 31649895
DOI: 10.3389/fcimb.2019.00344 -
Frontiers in Immunology 2022Previous attempts to develop a vaccine against bovine leukemia virus (BLV) have not been successful because of inadequate or short-lived stimulation of all immunity...
Previous attempts to develop a vaccine against bovine leukemia virus (BLV) have not been successful because of inadequate or short-lived stimulation of all immunity components. In this study, we designed an approach based on an attenuated BLV provirus by deleting genes dispensable for infectivity but required for efficient replication. The ability of the vaccine to protect from natural BLV infection was investigated in the context of dairy productive conditions in an endemic region. The attenuated vaccine was tested in a farm in which the prevalence rose from 16.7% in young cattle at the beginning of the study to more than 90% in adult individuals. Sterilizing immunity was obtained in 28 out of 29 vaccinated heifers over a period of 48 months, demonstrating the effectiveness of the vaccine. As indicated by the antiviral antibody titers, the humoral response was slightly reduced compared to wild-type infection. After initial post-vaccination bursts, the proviral loads of the attenuated vaccine remained most frequently undetectable. During the first dairy cycle, proviral DNA was not detected by nested-PCR in milk samples from vaccinated cows. During the second dairy cycle, provirus was sporadically detected in milk of two vaccinated cows. Forty-two calves born from vaccinated cows were negative for proviral DNA but had antiviral antibodies in their peripheral blood. The attenuated strain was not transmitted to sentinels, further supporting the safety of the vaccine. Altogether, these data thus demonstrate that the vaccine against BLV is safe and effective in herd conditions characterized by a very high incidence. This cost-effective approach will thus decrease the prevalence of BLV without modification of production practices. After facing a series of challenges pertaining to effectiveness and biosafety, the vaccine is now available for further large-scale delivery. The different challenges and hurdles that were bypassed may be informative for the development of a vaccine against HTLV-1.
Topics: Animals; Antiviral Agents; Cattle; Enzootic Bovine Leukosis; Female; Leukemia Virus, Bovine; Proviruses; Vaccines, Attenuated
PubMed: 36032174
DOI: 10.3389/fimmu.2022.980514