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Viruses Jun 2024Since it was first reported in 2013, the NADC30-like PRRSV has been epidemic in China. Hubei Province is known as China's key hog-exporting region. To understand the...
Since it was first reported in 2013, the NADC30-like PRRSV has been epidemic in China. Hubei Province is known as China's key hog-exporting region. To understand the prevalence and genetic variation of PRRSV, herein, we detected and analyzed 317 lung tissue samples from pigs with respiratory disease in Hubei Province, and demonstrated that the NADC30-like strain was the second-most predominant strain during 2017-2018, following the highly pathogenic PRRSV (HP-PRRSV). Additionally, we isolated a new NADC30-like PRRSV strain, named CHN-HB-2018, which could be stably passaged in Marc-145 cells. Genetic characterization analysis showed that compared with the NADC30 strain, the CHN-HB-2018 strain had several amino acid variations in glycoprotein (GP) 3, GP5, and nonstructural protein 2 (NSP2). Moreover, the CHN-HB-2018 strain showed a unique 5-amino acid (aa) deletion in NSP2, which has not previously been reported. Gene recombination analysis identified the CHN-HB-2018 strain as a potentially recombinant PRRSV of the NADC30-like strain and HP-PRRSV. Animal experiments indicated that the CHN-HB-2018 strain has a mild pathogenicity, with no mortality and only mild fever observed in piglets. This study contributes to defining the evolutionary characteristics of PRRSV and its molecular epidemiology in Hubei Province, and provides a potential candidate strain for PRRSV vaccine development.
Topics: Porcine respiratory and reproductive syndrome virus; Animals; Swine; Porcine Reproductive and Respiratory Syndrome; China; Phylogeny; Virulence; Genome, Viral; Recombination, Genetic; Genetic Variation; Lung
PubMed: 38932283
DOI: 10.3390/v16060993 -
Viruses Jun 2024Porcine reproductive and respiratory syndrome virus (PRRSV) presents a significant threat to the global swine industry. The development of highly effective subunit...
Porcine reproductive and respiratory syndrome virus (PRRSV) presents a significant threat to the global swine industry. The development of highly effective subunit nanovaccines is a promising strategy for preventing PRRSV variant infections. In this study, two different types of ferritin (Ft) nanovaccines targeting the major glycoprotein GP5, named GP5m-Ft and (Bp-IVp)-Ft, were constructed and evaluated as vaccine candidates for PRRSV. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) demonstrated that both purified GP5m-Ft and (Bp-IVp)-Ft proteins could self-assemble into nanospheres. A comparison of the immunogenicity of GP5m-Ft and (Bp-IVp)-Ft with an inactivated PRRSV vaccine in BALB/c mice revealed that mice immunized with GP5m-Ft exhibited the highest ELISA antibody levels, neutralizing antibody titers, the lymphocyte proliferation index, and IFN-γ levels. Furthermore, vaccination with the GP5m-Ft nanoparticle effectively protected piglets against a highly pathogenic PRRSV challenge. These findings suggest that GP5m-Ft is a promising vaccine candidate for controlling PRRS.
Topics: Animals; Porcine respiratory and reproductive syndrome virus; Ferritins; Mice, Inbred BALB C; Swine; Mice; Antibodies, Viral; Antibodies, Neutralizing; Nanoparticles; Porcine Reproductive and Respiratory Syndrome; Viral Vaccines; Viral Envelope Proteins; Female; Interferon-gamma; Nanovaccines
PubMed: 38932282
DOI: 10.3390/v16060991 -
Viruses Jun 2024The envelope glycoprotein (Env) of retroviruses, such as the Feline leukemia virus (FeLV), is the main target of neutralizing humoral response, and therefore, a...
The envelope glycoprotein (Env) of retroviruses, such as the Feline leukemia virus (FeLV), is the main target of neutralizing humoral response, and therefore, a promising vaccine candidate, despite its reported poor immunogenicity. The incorporation of mutations that stabilize analogous proteins from other viruses in their prefusion conformation (e.g., HIV Env, SARS-CoV-2 S, or RSV F glycoproteins) has improved their capability to induce neutralizing protective immune responses. Therefore, we have stabilized the FeLV Env protein following a strategy based on the incorporation of a disulfide bond and an Ile/Pro mutation (SOSIP) previously used to generate soluble HIV Env trimers. We have characterized this SOSIP-FeLV Env in its soluble form and as a transmembrane protein present at high density on the surface of FeLV Gag-based VLPs. Furthermore, we have tested its immunogenicity in DNA-immunization assays in C57BL/6 mice. Low anti-FeLV Env responses were detected in SOSIP-FeLV soluble protein-immunized animals; however, unexpectedly no responses were detected in the animals immunized with SOSIP-FeLV Gag-based VLPs. In contrast, high humoral response against FeLV Gag was observed in the animals immunized with control Gag VLPs lacking SOSIP-FeLV Env, while this response was significantly impaired when the VLPs incorporated SOSIP-FeLV Env. Our data suggest that FeLV Env can be stabilized as a soluble protein and can be expressed in high-density VLPs. However, when formulated as a DNA vaccine, SOSIP-FeLV Env remains poorly immunogenic, a limitation that must be overcome to develop an effective FeLV vaccine.
Topics: Animals; Mice; Antibodies, Viral; Antibodies, Neutralizing; Mice, Inbred C57BL; Viral Envelope Proteins; Leukemia Virus, Feline; Gene Products, gag; Female; Vaccines, Virus-Like Particle; Humans; Cats; Viral Vaccines; Immunogenicity, Vaccine
PubMed: 38932278
DOI: 10.3390/v16060987 -
Viruses Jun 2024Cervical cancer, along with other sexual and reproductive health and rights (SRHR) conditions, poses a significant burden in the Kingdom of Saudi Arabia (KSA). Despite...
Cervical cancer, along with other sexual and reproductive health and rights (SRHR) conditions, poses a significant burden in the Kingdom of Saudi Arabia (KSA). Despite the availability of effective preventive methods such as vaccinations, particularly against the Human Papillomavirus (HPV), awareness about such preventive methods and HPV vaccination remains alarmingly low in the KSA, even with governmental effort and support. While many women are aware of the risks, the uptake of the HPV vaccine remains below 10% (7.6%) at the country level. This highlights the urgent need for Knowledge, Attitude, and Practice (KAP) at the community level to raise awareness, dispel misconceptions, and empower women to embrace vaccinations. Additionally, there is a need to revitalize the cancer registry system to better track and monitor cervical cancer cases. This short communication aims to map these barriers while identifying opportunities for impactful research. Drawing from the scientific literature, government reports, and expert insights, we highlight the challenges surrounding the tackling of HPV. By exploring diverse sources of knowledge, this paper not only highlights current obstacles but also proposes actionable solutions for future interventions.
Topics: Humans; Uterine Cervical Neoplasms; Papillomavirus Vaccines; Female; Papillomavirus Infections; Saudi Arabia; Health Knowledge, Attitudes, Practice; Vaccination; Patient Acceptance of Health Care; Papillomaviridae
PubMed: 38932266
DOI: 10.3390/v16060974 -
Viruses Jun 2024Pathogenic adenovirus (Ad) infections are widespread but typically mild and transient, except in the immunocompromised. As vectors for gene therapy, vaccine, and... (Review)
Review
Pathogenic adenovirus (Ad) infections are widespread but typically mild and transient, except in the immunocompromised. As vectors for gene therapy, vaccine, and oncology applications, Ad-based platforms offer advantages, including ease of genetic manipulation, scale of production, and well-established safety profiles, making them attractive tools for therapeutic development. However, the immune system often poses a significant challenge that must be overcome for adenovirus-based therapies to be truly efficacious. Both pre-existing anti-Ad immunity in the population as well as the rapid development of an immune response against engineered adenoviral vectors can have detrimental effects on the downstream impact of an adenovirus-based therapeutic. This review focuses on the different challenges posed, including pre-existing natural immunity and anti-vector immunity induced by a therapeutic, in the context of innate and adaptive immune responses. We summarise different approaches developed with the aim of tackling these problems, as well as their outcomes and potential future applications.
Topics: Humans; Adenoviridae; Genetic Vectors; Genetic Therapy; Adaptive Immunity; Animals; Immunity, Innate; Immune System; Adenoviridae Infections
PubMed: 38932265
DOI: 10.3390/v16060973 -
Viruses Jun 2024Recently, a multiplex PCR-based titration (MPBT) assay was developed for simultaneous determination of infectious titers of all three Sabin strains of the oral...
Recently, a multiplex PCR-based titration (MPBT) assay was developed for simultaneous determination of infectious titers of all three Sabin strains of the oral poliovirus vaccine (OPV) to replace the conventional CCID assay, which is both time-consuming and laborious. The MPBT assay was shown to be reproducible, robust and sensitive. The conventional and MPBT assays showed similar results and sensitivity. The MPBT assay can be completed in two to three days, instead of ten days for the conventional assay. To prevent attenuated vaccine strains of poliovirus from reversion to virulence, a novel, genetically stable OPV (nOPV) was developed by modifying the genomes of conventional Sabin strains used in OPV. In this work, we evaluated the MPBT assay as a rapid screening tool to support trivalent nOPV (tnOPV) formulation development by simultaneous titration of the three nOPV strains to confirm stability as needed, for the selection of the lead tnOPV formulation candidate. We first assessed the ability of the MPBT assay to discriminate a 0.5 log titer difference by titrating the two tnOPV samples (undiluted and threefold-diluted) on the same plate. Once the assay was shown to be discriminating, we then tested different formulations of tnOPV drug products (DPs) that were subjected to different exposure times at 37 °C (untreated group and treated groups: 2 and 7 days at 37 °C), and to three freeze and thaw (FT) cycles. Final confirmation of the down selected formulation candidates was achieved by performing the conventional CCID assay, comparing the stability of untreated and treated groups and FT stability testing on the top three candidates. The results showed that the MPBT assay generates similar titers as the conventional assay. By testing two trivalent samples in the same plate, the assay can differentiate a 0.5 log difference between the titers of the tested nOPV samples. Also, the assay was able to detect the gradual degradation of nOPV viruses with different formulation compositions and under different time/temperature conditions and freeze/thaw cycles. We found that there were three tnOPV formulations which met the stability criteria of less than 0.5 log loss after 2 days' exposure to 37 ℃ and after three FT cycles, maintaining the potency of all three serotypes in these formulations. The ability of the MPBT assay to titrate two tnOPV lots (six viruses) in the same plate makes it cheaper and gives it a higher throughput for rapid screening. The assay detected the gradual degradation of the tnOPV and was successful in the selection of optimal formulations for the tnOPV. The results demonstrated that the MPBT method can be used as a stability indicating assay to assess the thermal stability of the nOPV. It can be used for rapid virus titer determination during the vaccine manufacturing process, and in clinical trials. The MPBT assay can be automated and applied for other viruses, including those with no cytopathic effect.
Topics: Poliovirus Vaccine, Oral; Poliovirus; Humans; Multiplex Polymerase Chain Reaction; Poliomyelitis; Vaccines, Attenuated; Reproducibility of Results; Sensitivity and Specificity
PubMed: 38932253
DOI: 10.3390/v16060961 -
Viruses Jun 2024Recently, respiratory syncytial virus (RSV) vaccines based on the prefusion F (pre-F) antigen were approved in the United States. We aimed to develop an enzyme-linked...
Recently, respiratory syncytial virus (RSV) vaccines based on the prefusion F (pre-F) antigen were approved in the United States. We aimed to develop an enzyme-linked immunosorbent assay (ELISA)-based protocol for the practical and large-scale evaluation of RSV vaccines. Two modified pre-F proteins (DS-Cav1 and SC-TM) were produced by genetic recombination and replication using an adenoviral vector. The protocol was established by optimizing the concentrations of the coating antigen (pre-F proteins), secondary antibodies, and blocking buffer. To validate the protocol, we examined its accuracy, precision, and specificity using serum samples from 150 participants across various age groups and the standard serum provided by the National Institute of Health. In the linear correlation analysis, coating concentrations of 5 and 2.5 μg/mL of DS-Cav1 and SC-TM showed high coefficients of determination (r > 0.90), respectively. Concentrations of secondary antibodies (alkaline phosphatase-conjugated anti-human immunoglobulin G, diluted 1:2000) and blocking reagents (5% skim milk/PBS-T) were optimized to minimize non-specific reactions. High accuracy was observed for DS-Cav1 (r = 0.90) and SC-TM (r = 0.86). Further, both antigens showed high precision (coefficient of variation < 15%). Inhibition ELISA revealed cross-reactivity of antibodies against DS-Cav1 and SC-TM, but not with the attachment (G) protein.
Topics: Enzyme-Linked Immunosorbent Assay; Humans; Respiratory Syncytial Virus Infections; Antibodies, Viral; Respiratory Syncytial Virus Vaccines; Respiratory Syncytial Virus, Human; Infant; Child, Preschool; Adult; Child; Adolescent; Middle Aged; Young Adult; Female; Sensitivity and Specificity; Antigens, Viral; Male; Viral Fusion Proteins; Aged
PubMed: 38932244
DOI: 10.3390/v16060952 -
Viruses Jun 2024The thermostability of vaccines, particularly enveloped viral vectored vaccines, remains a challenge to their delivery wherever needed. The freeze-drying of viral...
The thermostability of vaccines, particularly enveloped viral vectored vaccines, remains a challenge to their delivery wherever needed. The freeze-drying of viral vectored vaccines is a promising approach but remains challenging due to the water removal process from the outer and inner parts of the virus. In the case of enveloped viruses, freeze-drying induces increased stress on the envelope, which often leads to the inactivation of the virus. In this study, we designed a method to freeze-dry a recombinant vesicular stomatitis virus (VSV) expressing the SARS-CoV-2 spike glycoprotein. Since the envelope of VSV is composed of 50% lipids and 50% protein, the formulation study focused on both the protein and lipid portions of the vector. Formulations were prepared primarily using sucrose, trehalose, and sorbitol as cryoprotectants; mannitol as a lyoprotectant; and histidine as a buffer. Initially, the infectivity of rVSV-SARS-CoV-2 and the cake stability were investigated at different final moisture content levels. High recovery of the infectious viral titer (~0.5 to 1 log loss) was found at 3-6% moisture content, with no deterioration in the freeze-dried cakes. To further minimize infectious viral titer loss, the composition and concentration of the excipients were studied. An increase from 5 to 10% in both the cryoprotectants and lyoprotectant, together with the addition of 0.5% gelatin, resulted in the improved recovery of the infectious virus titer and stable cake formation. Moreover, the secondary drying temperature of the freeze-drying process showed a significant impact on the infectivity of rVSV-SARS-CoV-2. The infectivity of the vector declined drastically when the temperature was raised above 20 °C. Throughout a long-term stability study, formulations containing 10% sugar (sucrose/trehalose), 10% mannitol, 0.5% gelatin, and 10 mM histidine showed satisfactory stability for six months at 2-8 °C. The development of this freeze-drying process and the optimized formulation minimize the need for a costly cold chain distribution system.
Topics: Freeze Drying; SARS-CoV-2; COVID-19 Vaccines; Spike Glycoprotein, Coronavirus; Cryoprotective Agents; Trehalose; COVID-19; Animals; Humans; Mannitol; Sucrose; Vero Cells; Chlorocebus aethiops; Sorbitol; Drug Stability; Histidine; Vesicular stomatitis Indiana virus; Vaccines, Synthetic
PubMed: 38932234
DOI: 10.3390/v16060942 -
Viruses Jun 2024Recombination is a pervasive phenomenon in RNA viruses and an important strategy for accelerating the evolution of RNA virus populations. Recombination in the porcine... (Review)
Review
Recombination is a pervasive phenomenon in RNA viruses and an important strategy for accelerating the evolution of RNA virus populations. Recombination in the porcine reproductive and respiratory syndrome virus (PRRSV) was first reported in 1999, and many case reports have been published in recent years. In this review, all the existing reports on PRRSV recombination events were collected, and the genotypes, parental strains, and locations of the recombination breakpoints have been summarized and analyzed. The results showed that the recombination pattern constantly changes; whether inter- or intra-lineage recombination, the recombination hotspots vary in different recombination patterns. The virulence of recombinant PRRSVs was higher than that of the parental strains, and the emergence of virulence reversion was caused by recombination after using MLV vaccines. This could be attributed to the enhanced adaptability of recombinant PRRSV for entry and replication, facilitating their rapid propagation. The aim of this paper was to identify common features of recombinant PRRSV strains, reduce the recombination risk, and provide a foundation for future research into the mechanism of PRRSV recombination.
Topics: Porcine respiratory and reproductive syndrome virus; Recombination, Genetic; Animals; Swine; Porcine Reproductive and Respiratory Syndrome; Genotype; Virulence; Genome, Viral; Virus Replication; Phylogeny
PubMed: 38932221
DOI: 10.3390/v16060929 -
Viruses Jun 2024African swine fever (ASF) is a contagious viral disease affecting pigs and wild boars. It typically presents as a hemorrhagic fever but can also manifest in various... (Review)
Review
African swine fever (ASF) is a contagious viral disease affecting pigs and wild boars. It typically presents as a hemorrhagic fever but can also manifest in various forms, ranging from acute to asymptomatic. ASF has spread extensively globally, significantly impacting the swine industry. The complex and highly variable character of the ASFV genome makes vaccine development and disease surveillance extremely difficult. The overall trend in ASFV evolution is towards decreased virulence and increased transmissibility. Factors such as gene mutation, viral recombination, and the strain-specificity of virulence-associated genes facilitate viral variations. This review deeply discusses the influence of these factors on viral immune evasion, pathogenicity, and the ensuing complexities encountered in vaccine development, disease detection, and surveillance. The ultimate goal of this review is to thoroughly explore the genetic evolution patterns and variation mechanisms of ASFV, providing a theoretical foundation for advancement in vaccine and diagnostic technologies.
Topics: African Swine Fever Virus; Animals; Swine; African Swine Fever; Genetic Variation; Genome, Viral; Virulence; Viral Vaccines; Evolution, Molecular; Immune Evasion; Mutation; Vaccine Development
PubMed: 38932205
DOI: 10.3390/v16060913