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Vaccines May 2024While two circumsporozoite protein-based pre-erythrocytic vaccines (PEV), RTS,S and R21, have been approved by the WHO, no blood-stage vaccine (BSV) or... (Review)
Review
While two circumsporozoite protein-based pre-erythrocytic vaccines (PEV), RTS,S and R21, have been approved by the WHO, no blood-stage vaccine (BSV) or transmission-blocking vaccine (TBV) has reached a phase 3 trial. One of the major obstacles that slows down malaria vaccine development is the shortage (or lack) of in vitro assays or animal models by which investigators can reasonably select the best vaccine formulation (e.g., antigen, adjuvant, or platform) and/or immunization strategy (e.g., interval of inoculation or route of immunization) before a human phase 2 trial. In the case of PEV, RTS,S and R21 have set a benchmark, and a new vaccine can be compared with (one of) the approved PEV directly in preclinical or early clinical studies. However, such an approach cannot be utilized for BSV or TBV development at this moment. The focus of this review is in vitro assays or in vivo models that can be used for BSV or TBV development, and I discuss important considerations during assay selection, standardization, qualification, validation, and interpretation of the assay results. Establishment of a robust assay/model with proper interpretation of the results is the one of key elements to accelerate future vaccine development.
PubMed: 38932315
DOI: 10.3390/vaccines12060586 -
Vaccines May 2024The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in the COVID-19 pandemic, has profoundly impacted global healthcare systems... (Review)
Review
The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in the COVID-19 pandemic, has profoundly impacted global healthcare systems and the trajectory of economic advancement. As nations grapple with the far-reaching consequences of this unprecedented health crisis, the administration of COVID-19 vaccines has proven to be a pivotal strategy in managing this crisis. Protein-based vaccines have garnered significant attention owing to their commendable safety profile and precise immune targeting advantages. Nonetheless, the unpredictable mutations and widespread transmission of SARS-CoV-2 have posed challenges for vaccine developers and governments worldwide. Monovalent and multivalent vaccines represent two strategies in COVID-19 vaccine development, with ongoing controversy surrounding their efficacy. This review concentrates on the development of protein-based COVID-19 vaccines, specifically addressing the transition from monovalent to multivalent formulations, and synthesizes data on vaccine manufacturers, antigen composition, pivotal clinical study findings, and other features that shape their distinct profiles and overall effectiveness. Our hypothesis is that multivalent vaccine strategies for COVID-19 could offer enhanced capability with broad-spectrum protection.
PubMed: 38932308
DOI: 10.3390/vaccines12060579 -
Vaccines May 2024At times of pandemics, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the situation demands rapid development and production...
At times of pandemics, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the situation demands rapid development and production timelines of safe and effective vaccines for delivering life-saving medications quickly to patients. Typical biologics production relies on using the lengthy and arduous approach of stable single-cell clones. Here, we used an alternative approach, a stable cell pool that takes only weeks to generate compared to a stable single-cell clone that needs several months to complete. We employed the membrane, envelope, and highly immunogenic spike proteins of SARS-CoV-2 to produce virus-like particles (VLPs) using the HEK293-F cell line as a host system with an economical transfection reagent. The cell pool showed the stability of protein expression for more than one month. We demonstrated that the production of SARS-CoV-2 VLPs using this cell pool was scalable up to a stirred-tank 2 L bioreactor in fed-batch mode. The purified VLPs were properly assembled, and their size was consistent with the authentic virus. Our particles were functional as they specifically entered the cell that naturally expresses ACE-2. Notably, this work reports a practical and cost-effective manufacturing platform for scalable SARS-CoV-2 VLPs production and chromatographic purification.
PubMed: 38932290
DOI: 10.3390/vaccines12060561 -
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 2024Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy...
Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy observations revealed two kinds of virus particles with the sizes of 150-210 nm and 20-30 nm, respectively. Detection of 276 fecal specimens from the diseased herds showed the extensive infection of peste des petits ruminants virus (63.77%, 176/276) and caprine enterovirus (76.81%, 212/276), with a co-infection rate of 57.97% (160/276). These results were partially validated with RT-PCR, where all five PPRV-positive and CEV-positive specimens yielded the expected size of fragments, respectively, while no fragments were amplified from PPRV-negative and CEV-negative specimens. Moreover, corresponding PPRV and CEV fragments were amplified in PPRV and CEV double-positive specimens. Histopathological examinations revealed severe microscopic lesions such as degeneration, necrosis, and detachment of epithelial cells in the bronchioles and intestine. An immunohistochemistry assay detected PPRV antigens in bronchioles, cartilage tissue, intestine, and lymph nodes. Simultaneously, caprine enterovirus antigens were detected in lung, kidney, and intestinal tissues from the goats infected by the peste des petits ruminants virus. These results demonstrated the co-infection of peste des petits ruminants virus with caprine enterovirus in goats, revealing the tissue tropism for these two viruses, thus laying a basis for the future diagnosis, prevention, and epidemiological survey for these two virus infections.
Topics: Animals; Goats; Peste-des-Petits-Ruminants; Peste-des-petits-ruminants virus; Goat Diseases; China; Coinfection; Enterovirus Infections; Diarrhea; Enterovirus; Feces; Phylogeny
PubMed: 38932277
DOI: 10.3390/v16060986 -
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 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 2024Diarrhea, often caused by viruses like rotavirus (RV) and norovirus (NV), is a global health concern. This study focuses on RV and NV in Jining City from 2021 to 2022....
Diarrhea, often caused by viruses like rotavirus (RV) and norovirus (NV), is a global health concern. This study focuses on RV and NV in Jining City from 2021 to 2022. Between 2021 and 2022, a total of 1052 diarrhea samples were collected. Real-Time Quantitative Fluorescent Reverse Transcriptase-PCR was used to detect RV-A, NV GI, and NV GII. For RV-A-positive samples, VP7 and VP4 genes were sequenced for genotype analysis, followed by the construction of evolutionary trees. Likewise, for NV-GII-positive samples, VP1 and RdRp genes were sequenced for genotypic analysis, and evolutionary trees were subsequently constructed. Between 2021 and 2022, Jining City showed varying detection ratios: RV-A alone (excluding co-infection of RV-A and NV GII) at 7.03%, NV GI at 0.10%, NV GII alone (excluding co-infection of RV-A and NV GII) at 5.42%, and co-infection of RV-A and NV GII at 1.14%. The highest RV-A ratios were shown in children ≤1 year and 2-5 years. Jining, Jinxiang County, and Liangshan County had notably high RV-A ratios at 24.37% (excluding co-infection of RV-A and NV GII) and 18.33% (excluding co-infection of RV-A and NV GII), respectively. Jining, Qufu, and Weishan had no RV-A positives. Weishan showed the highest NV GII ratios at 35.48% (excluding co-infection of RV-A and NV GII). Genotype analysis showed that, in 2021, G9P[8] and G2P[4] were dominant at 94.44% and 5.56%, respectively. In 2022, G8P[8], G9P[8], and G1P[8] were prominent at 75.86%, 13.79%, and 10.35%, respectively. In 2021, GII.3[P12], GII.4[P16], and GII.4[P31] constituted 71.42%, 14.29%, and 14.29%, respectively. In 2022, GII.3[P12] and GII.4[P16] accounted for 55.00% and 45.00%, respectively. RV-A and NV showed varying patterns for different time frames, age groups, and regions within Jining. Genotypic shifts were also observed in prevalent RV-A and NV GII strains in Jining City from 2021 to 2022. Ongoing monitoring of RV-A and NV is recommended for effective prevention and control.
Topics: Norovirus; Rotavirus; Humans; Rotavirus Infections; Genotype; Caliciviridae Infections; Child, Preschool; Infant; Phylogeny; Diarrhea; Child; China; Female; Coinfection; Gastroenteritis; Feces; Male; Adult; Adolescent; Capsid Proteins; Infant, Newborn; Young Adult; Middle Aged
PubMed: 38932216
DOI: 10.3390/v16060925 -
Viruses May 2024Bacteriophages (phages) are viruses that infect the bacteria within which their reproduction cycle takes place, a process that ends in the lysis and death of the...
Bacteriophages (phages) are viruses that infect the bacteria within which their reproduction cycle takes place, a process that ends in the lysis and death of the bacterial cell. Some phages are also able to destroy bacterial biofilms. Due to increased antibiotics resistance, , another biofilm-forming pathogen, is a problem in many parts of the world. Zinc oxide (ZnO) and other metal nanoparticles (NPs) are biologically active and also possess anti-biofilm properties. ZnO-NPs were prepared by the green synthesis method using orange peels. The vibrational peaks of the ZnO-NPs were analyzed using FTIR analysis, and their size and morphological properties were determined using scanning electron microscopy (SEM). The ability of the ZnO-NPs to reduce or eliminate biofilm alone or in combination with phages PB10 and PA19 was investigated. The cells were effectively killed in the preformed 48 h biofilms during a 24 h incubation with the ZnO-NP-phage combination, in comparison with the control or ZnO-NPs alone. The treatments on growing biofilms were most efficient in the final stages of biofilm development. All five treatment groups showed a significant biofilm reduction compared to the control group ( < 0.0001) at 48 h of incubation. The influence of the ZnO-NPs and phages on the quorum sensing system of was monitored by quantitative real-time PCR (qRT-PCR) of the autoinducer biosynthesis gene . While the ZnO-NPs repressed the gene transcription, the phages slightly activated it at 24 and 48 h of incubation. Also, the effect of the ZnO-NPs and phage PA19 on the viability of HFF2 cells was investigated and the results showed that the combination of NPs with PA19 reduced the toxic effect of ZnO-NPs and also stimulated the growth in normal cells.
Topics: Zinc Oxide; Pseudomonas aeruginosa; Biofilms; Metal Nanoparticles; Green Chemistry Technology; Bacteriophages; Anti-Bacterial Agents; Nanoparticles
PubMed: 38932188
DOI: 10.3390/v16060897 -
Viruses May 2024Congenital cytomegalovirus (cCMV) infection poses significant risks to fetal development, particularly affecting the nervous system. This study reports a fetal autopsy...
Congenital cytomegalovirus (cCMV) infection poses significant risks to fetal development, particularly affecting the nervous system. This study reports a fetal autopsy case, examining cCMV infection and focusing on CMV DNA measurements in various fetal organs before formalin fixation, a novel approach for comprehensive CMV DNA evaluations in fetal organs affected by cCMV. A 20-week-old male fetus was diagnosed with cCMV following the detection of CMV DNA in ascites obtained via abdominocentesis in utero. After the termination of pregnancy, multiple organs of the fetus, including the cerebrum, thyroid gland, heart, lungs, liver, spleen, kidneys, and adrenal glands, were extracted and examined for CMV DNA loads using a real-time polymerase chain reaction. Histopathological examination involved hematoxylin-eosin and CMV-specific immunostaining. A correlation was found between CMV DNA loads and pathology, with higher CMV-infected cell numbers observed in organs positively identified with both staining methods, exhibiting CMV DNA levels of ≥1.0 × 10 copies/mL, compared to those detected solely by CMV-specific immunostaining, where CMV DNA levels ranged from 1.0 × 10 to 1.0 × 10 copies/mL. These results highlight a quantifiable relationship between the organ infection extent and CMV DNA concentration, providing insights into cCMV pathogenesis and potentially informing future diagnostic and therapeutic strategies for cCMV infection.
Topics: Cytomegalovirus Infections; Humans; Cytomegalovirus; DNA, Viral; Viral Load; Male; Female; Fetus; Pregnancy; Adult; Autopsy; Pregnancy Complications, Infectious
PubMed: 38932183
DOI: 10.3390/v16060891