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Scientific Reports Jun 2024Insect cells have long been the main expression host of many virus-like particles (VLP). VLPs resemble the respective viruses but are non-infectious. They are important...
Insect cells have long been the main expression host of many virus-like particles (VLP). VLPs resemble the respective viruses but are non-infectious. They are important in vaccine development and serve as safe model systems in virus research. Commonly, baculovirus expression vector system (BEVS) is used for VLP production. Here, we present an alternative, plasmid-based system for VLP expression, which offers distinct advantages: in contrast to BEVS, it avoids contamination by baculoviral particles and proteins, can maintain cell viability over the whole process, production of alphanodaviral particles will not be induced, and optimization of expression vectors and their ratios is simple. We compared the production of noro-, rota- and entero-VLP in the plasmid-based system to the standard process in BEVS. For noro- and entero-VLPs, similar yields could be achieved, whereas production of rota-VLP requires some further optimization. Nevertheless, in all cases, particles were formed, the expression process was simplified compared to BEVS and potential for the plasmid-based system was validated. This study demonstrates that plasmid-based transfection offers a viable option for production of noro-, rota- and entero-VLPs in insect cells.
Topics: Animals; Plasmids; Rotavirus; Norovirus; Enterovirus; Sf9 Cells; Baculoviridae; Genetic Vectors; Transfection; Vaccines, Virus-Like Particle; Insecta; Cell Line
PubMed: 38937523
DOI: 10.1038/s41598-024-65316-6 -
Vaccines Jun 2024Introducing new recombinant protein antigens to existing pediatric combination vaccines is important in improving coverage and affordability, especially in low- and...
Evaluating the Compatibility of New Recombinant Protein Antigens (Trivalent NRRV) with a Mock Pentavalent Combination Vaccine Containing Whole-Cell Pertussis: Analytical and Formulation Challenges.
Introducing new recombinant protein antigens to existing pediatric combination vaccines is important in improving coverage and affordability, especially in low- and middle-income countries (LMICs). This case-study highlights the analytical and formulation challenges encountered with three recombinant non-replicating rotavirus vaccine (NRRV) antigens (t-NRRV formulated with Alhydrogel adjuvant, AH) combined with a mock multidose formulation of a pediatric pentavalent vaccine used in LMICs. This complex formulation contained (1) vaccine antigens (i.e., whole-cell pertussis (wP), diphtheria (D), tetanus (T), (Hib), and hepatitis B (HepB), (2) a mixture of aluminum-salt adjuvants (AH and Adju-Phos, AP), and (3) a preservative (thimerosal, TH). Selective, stability-indicating competitive immunoassays were developed to monitor binding of specific mAbs to each antigen, except wP which required the setup of a mouse immunogenicity assay. Simple mixing led to the desorption of t-NRRV antigens from AH and increased degradation during storage. These deleterious effects were caused by specific antigens, AP, and TH. An AH-only pentavalent formulation mitigated t-NRRV antigen desorption; however, the Hib antigen displayed previously reported AH-induced instability. The same rank-ordering of t-NRRV antigen stability (P[8] > P[4] > P[6]) was observed in mock pentavalent formulations and with various preservatives. The lessons learned are discussed to enable future multidose, combination vaccine formulation development with new vaccine candidates.
PubMed: 38932338
DOI: 10.3390/vaccines12060609 -
Viruses Jun 2024Human rotaviruses exhibit limited tropism and replicate poorly in most cell lines. Attachment protein VP4 is a key rotavirus tropism determinant. Previous studies in...
Human rotaviruses exhibit limited tropism and replicate poorly in most cell lines. Attachment protein VP4 is a key rotavirus tropism determinant. Previous studies in which human rotaviruses were adapted to cultured cells identified mutations in VP4. However, most such studies were conducted using only a single human rotavirus genotype. In the current study, we serially passaged 50 human rotavirus clinical specimens representing five of the genotypes most frequently associated with severe human disease, each in triplicate, three to five times in primary monkey kidney cells then ten times in the MA104 monkey kidney cell line. From 13 of the 50 specimens, we obtained 25 rotavirus antigen-positive lineages representing all five genotypes, which tended to replicate more efficiently in MA104 cells at late versus early passage. We used Illumina next-generation sequencing and analysis to identify variants that arose during passage. In VP4, variants encoded 28 mutations that were conserved for all P[8] rotaviruses and 12 mutations that were conserved for all five genotypes. These findings suggest there may be a conserved mechanism of human rotavirus adaptation to MA104 cells. In the future, such a conserved adaptation mechanism could be exploited to study human rotavirus biology or efficiently manufacture vaccines.
Topics: Rotavirus; Humans; Capsid Proteins; Genotype; Mutation; Animals; Rotavirus Infections; Serial Passage; Cell Line; Virus Replication; High-Throughput Nucleotide Sequencing; Viral Tropism
PubMed: 38932271
DOI: 10.3390/v16060978 -
Viruses May 2024Rotavirus infection continues to be a significant public health problem in developing countries, despite the availability of several vaccines. The efficacy of oral... (Review)
Review
Rotavirus infection continues to be a significant public health problem in developing countries, despite the availability of several vaccines. The efficacy of oral rotavirus vaccines in young children may be affected by significant immunological differences between individuals in early life and adults. Therefore, understanding the dynamics of early-life systemic and mucosal immune responses and the factors that affect them is essential to improve the current rotavirus vaccines and develop the next generation of mucosal vaccines. This review focuses on the advances in T-cell development during early life in mice and humans, discussing how immune homeostasis and response to pathogens is established in this period compared to adults. Finally, the review explores how this knowledge of early-life T-cell immunity could be utilized to enhance current and novel rotavirus vaccines.
Topics: Rotavirus Vaccines; Humans; Rotavirus Infections; Animals; Rotavirus; T-Lymphocytes; Administration, Oral; Immunity, Mucosal; Mice
PubMed: 38932111
DOI: 10.3390/v16060818 -
Communicable Diseases Intelligence... Jun 2024This report from the Australian Rotavirus Surveillance Program describes the circulating rotavirus genotypes identified in children and adults during the period 1...
This report from the Australian Rotavirus Surveillance Program describes the circulating rotavirus genotypes identified in children and adults during the period 1 January to 31 December 2022. After two years of a lower number of stool samples received as a result of the coronavirus disease 2019 (COVID-19) pandemic, this reporting period saw the highest number of samples received since the 2017 surveillance period, with samples received from all states and territories. During this period, 1,379 faecal specimens had been referred for rotavirus G- and P- genotype analysis, of which 1,276 were confirmed as rotavirus positive. In total, 1,119/1,276 were identified as wildtype rotavirus, 155/1,276 identified as the Rotarix vaccine strain and 2/1,276 that could not be confirmed as vaccine or wildtype due to sequencing failure. Whilst G12P[8] was the dominant genotype nationally among wildtype samples (28.2%; 315/1,119), multiple genotypes were identified at similar frequencies including G9P[4] (22.3%; 249/1,119) and G2P[4] (20.3%; 227/1,119). Geographical differences in genotype distribution were observed, largely driven by outbreaks reported in some jurisdictions. Outbreaks and increased reports of rotavirus disease were reported in the Northern Territory, Queensland, and New South Wales. A small number of unusual genotypes, potentially zoonotic in nature, were identified, including: G8P[14]; G10[14]; caninelike G3P[3]; G6P[9]; and G11P[25]. Ongoing rotavirus surveillance is crucial to identify changes in genotypic patterns and to provide diagnostic laboratories with quality assurance by reporting incidences of wildtype, vaccine-like, or false positive rotavirus results.
Topics: Humans; Rotavirus Infections; Rotavirus; Australia; Genotype; Feces; Rotavirus Vaccines; Child, Preschool; Infant; Child; Adult; COVID-19; SARS-CoV-2; Adolescent; Female; Male; Disease Outbreaks; Vaccines, Attenuated; Infant, Newborn; Annual Reports as Topic; Epidemiological Monitoring; Middle Aged
PubMed: 38926653
DOI: 10.33321/cdi.2024.48.27 -
Journal of Medical Virology Jun 2024Globally, Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in children under 5 years old, with Pakistan having the highest rates of RVA-related...
Molecular characterization of rotavirus indicates predominance of G9P[4] genotype among children with acute gastroenteritis: First report after vaccine introduction in Pakistan.
Globally, Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in children under 5 years old, with Pakistan having the highest rates of RVA-related morbidity and mortality. The current study aims to determine the genetic diversity of rotavirus and evaluate the impact of Rotarix-vaccine introduction on disease epidemiology in Pakistan. A total of 4749 children, hospitalized with acute gastroenteritis between 2018 and 2020, were tested at four hospitals in Lahore and Karachi. Of the total, 19.3% (918/4749) cases were tested positive for RVA antigen, with the positivity rate varying annually (2018 = 22.7%, 2019 = 14.4%, 2020 = 20.9%). Among RVA-positive children, 66.3% were under 1 year of age. Genotyping of 662 enzyme-linked immuno sorbent assay-positive samples revealed the predominant genotype as G9P[4] (21.4%), followed by G1P[8] (18.9%), G3P[8] (11.4%), G12P[6] (8.7%), G2P[4] (5.7%), G2P[6] (4.8%), and 10.8% had mixed genotypes. Among vaccinated children, genotypes G9P[4] and G12P[6] were more frequently detected, whereas a decline in G2P[4] was observed. Phylogenetic analysis confirmed the continued circulation of indigenous genotypes detected earlier in the country except G9 and P[6] strains. Our findings highlight the predominance of G9P[4] genotype after the vaccine introduction thus emphasizing continual surveillance to monitor the disease burden, viral diversity, and their impact on control of rotavirus gastroenteritis in children.
Topics: Humans; Rotavirus; Gastroenteritis; Rotavirus Infections; Genotype; Rotavirus Vaccines; Infant; Child, Preschool; Pakistan; Female; Male; Vaccines, Attenuated; Phylogeny; Genetic Variation; Feces; Acute Disease
PubMed: 38924137
DOI: 10.1002/jmv.29761 -
Pathogens (Basel, Switzerland) Jun 2024Enteric infections due to viral pathogens are a major public health concern. Detecting the risk areas requires a strong surveillance system for pathogenic viruses in...
Enteric infections due to viral pathogens are a major public health concern. Detecting the risk areas requires a strong surveillance system for pathogenic viruses in sources such as wastewater. Towards building an environmental surveillance system in Zambia, we aimed to identify group A rotavirus (RVA) and human adenovirus (HAdV) in wastewater. Convenient sampling was conducted at four study sites every Tuesday for five consecutive weeks. The research team focused on three different methods of viral concentration to determine the suitability in terms of cost and applicability for a regular surveillance system: the bag-mediated filtration system (BMFS), polyethylene glycol-based (PEG) precipitation, and skimmed milk (SM) flocculation. We screened 20 wastewater samples for HAdV and RVA using quantitative polymerase chain reaction (qPCR) and conventional polymerase chain reaction (cPCR). Of the 20 samples tested using qPCR, 18/20 (90%) tested positive for HAdV and 14/20 (70%) tested positive for RVA. For the genetic sequencing, qPCR positives were subjected to cPCR, of which 12 positives were successfully amplified. The human adenovirus was identified with a nucleotide identity range of 98.48% to 99.53% compared with the reference genome from GenBank. The BMFS and SM flocculation were the most consistent viral concentration methods for HAdV and RVA, respectively. A statistical analysis of the positives showed that viral positivity differed by site ( < 0.001). SM and PEG may be the most appropriate options in resource-limited settings such as Zambia due to the lower costs associated with these concentration methods. The demonstration of HAdV and RVA detection in wastewater suggests the presence of the pathogens in the communities under study and the need to establish a routine wastewater surveillance system for the identification of pathogens.
PubMed: 38921784
DOI: 10.3390/pathogens13060486 -
The Pediatric Infectious Disease Journal Jun 2024In June 2022, French health authorities issued a universal recommendation for routine administration and reimbursement of rotavirus vaccines in infants. Given this...
OBJECTIVE
In June 2022, French health authorities issued a universal recommendation for routine administration and reimbursement of rotavirus vaccines in infants. Given this recent recommendation by French health authorities, we sought to understand the public health impact of a universal rotavirus vaccination strategy compared with no vaccination.
MATERIALS AND METHODS
A deterministic, age-structured, nonlinear dynamic transmission model, accounting for herd immunity, was developed. We considered 3 vaccination coverage scenarios: high (95%), medium (75%) and low (55%). Model parameter values were based on published modeling and epidemiological literature. Model outcomes included rotavirus gastroenteritis (RVGE) cases and healthcare resource utilization due to RVGE (hospitalizations, general practitioner or emergency department visits), as well as the number needed to vaccinate to prevent 1 RVGE case (mild or severe) and 1 RVGE-related hospitalization. Model calibration and analyses were conducted using Mathematica 11.3.
RESULTS
Over 5 years following implementation, RVGE cases for children under 5 years are estimated to be reduced by 84% under a high vaccination coverage scenario, by 72% under a medium vaccination coverage scenario and by 47% under a low vaccination coverage scenario. Across all scenarios, the number needed to vaccinate to avert 1 RVGE case and hospitalization varied between 1.86-2.04 and 24.15-27.44, respectively.
CONCLUSIONS
Rotavirus vaccination with high vaccination coverage in France is expected to substantially reduce the number of RVGE cases and associated healthcare resource utilization.
PubMed: 38917026
DOI: 10.1097/INF.0000000000004448 -
Future Microbiology Jun 2024The value of preventive medicine is superior to treatment with vaccinations occupying high priority. Nevertheless, heavy pressure has started to form in regard to... (Review)
Review
The value of preventive medicine is superior to treatment with vaccinations occupying high priority. Nevertheless, heavy pressure has started to form in regard to strains not included in vaccines contributing to the changing epidemiology of pathogen subtypes leading to 'vaccine-induced strain replacement'. Among other mechanisms, increasing fitness of nonvaccine strains and metabolic shifts in the subtypes have been described. Classical examples include pneumococcal infections and viral diseases, such as the human papilloma virus. Recently, it has been described in SARS-CoV-2, leading to the emergence of new subtypes, such as Omicron and Delta variants. The phenomenon has also been reported in , and rotavirus. This study addresses the concepts, examples and implications of this phenomenon.
PubMed: 38913745
DOI: 10.1080/17460913.2024.2345003 -
Acta Tropica Jun 2024Rotavirus A (RVA) is a leading cause of severe gastroenteritis in children worldwide, and vaccination has become a pivotal strategy to reduce the associated morbidity...
Rotavirus A (RVA) is a leading cause of severe gastroenteritis in children worldwide, and vaccination has become a pivotal strategy to reduce the associated morbidity and mortality. This study presents a molecular characterization of RVA genotypes circulating among vaccinated children in Pakistan during the year 2019. A total of 510 stool samples were collected from children of up to five years of age presenting with acute gastroenteritis symptoms in Rawalpindi, Islamabad regions of Pakistan. The RVA antigen was detected using ELISA on these samples. RVA G/P genotyping was performed on ELISA positive samples using Multiplex semi-nested reverse transcriptase PCR. RVA was found in 130 fecal samples, with an overall prevalence of 25.4 %. G9P[8] (20 %) is the most prevalent genotype, followed by G12P[6] (17 %), G3P[8] (14 %), G1P[8] (12 %), G2P[4] (10 %), G12P[8] (7 %), G9P[6] (7 %), G3P[6] (6 %), G3P[4] (4 %) and G1P[6] (3 %) respectively. There is a statistically significant difference (p < 0.05) found in the group age (in months) of RVA gastroenteritis cases as detected by RT-PCR. The highest number of positive cases was found in the age range from 0 to 6 months, followed by 7-12 months, 13-24 months, and 25-60 months, respectively. Dehydration is statistically significantly associated (p˂ 0.05) in RVA gastroenteritis cases compared to those who tested negative. This study emphasizes the significance of maintaining a continuous surveillance system and conducting genomic analysis of RVA genotypes in children upto the age of 5 years. This is essential for tracking the circulation of RVA genotypes. The results from this research enhance our comprehension of how RVA genotypes are changing over time in Pakistan, underscoring the ongoing necessity for improving vaccine coverage and effectiveness. This, in turn, can help reduce the impact of RVA-related illnesses in children.
PubMed: 38909724
DOI: 10.1016/j.actatropica.2024.107300