Associations between Histo-Blood Group Antigen Status in Mother-Infant Dyads and Infant Oral Rotavirus Vaccine Immunogenicity in rural Zimbabwe.

INTRODUCTION: Histo-blood group antigen (HBGA) phenotypes may contribute to poor oral rotavirus vaccine (RVV) immunogenicity, since rotavirus binds intestinal epithelial HBGA glycans, while maternal HBGA status shapes breastmilk composition, which influences the composition of the infant microbiome. We investigated associations between maternal/infant HBGA phenotypes and RVV immunogenicity in rural Zimbabwe. METHODS: We undertook salivary FUT2/FUT3 phenotyping in mother-infant pairs. Serum anti-rotavirus IgA was measured by ELISA. We explored adjusted associations between FUT2/FUT3 status and RVV seroconversion (primary outcome, N=322), and seropositivity and geometric mean titre (secondary outcomes, N=776). RESULTS: Infants of FUT2-positive or FUT3-positive women were less likely to seroconvert post-RVV than infants of FUT2-negative or FUT3-negative women (FUT2-positive 20.1% versus FUT2-negative 27.5%, adjusted relative risk (aRR) 0.47, 95%CI 0.26, 0.82; P=0.008; FUT3-positive 18.1% versus FUT3-negative 30.0%, aRR 0.45, 95%CI 0.25, 0.78; P=0.005). Compared to FUT2-positive infants with FUT2-positive mothers, FUT2-positive infants with FUT2-negative mothers were twice as likely to seroconvert (36.8% versus 21.9%, aRR 2.12, 95%CI 1.23, 3.63; P=0.006). Compared to FUT3-positive infants with FUT3-positive mothers, FUT3-positive infants with FUT3-negative mothers were three times as likely to seroconvert (48.3% versus 18.2%, aRR 2.99, 95%CI 1.82, 4.90; P<0.001). CONCLUSIONS: Maternal and infant FUT2 and FUT3 status influences infant RVV immunogenicity.

Unusual BA222-like strains of Rotavirus A (Sedoreoviridae: Rotavirus: Rotavirus A): molecular and genetic analysis based on all genome segments.

INTRODUCTION: Rotavirus infection is the major cause of severe dehydrating diarrhea requiring hospitalization in young children worldwide. Due to their segmented genome, rotaviruses are capable of gene reassortment, which makes the emergence and spread of genetically novel strains possible. The purpose of this study was to search for unusual rotaviruses circulating in Nizhny Novgorod in 2021‒2023 and their molecular genetic characterization based on all genome segments. MATERIALS AND METHODS: Rotavirus-positive stool samples of children were examined by PCR genotyping and electrophoresis in PAAG. cDNA fragments of each of the 11 genes (VP1‒VP4, VP6, VP7, NSP1‒NSP5), 570 to 850 nucleotide pairs in length were sequenced for the selected strains. The phylogenetic analysis was performed in the MEGA X program. RESULTS: In the study period 2021‒2023, 11 G[P] combinations with a predominance of G3P[8] (59.5%) were identified. Six atypical Rotavirus А (RVA) strains were identified: 2 strains of the G2P[4] genotype (G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E2-H3, G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E3-H2) and 4 G3P[9] strains (all strains had the genotype G3-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3). Phylogenetic analysis based on all genes showed an evolutionary relationship between rotaviruses similar to rotaviruses of cats and dogs (BA222-like) and unusual strains of the G2P[4] genotype, for which a mixed combination of genotypes was identified and characterized for the first time. DISCUSSION: The results obtained expand the understanding of the diversity of reassortant RVAs, as well as complement the data on the genotypic structure of the rotavirus population in Nizhny Novgorod. CONCLUSION: The wide genetic diversity of reassortant RVA can help rotaviruses overcome the immunological pressure provided by natural and vaccine-induced immunity. In this regard, to control the emergence of new variants and assess changes in the virulence of rotaviruses after reassortment processes, continuous molecular monitoring for circulating RVA is necessary.

A Double Lysis Method for Animal Rotavirus RNA Extraction From Stool Samples.

Globally, porcine rotavirus is a leading cause of gastroenteritis in nursing and post-weaning piglets, as well as adult pigs. Between February 2015 and June 2016, 156 fecal samples were collected from pigs in the Northeastern part of Accra, Ghana, and screened for Group A rotavirus using the ProflowTM Kit. Here, we describe different extraction methods that were employed to recover high-quality RNA for downstream analysis, with emphasis on a novel hybrid extraction method. The hybrid approach with a kit and manual extraction method led to a 10-fold greater RNA yield versus the kit-based method alone. The new extraction method gave an average purity ratio (A260/A280) of 1.8, which was also significantly higher than that obtained solely from the manual or kit-based extraction methods. Our novel hybrid approach will be useful in the extraction of rotavirus from animal fecal samples, thus improving the yield of RNA for downstream analysis. © 2024 Wiley Periodicals LLC. Basic Protocol: Hybrid 2: A double lysis method for RNA extraction from animal stool samples Support Protocol 1: The GenElute extraction method Support Protocol 2: Hybrid 1 extraction method.

Frequency and genotyping of group A rotavirus among Egyptian children with acute gastroenteritis: a hospital-based cross-sectional study.

BACKGROUND: This hospital-based cross-sectional study aims to investigate the epidemiologic and clinical characteristics of rotavirus group A (RVA) infection among children with acute gastroenteritis and to detect the most common G and P genotypes in Egypt. METHODS: A total of 92 stool samples were collected from children under five who were diagnosed with acute gastroenteritis. RVA in stool samples was identified using ELISA and nested RT-PCR. Common G and P genotypes were identified utilizing multiplex nested RT-PCR assays. RESULTS: RVA was detected at a rate of 24% (22 /92) using ELISA and 26.1% (24 /92) using VP6 nested RT-PCR. The ELISA test demonstrated diagnostic sensitivity, specificity, and accuracy of 91.7%, 100%, and 97.8%, respectively. G3 was the most prevalent G type (37.5%), followed by G1 (12.5%), whereas the most commonly detected P type were P[8] (41.7%) and P[6] (8.2%). RVA-positive samples were significantly associated with younger aged children (p = 0.026), and bottle-fed (p = 0.033) children. In addition, RVA-positive samples were more common during cooler seasons (p = 0.0001). Children with rotaviral gastroenteritis had significantly more frequent episodes of diarrhea (10.87 ± 3.63 times/day) and vomiting (8.79 ± 3.57 times/day) per day (p = 0.013 and p = 0.011, respectively). Moreover, they had a more severe Vesikari clinical score (p = 0.049). CONCLUSION: RVA is a prevalent cause of acute gastroenteritis among Egyptian children in our locality. The discovery of various RVA genotypes in the local population, as well as the identification of common G and P untypeable strains, highlights the significance of implementing the rotavirus vaccine in Egyptian national immunization programs accompanied by continuous monitoring of strains.

Genomic analysis of an acute gastroenteritis outbreak caused by rotavirus C in Hebei, China.

Rotavirus group C is an important cause of sporadic cases and outbreaks of gastroenteritis worldwide. Whole-Genome sequences of human rotavirus C (RVC) in public databases are limited. We performed genome sequencing to analyze a RVC outbreak of acute gastroenteritis in China. Samples from 22 patients were screened for pathogens using RT-PCR, and six samples were positive for rotavirus. Whole-Genome sequencing analysis showed that the outbreak strain SJZ217 belongs to the G4-P[2]-I2-R2-C2-M3-A2-N2-T2-E2-H2 genotype and shares almost identical genomic sequences with Chungnam isolated in Korea. Phylogenetic analysis revealed strain SJZ217 also fell into a cluster with rotavirus C strains from Japan and Europe. Reassortment in the VP4 fragment was observed. These results helped to understand the genetic diversity and possible spread of RVC strains.

A rapid visualization method for detecting rotavirus A by combining nuclear acid sequence-based amplification with the CRISPR-Cas12a assay.

Introduction. Rotavirus A is the most common pathogen causing diarrhoea in children less than 5 years, leading to severe complications such as dehydration, electrolyte imbalances, acidosis, myocarditis, convulsions, pneumonia, and other life-threatening conditions.Gap statement. There is an urgent need for a rapid and efficient nucleic acid detection strategy to enable early diagnosis and treatment, preventing rotavirus transmission and associated complications.Aim. This article aimed to develop a nuclear acid sequence-based amplification (NASBA)-Cas12a system for detecting rotavirus A using fluorescence intensity or lateral flow strips.Methodology. The NASBA technology was combined with the clustered regularly interspaced short palindromic repeats-Cas12a system to establish a NASBA-Cas12a system for detecting rotavirus A.Results. The NASBA-Cas12a system could detect rotavirus A at 37 ℃ within 70 min and had no cross-reactivity with other viruses, achieving a limit of detection of 1.2 copies µl-1. This system demonstrated a sensitivity of 100%, specificity of 90%, positive predictive value of 97.22% and negative predictive value of 100%. The kappa value was 0.933, indicating that the NASBA-Cas12a system was highly consistent with reverse transcription-PCR.Conclusion. The NASBA-Cas12a system exhibited high sensitivity and specificity for detecting rotavirus A, showing great potential for clinical application.

Has Ghana's Rotavirus Vaccine Switch Met Programmatic Expectations? An Analysis of National Surveillance Data; 2018-2022.

Background: Ghana introduced a 2-dose schedule rotavirus vaccine, Rotarix, into childhood immunization in 2012 but switched to a 3-dose schedule vaccine, Rotavac, in 2020 on account of programmatic advantages offered by the latter, including lower cost per fully immunized child and lower cold chain volume requirement. The objective of the study was to assess the effect of the vaccine switch on the trends of rotavirus vaccine uptake and health facility outpatient department (OPD) attendance due to diarrhea among children aged 1-11 months. Methods: A retrospective analysis was conducted on childhood immunization and diarrhea surveillance data for 2018-2022. The uptake of the different rotavirus vaccine products and the proportion of health facility OPD attendance attributed to diarrhea, respectively, were compared between the pre- and postswitch study periods. Results: The uptake of rotavirus vaccine was sustained following the switch. There were no significant differences in vaccination coverages (rota1, Rotarix coverage [94.3%], vs rota1, Rotavac coverage [95.3%]; P = .757; rota2, Rotarix coverage [91.3%], vs rota2, Rotavac coverage [92.7%]; P = .789). The proportions of health facility OPD attendance due to diarrhea were comparable (preswitch [12.4%] vs postswitch [12.1%]; P = .838). Conclusions: Ghana's rotavirus vaccine switch yielded expected programmatic benefits without any untoward effects. The trends of vaccine uptake and reduction in diarrhea morbidity were sustained. These experiences and lessons from the rotavirus vaccine switch are vital for potential switches for other vaccines in the current immunization schedule to mitigate the annual vaccine expenditure.

Avian deltacoronaviruses encode fusion-associated small transmembrane proteins that can induce syncytia formation.

Fusion-associated small transmembrane (FAST) proteins are nonstructural viral proteins that induce cell-cell fusion. FAST proteins, which previously were identified in the genomes of double-stranded RNA viruses, typically contain an acylated N-terminal ectodomain, central transmembrane domain, and C-terminal endodomain with a polybasic region. Using sequence homology and protein motif prediction, we identified accessory proteins in a subset of avian deltacoronaviruses as putative FAST proteins. Transient expression of thrush coronavirus NS7b or common moorhen coronavirus NS7a, but not night heron coronavirus NS7b, induced cell-cell fusion. Syncytia were detected in primate kidney epithelial cells or fibroblasts but not chicken embryo fibroblasts, and addition of an N-terminal FLAG peptide to the proteins ablated fusion activity. These findings suggest that multiple avian deltacoronaviruses, positive-sense RNA viruses, encode nonstructural proteins that can mediate cell-cell fusion and share features with known FAST proteins. Additional studies are needed to understand contributions of these proteins to deltacoronavirus biology.

Potential impact of rotavirus vaccine introduction in India's Universal Immunisation Programme on private sector vaccine utilisation: an interrupted time series analysis.

BACKGROUND: Despite free immunisation services through the Universal Immunisation Programme (UIP), around 14% of Indian households seek immunisation in the private sector. We examined the potential impact of rotavirus vaccine (RVV) introduction in the Universal Immunisation Programme (UIP) on private-sector rotavirus vaccine utilisation. METHODS: We analysed nationally representative private-sector vaccine sales data. The intervention under consideration is RVV introduction in the UIP in selected Indian states. The outcome is the 'monthly RVV sales volume'-a proxy for vaccine utilisation. We performed a Poisson regression interrupted time series analysis to detect the pre-intervention trend, post-intervention level change and trend change relative to the pre-intervention for monthly rotavirus vaccine utilisation. RESULTS: Poisson segmented regression analysis showed that immediately after RVV introduction in the UIP private-sector RVV sales showed a decline in Rajasthan by 37.4% (Incidence Risk Ratio (IRR): 0.626; 95% CI: 0.504-0.779), in Tamil Nadu by 26% (IRR: 0.740; 95% CI: 0.513-1.068), in Uttar Pradesh-East by 72.2% (IRR: 0.278; 95% CI: 0.178-0.436) and in Kerala by 3% (IRR: 0.970; 95% CI: 0.651-1.447). Rajasthan, Tamil Nadu and Kerala had sustained reduction in the postintervention trend relative to the preintervention trend by 20.1% (IRR: 0.799; 95% CI: 0.763-0.836), 6.4% (IRR: 0.936; 95% CI: 0.906-0.967) and 3.3% (IRR: 0.967; 95% CI: 0.926-0.960) per month, respectively. However, in Haryana and UP-west, in the first-month post-UIP introduction, the private-sector RVV sales increased by 101% and 3.8%, respectively which was followed by a sustained decrease of 14.2% (IRR: 0.858; 95% CI: 0.688-1.070) and 5.8% (IRR: 0.942; 95% CI: 0.926-0.960) per month, respectively. In terms of long-term impact, the private sector RVV sales post-UIP introduction decreased at a monthly rate of 4.4% (IRR: 0.956, 95% CI: 0.939-0.974) in Rajasthan but increased by 5.5% (IRR: 1.055; 95% CI: 1.040-1.070) in UP-east, 0.3% (IRR: 1.003, 95% CI: 0.976-1.031)) in Kerala and 0.2% (IRR: 1.002, 95% CI: 0.993-1.011) in Tamil Nadu whereas Haryana and UP-west had a reduction in RVV utilisation by 2.8% (IRR: 0.972; 95% CI: 0.955-0.990) and 1% (IRR: 0.990; 95% CI: 0.982-0.998), respectively. CONCLUSIONS: The study provides evidence that access to RVV through UIP leads to a reduction in private-sector RVV utilisation. We recommend strengthening UIP to expand the basket of new vaccines.

CRISPR/Cas12 System-Based Assay for Rapid, Sensitive Detection of Rotavirus in Food Samples.

Foodborne viruses have become an important threat to food safety and human health. Among the foodborne viruses, group A rotavirus is the most important pathogen of diarrhea in autumn and winter. The field detection of rotavirus is crucial for the early control of infection and patient management. Quantitative real-time reverse transcription-polymerase chain reaction is the most widely used in virus detection. However, the technique relies on high-cost instruments and trained personnel, which limit its use in field detection. In this study, we developed accurate, realizable, and simple detection methods by combining optimized CRISPR (clustered regularly interspaced short palindromic repeats) Cas12 and reverse transcription loop-mediated isothermal amplification (RT-LAMP) (reverse transcription loop-mediated isothermal amplification) to reduce the requirements for temperature control and costly real-time fluorescence polymerase chain reaction instruments. We investigated two nucleic acid detection systems combining RT-LAMP with CRISPR Cas12a and RT-LAMP with CRISPR Cas12b and compared them with reverse transcription-quantitative polymerase chain reaction. The resulting detection system only needs a reaction temperature and in single tube to react for 60 min with the detection sensitivity of 38 copies/µL. Overall, this study developed an innovative method for the rapid detection of rotavirus in food samples, which will help to effectively identify food contaminated by pathogens and prevent human infections and economic losses caused by disease outbreaks.

In vitro inhibitory effect of berberine against rotavirus combined with its antioxidant, anti-inflammatory, and cytotoxicity activities.

Although berberine (BBR) is well known as a traditional medicine used in treatment of gastrointestinal diseases, its potent against viral gastroenteritis has not been specifically reported. This study aims to investigate the antiviral activity of BBR against rotavirus and evaluate its cytotoxicity and pharmacological efficacies, including antioxidant and anti-inflammatory activities in vitro. Using ultraviolet-visible absorption spectroscopy, the saturation concentration of BBR was determined as 2261 µg/mL, indicating that BBR is a poor water-soluble compound. The inhibition rate of NO production of BBR solution at a concentration of 238 µg/mL was similar to that of Cardamonin 0.3 µM with a cell viability of 92,46±0.35%, revealing the anti-inflammatory activity of BBR. The cytotoxicity of BBR solution depended on its concentration, whereby the 50% cytotoxicity concentration (CC50) of BBR after 96 h exposure was 664 µg/mL. Investigation of cytopathic effects (CPE) of MA104 cells treated with BBR and BBR-incubated rotavirus indicates that BBR could effectively inhibit the replication of rotavirus. CPEs were not observed in the cells inoculated with rotavirus (100TCID50) which was pre-incubated with BBR for 96 hours at BBR concentration of 283 µg/mL. Therefore, the study provides reliable results to demonstrate the ability of BBR to inhibit the replication of rotavirus.

Isolation and identification of BRV G6P[1] strain in Heilongjiang province, Northeast China.

Bovine rotavirus (BRV) is the main cause of acute gastroenteritis in calves, resulting in significant economic losses to the cattle industry worldwide. Additionally, BRV has multiple genotypes, which could enable cross-species transmission, thereby posing a significant risk to public health. However, there is a problem of multiple genotypes coexisting in BRV, and the cross-protection effect between different genotypes of rotavirus strains is not effective enough. Therefore, mastering clinical epidemic genotypes and using epidemic genotype strains for vaccine preparation is an effective means of preventing and controlling BRV. In this study, BRV strain DQ2020 in MA104 cells was identified by transmission electron microscopy (TEM), reverse transcription polymerase chain reaction (RT-PCR), and colloidal gold immunochromatographic test strips. The whole genome of BRV strain DQ2020 was sequenced and pathogenicity in suckling mice was assessed. The results showed that after 10 passages in MA104 cells, BRV strain DQ2020 induced cytopathic effects. Wheel-shaped virus particles (diameter, ~80 nm) were observed by TEM. A target band of 382 bp was detected by RT-PCR, a positive band was detected with the colloidal gold immunochromatographic test strips, and significant green fluorescence was observed by indirect immunofluorescence (IFA). The highest median tissue culture infectious dose of strain DQ2020 after 9 passages in MA104 cells was 10-4.81 viral particles/0.1 mL. Based on phylogenetic analysis of 11 gene fragments, the genotype of BRV strain DQ2020 was G6-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3, confirming transmission of the G6-P[1] genotype in Chinese cattle herds. Further analysis showed that the isolated strain was a reassortant of bovine (VP7, VP6, NSP3, and NSP5), human (VP4, VP1, VP2, VP3, NSP2, and NSP4), and ovine (NSP1) rotaviruses. BRV strain DQ2020 caused damage to the intestinal villi of suckling mice and diarrhea, confirming pathogenicity. In summary, this study identified a reassortant strain of bovine, human, and ovine rotavirus that is pathogenic to lactating mice, and conducted whole genome sequence analysis, providing valuable insights for the genetic evolution of the virus and the development of vaccines.

Isolation, Genomic Characterization and Evolution of Six Porcine Rotavirus A Strains in a Pig Farming Group.

Porcine rotavirus (PoRV) is a significant enteric pathogen causing gastroenteritis in piglets, which causes huge economic loss to the Chinese pig industry. In this study, six porcine rotavirus A strains were isolated from three adjacent sow farms belonging to the same company within one year, which suffered severe diarrhea outbreaks. AHBZ2303 (G11P[7]) and AHBZ2305 (G9P[23]), AHBZ2304 (G9P[23]) and AHBZ2312 (G4P[6]), AHBZ2310 (G9P[23]) and AHBZ2402 (G5P[23]) were isolated from Farm A, B and C, respectively. All six isolates were related to human rotavirus through complete genome analysis, suggesting the potential cross-species infection between humans and pigs. Evolutionary analysis revealed that AHBZ2303 and AHBZ2304 likely emerged simultaneously in Farm A and B, and then AHBZ2304 was introduced to Farm A and C, leading to the emergence of AHBZ2305 and AHBZ2310. Recombination and large variation were identified for AHBZ2312 and AHBZ2402. These findings provided insights into the transmission and evolution of PoRV among farms and underscored the need for enhanced monitoring to mitigate the risk of outbreaks from novel variants.

Passive Immunotherapy of Cynomolgus Monkeys with Anti-Rotavirus IgY.

Immunoglobulins Y (IgY) purified from egg yolks of hens represents an attractive, cost-effective alternative for the development of new diagnostic and therapeutic platforms. In this study, we evaluated the therapeutic efficacy of rotavirus-specific IgY in a cynomolgus monkey (Macaca fascicularis) model. Animals were experimentally infected with human rotavirus Group A (RVA), the most common cause of severe acute diarrhoea among young children worldwide. Animals were administered human RVA (3.1 × 107 FFU/mL) by oral gavage, challenged with 2.5 mg of anti-RVA IgY orally, and monitored for five days according to clinical, haematological and biochemical parameters; serum electrolyte levels; viral shedding; and histopathological changes. Immunotherapy with anti-RVA IgY had a protective effect against severe rotavirus-induced enteritis in four of the ten treated monkeys, as evidenced by histopathological findings. Although only one animal had diarrhoea, all but one exhibited virus shedding regardless of the treatment.

Towards the Development of a Minigenome Assay for Species A Rotaviruses.

RNA virus polymerases carry out multiple functions necessary for successful genome replication and transcription. A key tool for molecular studies of viral RNA-dependent RNA polymerases (RdRps) is a 'minigenome' or 'minireplicon' assay, in which viral RdRps are reconstituted in cells in the absence of full virus infection. Typically, plasmids expressing the viral polymerase protein(s) and other co-factors are co-transfected, along with a plasmid expressing an RNA encoding a fluorescent or luminescent reporter gene flanked by viral untranslated regions containing cis-acting elements required for viral RdRp recognition. This reconstitutes the viral transcription/replication machinery and allows the viral RdRp activity to be measured as a correlate of the reporter protein signal. Here, we report on the development of a 'first-generation' plasmid-based minigenome assay for species A rotavirus using a firefly luciferase reporter gene.

Short Communication: Rotavirus Group A Occurrence in Rural Water Source Samples in a Midwest Region State of Brazil, Comparing Wet and Dry Seasons.

Identified as a potential reference pathogen by the WHO Guidelines for Drinking-Water Quality, Rotavirus (RV) is among the main enteric viruses that cause waterborne diseases. The aim of this study was to identify and correlate the presence of RV in collective and individual water sources of rural communities in the state of Goiás, within the seasons in which the collections were made (rainy and dry seasons). For this, 86 water samples in the dry period and 160 samples in the rainy period were collected. Concentration of water samples, extraction of viral genetic material and molecular tests were performed. When analyzing the presence of RV in the samples, taking into consideration the period studied, RV was found to be more prevalent in the dry season (54.7%) than in the rainy season (20%), showing a strong statistical association with the dry season (p-value < 0.001). The presence of pathogenic microorganisms in water is a public risk issue, enabling the emergence of outbreaks, endemics and epidemics. In the present research, there was an association between the presence of Rotavirus and the dry period of the year when compared to the rainy period.

Rotavirus-Specific Maternal Serum Antibodies and Vaccine Responses to RV3-BB Rotavirus Vaccine Administered in a Neonatal or Infant Schedule in Malawi.

High titres of rotavirus-specific maternal antibodies may contribute to lower rotavirus vaccine efficacy in low- and middle-income countries (LMICs). RV3-BB vaccine (G3P[6]) is based on a neonatal rotavirus strain that replicates well in the newborn gut in the presence of breast milk. This study investigated the association between maternal serum antibodies and vaccine response in infants administered the RV3-BB vaccine. Serum was collected antenatally from mothers of 561 infants enrolled in the RV3-BB Phase II study conducted in Blantyre, Malawi, and analysed for rotavirus-specific serum IgA and IgG antibodies using enzyme-linked immunosorbent assay. Infant vaccine take was defined as cumulative IgA seroconversion (≥3 fold increase) and/or stool vaccine shedding. Maternal IgA or IgG antibody titres did not have a negative impact on vaccine-like stool shedding at any timepoint. Maternal IgG (but not IgA) titres were associated with reduced take post dose 1 (p < 0.005) and 3 (p < 0.05) in the neonatal vaccine schedule group but not at study completion (week 18). In LMICs where high maternal antibodies are associated with low rotavirus vaccine efficacy, RV3-BB in a neonatal or infant vaccine schedule has the potential to provide protection against severe rotavirus disease.

Molecular Design of Encapsulin Protein Nanoparticles to Display Rotavirus Antigens for Enhancing Immunogenicity.

Rotavirus considerably threatens global health, particularly for children <5 years. Current, licensed oral attenuated vaccine formulations have limitations including insufficient efficacy in children in low- and middle-income countries, warranting urgent development of novel vaccines with improved efficacy and safety profiles. Herein, we present a novel approach utilizing an encapsulin (ENC) nanoparticle (NP)-based non-replicating rotavirus vaccine. ENC, originating from bacteria, offers a self-assembling scaffold that displays rotavirus VP8* antigens on its surface. To enhance the correct folding and soluble expression of monomeric antigens and their subsequent assembly into NP, we adopted an RNA-interacting domain (RID) of mammalian transfer RNA synthetase as an expression tag fused to the N-terminus of the ENC-VP8* fusion protein. Using the RID-ENC-VP8* tripartite modular design, insertion of linkers of appropriate length and sequence and the universal T cell epitope P2 remarkably improved the production yield and immunogenicity. Cleavage of the RID rendered a homogenous assembly of ENC-P2-VP8* into protein NPs. Immunization with ENC-P2-VP8* induced markedly higher levels of VP8*-specific antibodies and virus neutralization titers in mice than those induced by P2-VP8* without ENC. Altogether, these results highlight the potential of the designed ENC NP-based rotavirus vaccine as an effective strategy against rotavirus disease to address global health challenges.

Effects of Rotavirus NSP4 on the Immune Response and Protection of Rotavirus-Norovirus Recombinant Subunit Vaccines in Different Immune Pathways.

Diarrheal disease continues to be a major cause of global morbidity and mortality among children under 5 years of age. To address the current issues associated with oral attenuated rotavirus vaccines, the study of parenteral rotavirus vaccines has promising prospects. In our previous study, we reported that rotavirus nonstructural protein 4 (NSP4) did not increase the IgG antibody titer of co-immune antigen but did have a protective effect against diarrhea via the intramuscular injection method. Here, we explored whether NSP4 can exert adjuvant effects on mucosal immune pathways. In this study, we immunized mice via muscle and nasal routes, gavaged them with the rotavirus Wa strain or the rotavirus SA11 strain, and then tested the protective effects of immune sera against both viruses. The results revealed that the serum-specific VP8* IgG antibody titers of the mice immunized via the nasal route were much lower than those of the mice immunized by intramuscular injection, and the specific IgA antibodies were almost undetectable in the bronchoalveolar lavage fluid (BALF). NSP4 did not increase the titer of specific VP8* antibodies in either immune pathway. Therefore, in the two vaccines (PP-NSP4-VP8* and PP-VP8*+NSP4) used in this study, NSP4 was unable to perform its potential adjuvant role through the mucosal immune pathway. Instead, NSP4 was used as a co-immunized antigen to stimulate the mice to produce specific binding antibodies that play a protective role against diarrhea.

Effectiveness of Lanzhou Lamb Rotavirus Vaccine and RotaTeq Against Hospitalized Rotavirus Infections Among Children During 2020-2023 in Guangdong Province, China: A Test-Negative Case-Control Study.

INTRODUCTION: The evidence regarding the effectiveness of Lanzhou Lamb Rotavirus Vaccine (LLR) and RotaTeq (RV5) against gastroenteritis (RVGE) caused by emerging genotypes in Chinese children remains limited. METHODS: We conducted a test-negative case-control study using gastroenteritis surveillance data from four cities (2020-2023) in Guangdong Province, China. Children aged 2 months to 5 years hospitalized with acute gastroenteritis were enrolled. Cases were rotavirus-positive; controls were rotavirus-negative. Vaccine effectiveness (VE) was estimated using multivariable logistic regressions. RESULTS: Among 2650 children, 218 (8.2%) were rotavirus-positive, predominantly G8P[8]. Also, 1543 (58.23%) children were unvaccinated, while 632 (23.85%) and 475 (17.92%) received at least one dose of RV5 and LLR, respectively. Adjusted RV5 VE against any RVGE severity was 51.7% [95% confidence interval (CI) - 58.1-85.3%]) for one dose, 37.6% (95% CI - 58.5-75.4%) for two doses, and 64.1% (95% CI 38.0-79.2%) for three doses. For LLR, VE against any RVGE severity was 38.7% (95% CI 5.7-60.2%) for one dose, 74.6% (95% CI 35.3-90.0%) for two doses, and 58.8% (95% CI - 217.6-94.6%) for three doses. Against severe RVGE, RV5 VE was 67.2% (95% CI - 144.7-95.6%) for one dose, 74.0% (95% CI - 92.1-96.5%) for two doses, and 86.6% (95% CI 56.8-95.9%) for three doses. For LLR, VE against severe RVGE was 57.7% (95% CI 20.3-77.6%) for one dose, 73.4% (95% CI 11.9-92.0%) for two doses, and - 27.8% (95% CI - 949.7-84.4%) for three doses. CONCLUSIONS: Both RV5 and LLR provided protection against RVGE, including the emerging G8P[8] genotype. Three doses of RV5 offered strong protection, while two doses of LLR also appeared to be an effective strategy against rotavirus infection.

Rotavirus is a common cause of severe diarrhea in young children, and vaccines are crucial in preventing this illness. This study looked at how well two rotavirus vaccines, Lanzhou Lamb Rotavirus Vaccine (LLR) and RotaTeq (RV5), protect children against rotavirus gastroenteritis (RVGE), including infections caused by a new strain called G8P[8]. We analyzed data from children aged 2 months to 5 years who were hospitalized between 2020 and 2023. We compared children who tested positive for rotavirus (cases) with those who tested negative (controls) to determine how well the vaccines worked. Our results showed that both RV5 and LLR vaccines provided protection against RVGE. For RV5, three doses provided strong protection, while for LLR, two doses provided good protection. Against severe RVGE, three doses of RV5 were effective, while two doses of LLR also showed good protection.