Human Rotavirus Research Articles

The Probiotic Strain Lactobacillus fermentum 39: Biochemical Properties, Genomic Features, and Antiviral Activity

Lactobacillus fermentum 39 is a well-known probiotic strain, which is widely used for production of pharmacopoeial probiotic preparations, dietary supplements, and foodstuffs enriched with probiotic microorganisms. In the course of analysis by transmission electron microscopy, the cell morphology was studied, biochemical properties of the strain and strain-specific characteristics of sugar metabolism were thoroughly analyzed, its full genome was sequenced, and the cluster of genes responsible for exopolysaccharide synthesis was characterized. The cells of Lactobacillus fermentum 39 were shown to be capable of adsorbing rotavirus particles, which allows us to substantiate a new aspect of application of probiotics, including this strain, in acute gastroenteritis caused by human rotaviruses.

High prevalence of circulating DS-1-like human rotavirus A and genotype diversity in children with acute gastroenteritis in Thailand from 2016 to 2019.

BackgroundHuman rotavirus A (RVA) infection is the primary cause of acute gastroenteritis (AGE) in infants and young children worldwide, especially in children under 5 years of age and is a major public health problem causing severe diarrhea in children in Thailand. This study aimed to investigate the prevalence, genotype diversity, and molecular characterization of rotavirus infection circulating in children under 15 years of age diagnosed with AGE in Thailand from January 2016 to December 2019.MethodsA total of 2,001 stool samples were collected from children with gastroenteritis (neonates to children <15 years of age) and tested for RVA by real-time polymerase chain reaction (RT-PCR). Amplified products were sequenced and submitted to an online genotyping tool for analysis.ResultsOverall, 301 (15.0%) stool samples were positive for RVA. RVA occurred most frequently among children aged 0-24 months. The seasonal incidence of rotavirus infection occurred typically in Thailand during the winter months (December-March). The G3P[8] genotype was identified as the most prevalent genotype (33.2%, 100/301), followed by G8P[8] (10.6%, 32/301), G9P[8] (6.3%, 19/301), G2P[4] (6.0%, 18/301), and G1P[6] (5.3%, 16/301). Uncommon G and P combinations such as G9P[4], G2P[8], G3P[4] and G3P[9] were also detected at low frequencies. In terms of genetic backbone, the unusual DS-1-like G3P[8] was the most frequently detected (28.2%, 85/301), and the phylogenetic analysis demonstrated high nucleotide identity with unusual DS-1-like G3P[8] detected in Thailand and several countries.ConclusionsA genetic association between RVA isolates from Thailand and other countries ought to be investigated given the local and global dissemination of rotavirus as it is crucial for controlling viral gastroenteritis, and implications for the national vaccination programs.

Enteric viruses in lentic and lotic freshwater habitats from Brazil's Midwest and South regions in the Guarani Aquifer area.

The present study reports the monitoring of viruses indicating fecal contamination in two distinct regions affected by poor management of wastewater located above the Guarani Aquifer, which is one of the biggest freshwater reservoirs in the world. In the city of Três Lagoas (located in the Midwest region, in the state of Mato Grosso do Sul), water samples were collected from Lagoa Maior, a lake used for recreation, and in Concórdia (located in the South region, in the state of Santa Catarina), from the Queimados River, which crosses the urban area. Four sampling sites were monitored from March to July 2018 in Lagoa Maior, and four sampling sites were monitored along the urban part of the Queimados River area over two periods (rainy and dry). Water samples were analyzed by concentration of Human adenovirus (HAdV), Norovirus (NoV), Rotavirus A (RAV), and Hepatitis A virus (HAV) for the Lagoa Maior samples and RVA, HAV, and Porcine circovirus 2 (PCV2) for the Queimados River samples. All sampling sites presented enteric viruses, demonstrating fecal input and potential contamination of groundwater. Results highlight the need for wastewater management to improve environmental health quality.

Escherichia coli Nissle 1917 administered as a dextranomar microsphere biofilm enhances immune responses against human rotavirus in a neonatal malnourished pig model colonized with human infant fecal microbiota

Human rotavirus (HRV) is a leading cause of diarrhea in children. It causes significant morbidity and mortality, especially in low- and middle-income countries (LMICs), where HRV vaccine efficacy is low. The probiotic Escherichia coli Nissle (EcN) 1917 has been widely used in the treatment of enteric diseases in humans. However, repeated doses of EcN are required to achieve maximum beneficial effects. Administration of EcN on a microsphere biofilm could increase probiotic stability and persistence, thus maximizing health benefits without repeated administrations. Our aim was to investigate immune enhancement by the probiotic EcN adhered to a dextranomar microsphere biofilm (EcN biofilm) in a neonatal, malnourished piglet model transplanted with human infant fecal microbiota (HIFM) and infected with rotavirus. To create malnourishment, pigs were fed a reduced amount of bovine milk. Decreased HRV fecal shedding and protection from diarrhea were evident in the EcN biofilm treated piglets compared with EcN suspension and control groups. Moreover, EcN biofilm treatment enhanced natural killer cell activity in blood mononuclear cells (MNCs). Increased frequencies of activated plasmacytoid dendritic cells (pDC) in systemic and intestinal tissues and activated conventional dendritic cells (cDC) in blood and duodenum were also observed in EcN biofilm as compared with EcN suspension treated pigs. Furthermore, EcN biofilm treated pigs had increased frequencies of systemic activated and resting/memory antibody forming B cells and IgA+ B cells in the systemic tissues. Similarly, the mean numbers of systemic and intestinal HRV-specific IgA antibody secreting cells (ASCs), as well as HRV-specific IgA antibody titers in serum and small intestinal contents, were increased in the EcN biofilm treated group. In summary EcN biofilm enhanced innate and B cell immune responses after HRV infection and ameliorated diarrhea following HRV challenge in a malnourished, HIFM pig model.

Human Colostrum and Derived Extracellular Vesicles Prevent Infection by Human Rotavirus and Respiratory Syncytial Virus in Vitro.

It is known that breastfeeding protects the infant from enteric and respiratory infections; however, the antiviral properties of human milk against enteric and respiratory viruses are largely unexplored. To explore the antiviral activity of human preterm colostrum against rotavirus and respiratory syncytial virus and to assess whether the derived extracellular vesicle contribute to this activity. We used a cross-sectional, prospective two-group non-experimental design. Colostra were collected from mothers of preterm newborns (N = 10) and extracellular vesicles were purified and characterized. The antiviral activity of colostra and derived extracellular vesicles were tested in vitro against rotavirus and respiratory syncytial virus and the step of viral replication inhibited by extracellular vesicles was investigated. Each sample of colostrum and colostrum-derived extracellular vesicles had significant antiviral activity with a wide interpersonal variability. Mechanism of action studies demonstrated that extracellular vesicles acted by interfering with the early steps of the viral replicative cycle. We demonstrated the intrinsic antiviral activity of human colostrum against rotavirus and respiratory syncytial virus and we showed that extracellular vesicles substantially contribute to the overall protective effect. Our results contribute to unravelling novel mechanisms underlying the functional role of human milk as a protective and therapeutic agent in preterm infants.

Infection of porcine small intestinal enteroids with human and pig rotavirus A strains reveals contrasting roles for histo-blood group antigens and terminal sialic acids.

Rotaviruses (RVs) are a leading cause of acute viral gastroenteritis in young children and livestock worldwide. Growing evidence suggests that host cellular glycans, such as histo-blood group antigens (HBGAs) and sialic acids (SA), are recognized by the RV surface protein VP4. However, a mechanistic understanding of these interactions and their effects on RV infection and pathogenesis is lacking. Here, we established a porcine crypt-derived 3D intestinal enteroids (PIEs) culture system which contains all intestinal epithelial cells identified in vivo and represents a unique physiologically functional model to study RV-glycan interactions in vitro. PIEs expressing different HBGAs (A+, H+, and A+/H+) were established and isolation, propagation, differentiation and RV infection conditions were optimized. Differentiated PIEs were infected with human RV (HRV) G1P[8] Wa, porcine RV (PRV) G9P[13], PRV Gottfried G4P[6] or PRV OSU G5P[7] virulent and attenuated strains and virus replication was measured by qRT-PCR. Our results indicated that virulent HRV G1P[8] Wa replicated to the highest titers in A+ PIEs, while a distinct trend was observed for PRV G9P[13] or G5P[7] with highest titers in H+ PIEs. Attenuated Wa and Gottfried strains replicated poorly in PIEs while the replication of attenuated G9P[13] and OSU strains in PIEs was relatively efficient. However, the replication of all 4 attenuate strains was less affected by the PIE HBGA phenotypes. HBGA synthesis inhibitor 2-F-Peracetyl-Fucose (2F) treatment demonstrated that HBGAs are essential for G1P[8] Wa replication; however, they may only serve as a cofactor for PRVs G9P[13] and OSU G5P[7]. Interestingly, contrasting outcomes were observed following sialidase treatment which significantly enhanced G9P[13] replication, but inhibited the growth of G5P[7]. These observations suggest that some additional receptors recognized by G9P[13] become unmasked after removal of terminal SA. Overall, our results confirm that differential HBGAs-RV and SA-RV interactions determine replication efficacy of virulent group A RVs in PIEs. Consequently, targeting individual glycans for development of therapeutics may not yield uniform results for various RV strains.

Genetic characterization of G12P[6] and G12P[8] rotavirus strains collected in six African countries between 2010 and 2014

BackgroundG12 rotaviruses were first observed in sub-Saharan Africa in 2004 and since then have continued to emerge and spread across the continent and are reported as a significant human rotavirus genotype in several African countries, both prior to and after rotavirus vaccine introduction. This study investigated the genetic variability of 15 G12 rotavirus strains associated with either P[6] or P[8] identified between 2010 and 2014 from Ethiopia, Kenya, Rwanda, Tanzania, Togo and Zambia.MethodsThe investigation was carried out by comparing partial VP7 and partial VP4 sequences of the African G12P[6] and G12P[8] strains with the available GenBank sequences and exploring the recognized neutralization epitopes of these strains. Additionally, Bayesian evolutionary analysis was carried out using Markov Chain Monte Carlo (MCMC) implemented in BEAST to estimate the time to the most recent ancestor and evolutionary rate for these G12 rotavirus strains.ResultsThe findings suggested that the VP7 and VP4 nucleotide and amino acid sequences of the G12 strains circulating in African countries are closely related, irrespective of country of origin and year of detection, with the exception of the Ethiopian strains that clustered distinctly. Neutralization epitope analysis revealed that rotavirus VP4 P[8] genes associated with G12 had amino acid sequences similar to those reported globally including the vaccine strains in RotaTeq and Rotarix. The estimated evolutionary rate of the G12 strains was 1.016 × 10− 3 substitutions/site/year and was comparable to what has been previously reported. Three sub-clusters formed within the current circulating lineage III shows the diversification of G12 from three independent ancestries within a similar time frame in the late 1990s.ConclusionsAt present it appears to be unlikely that widespread vaccine use has driven the molecular evolution and sustainability of G12 strains in Africa. Continuous monitoring of rotavirus genotypes is recommended to assess the long-term impact of rotavirus vaccination on the dynamic nature of rotavirus evolution on the continent.

Inactivation of Foodborne Viruses by High-Pressure Processing (HPP).

High-pressure processing (HPP) is an innovative non-thermal food preservation method. HPP can inactivate microorganisms, including viruses, with minimal influence on the physicochemical and sensory properties of foods. The most significant foodborne viruses are human norovirus (HuNoV), hepatitis A virus (HAV), human rotavirus (HRV), hepatitis E virus (HEV), human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV), and enterovirus (EV), which have also been implicated in foodborne outbreaks in various countries. The HPP inactivation of foodborne viruses in foods depends on high-pressure processing parameters (pressure, temperature, and duration time) or non-processing parameters such as virus type, food matrix, water activity (aw), and the pH of foods. HPP was found to be effective for the inactivation of foodborne viruses such as HuNoV, HAV, HAstV, and HuAdV in foods. HPP treatments have been found to be effective at eliminating foodborne viruses in high-risk foods such as shellfish and vegetables. The present work reviews the published data on the effect of HPP processing on foodborne viruses in laboratory media and foods.

Interaction of Intestinal Bacteria with Human Rotavirus during Infection in Children.

The gut microbiota has emerged as a key factor in the pathogenesis of intestinal viruses, including enteroviruses, noroviruses and rotaviruses (RVs), where stimulatory and inhibitory effects on infectivity have been reported. With the aim of determining whether members of the microbiota interact with RVs during infection, a combination of anti-RV antibody labeling, fluorescence-activated cell sorting and 16S rRNA amplicon sequencing was used to characterize the interaction between specific bacteria and RV in stool samples of children suffering from diarrhea produced by G1P[8] RV. The genera Ruminococcus and Oxalobacter were identified as RV binders in stools, displaying enrichments between 4.8- and 5.4-fold compared to samples nonlabeled with anti-RV antibodies. In vitro binding of the G1P[8] Wa human RV strain to two Ruminococcus gauvreauii human isolates was confirmed by fluorescence microscopy. Analysis in R. gauvreauii with antibodies directed to several histo-blood group antigens (HBGAs) indicated that these bacteria express HBGA-like substances on their surfaces, which can be the target for RV binding. Furthermore, in vitro infection of the Wa strain in differentiated Caco-2 cells was significantly reduced by incubation with R. gauvreauii. These data, together with previous findings showing a negative correlation between Ruminococcus levels and antibody titers to RV in healthy individuals, suggest a pivotal interaction between this bacterial group and human RV. These results reveal likely mechanisms of how specific bacterial taxa of the intestinal microbiota could negatively affect RV infection and open new possibilities for antiviral strategies.

At Least Seven Distinct Rotavirus Genotype Constellations in Bats with Evidence of Reassortment and Zoonotic Transmissions.

Bats host many viruses pathogenic to humans, and increasing evidence suggests that rotavirus A (RVA) also belongs to this list. Rotaviruses cause diarrheal disease in many mammals and birds, and their segmented genomes allow them to reassort and increase their genetic diversity. Eighteen out of 2,142 bat fecal samples (0.8%) collected from Europe, Central America, and Africa were PCR-positive for RVA, and 11 of those were fully characterized using viral metagenomics. Upon contrasting their genomes with publicly available data, at least 7 distinct bat RVA genotype constellations (GCs) were identified, which included evidence of reassortments and 6 novel genotypes. Some of these constellations are spread across the world, whereas others appear to be geographically restricted. Our analyses also suggest that several unusual human and equine RVA strains might be of bat RVA origin, based on their phylogenetic clustering, despite various levels of nucleotide sequence identities between them. Although SA11 is one of the most widely used reference strains for RVA research and forms the backbone of a reverse genetics system, its origin remained enigmatic. Remarkably, the majority of the genotypes of SA11-like strains were shared with Gabonese bat RVAs, suggesting a potential common origin. Overall, our findings suggest an underexplored genetic diversity of RVAs in bats, which is likely only the tip of the iceberg. Increasing contact between humans and bat wildlife will further increase the zoonosis risk, which warrants closer attention to these viruses.IMPORTANCE The increased research on bat coronaviruses after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) allowed the very rapid identification of SARS-CoV-2. This is an excellent example of the importance of knowing viruses harbored by wildlife in general, and bats in particular, for global preparedness against emerging viral pathogens. The current effort to characterize bat rotavirus strains from 3 continents sheds light on the vast genetic diversity of rotaviruses and also hints at a bat origin for several atypical rotaviruses in humans and animals, implying that zoonoses of bat rotaviruses might occur more frequently than currently realized.

Identification of Coronaviruses, Paramyxoviruses, Reoviruses, and Rotaviruses among Bats in Nigeria.

Bats are often consumed by some ethnic groups in Nigeria despite association of bats with many important emerging viruses. More than 300 bats representing eight species were captured during 2010-2011 in eight locations of northern Nigeria. Available fecal swabs (n = 95) were screened for the presence of arenaviruses, CoVs, paramyxoviruses (PMVs), reoviruses, rhabdoviruses, and influenza viruses using generic reverse transcription-polymerase chain reaction assays. Here, we document the detection of CoVs, PMVs, reoviruses, and rotaviruses (RVs) in Nigerian bats. The Nigerian bat CoVs are grouped within other bat SARS-CoV-like viruses identified from Ghana in a sister clade next to the human SARS-CoV clade. The phylogenetic analysis indicated a broad range of RVs present in Nigerian bats, some cluster with human RVs and some represent novel species. Our study adds that continuing global surveillance for viruses in bats to understand their origin, adaptation, and evolution is important to prevent and control future zoonotic disease outbreaks.

Immunogenicity, safety and reactogenicity of ROTAVAC® in healthy infants aged 6–8 weeks in Vietnam

BackgroundROTAVAC® is derived from human 116E rotavirus (RV) neonatal strain. In this study, we evaluated the immunogenicity, safety and reactogenicity of ROTAVAC® in Vietnam. MethodWe conducted a phase IV clinical trial in healthy infants aged 6–8 weeks using the complete regimen of ROTAVAC® with three doses. Serum anti-RV IgA was measured by enzyme-linked immunosorbent assay to assess the geometric mean concentration in infants who received the complete regimen of the vaccine. ResultsA total of 360 participants were enrolled in this clinical trial. The mean age ± standard deviation at enrollment was 6.9 ± 0.6 weeks. The anti-RV IgA titer was 4.01 ± 3.74 mg/ml pre-vaccination and substantially increased to 29.27 ± 80.64 mg/ml post-vaccination. The value of logIgA significantly increased (p = 0.003) from 0.28 ± 0.79 to 1.03 ± 0.54. The proportion of participants with equal to and greater than 3-fold and 4-fold shifts in pre- to post-vaccination antibody titer (IgA) were 55.4% and 48.3%, respectively. No adverse events or serious adverse events were recorded immediately within 30 min after the administration of each dose. The most common adverse events within 14 days after each visit were fever, unusual crying and irritability. Other adverse events occurred at a low rate, and no case of intussusception was noted. ConclusionsThe complete regimen of ROTAVAC® demonstrated an immunological response with clinically acceptable safety profile. Post-completion of this study, ROTAVAC® is now a WHO-prequalified vaccine and available in Vietnam.

Enteric Viruses and Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), is a multifactorial disease in which dietary, genetic, immunological, and microbial factors are at play. The role of enteric viruses in IBD remains only partially explored. To date, epidemiological studies have not fully described the role of enteric viruses in inflammatory flare-ups, especially that of human noroviruses and rotaviruses, which are the main causative agents of viral gastroenteritis. Genome-wide association studies have demonstrated the association between IBD, polymorphisms of the FUT2 and FUT3 genes (which drive the synthesis of histo-blood group antigens), and ligands for norovirus and rotavirus in the intestine. The role of autophagy in defensin-deficient Paneth cells and the perturbations of cytokine secretion in T-helper 1 and T-helper 17 inflammatory pathways following enteric virus infections have been demonstrated as well. Enteric virus interactions with commensal bacteria could play a significant role in the modulation of enteric virus infections in IBD. Based on the currently incomplete knowledge of the complex phenomena underlying IBD pathogenesis, future studies using multi-sampling and data integration combined with new techniques such as human intestinal enteroids could help to decipher the role of enteric viruses in IBD.

Whole Genome Analysis of African G12P[6] and G12P[8] Rotaviruses Provides Evidence of Porcine-Human Reassortment at NSP2, NSP3, and NSP4.

Group A rotaviruses (RVA) represent the most common cause of pediatric gastroenteritis in children <5 years, worldwide. There has been an increase in global detection and reported cases of acute gastroenteritis caused by RVA genotype G12 strains, particularly in Africa. This study sought to characterize the genomic relationship between African G12 strains and determine the possible origin of these strains. Whole genome sequencing of 34 RVA G12P[6] and G12P[8] strains detected from the continent including southern (South Africa, Zambia, Zimbabwe), eastern (Ethiopia, Uganda), central (Cameroon), and western (Togo) African regions, were sequenced using the Ion Torrent PGM method. The majority of the strains possessed a Wa-like backbone with consensus genotype constellation of G12-P[6]/P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1, while a single strain from Ethiopia displayed a DS-1-like genetic constellation of G12-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2. In addition, three Ethiopian and one South African strains exhibited a genotype 2 reassortment of the NSP3 gene, with genetic constellation of G12-P[8]-I1-R1-C1-M1-A1-N1-T2-E1-H1. Overall, 10 gene segments (VP1–VP4, VP6, and NSP1–NSP5) of African G12 strains were determined to be genetically related to cognate gene sequences from globally circulating human Wa-like G12, G9, and G1 strains with nucleotide (amino acid) identities in the range of 94.1–99.9% (96.5–100%), 88.5–98.5% (93–99.1%), and 89.8–99.0% (88.7–100%), respectively. Phylogenetic analysis showed that the Ethiopian G12P[6] possessing a DS-1-like backbone consistently clustered with G2P[4] strains from Senegal and G3P[6] from Ethiopia with the VP1, VP2, VP6, and NSP1–NSP4 genes. Notably, the NSP2, NSP3, and NSP4 of most of the study strains exhibited the closest relationship with porcine strains suggesting the occurrence of reassortment between human and porcine strains. Our results add to the understanding of potential roles that interspecies transmission play in generating human rotavirus diversity through reassortment events and provide insights into the evolutionary dynamics of G12 strains spreading across selected sub-Saharan Africa regions.

The Complex Interactions Between Rotavirus and the Gut Microbiota.

Human rotavirus (HRV) is the leading worldwide cause of acute diarrhea-related death in children under the age of five. RV infects the small intestine, an important site of colonization by the microbiota, and studies over the past decade have begun to reveal a complex set of interactions between RV and the gut microbiota. RV infection can temporarily alter the composition of the gut microbiota and probiotic administration alleviates some symptoms of infection in vivo, suggesting reciprocal effects between the virus and the gut microbiota. While development of effective RV vaccines has offered significant protection against RV-associated mortality, vaccine effectiveness in low-income countries has been limited, potentially due to regional differences in the gut microbiota. In this mini review, we briefly detail research findings to date related to HRV vaccine cohorts, studies of natural infection, explorations of RV-microbiota interactions in gnotobiotic pig models, and highlight various in vivo and in vitro models that could be used in future studies to better define how the microbiota may regulate RV infection and host antiviral immune responses.

Research progress of qiweibaizhu powder in treating digestive system diseases

Diarrhea is a common clinical problem that can lead to health complications, including death. It is the second-most common cause of death in children. The World Health Organization introduced a program to encourage the development and use of traditional herbal medicines in the treatment of diarrhea. Qiweibaizhu Powder (QWBZP) is a well-known pediatric prescription in China that is commonly used to treat digestive system diseases, such as diarrhea, which is also a type of syndrome in traditional Chinese medicine. Many studies have examined the clinical effects and mechanisms of QWBZP, and innovative and improved formulations have been developed. Recent studies on the effects of QWBZP on diarrhea caused by human rotavirus, antibiotic-associated diarrhea, and mesenteric lymphadenitis in experimental models and clinical trials with diarrhea patients have been reviewed. We conducted a literature search of several databases, including PubMed, China National Knowledge Infrastructure, Chongqing VIP Information Co., Ltd., and Wanfang. A short background of the QWBZP is also provided. The collective findings highlight the curative effects of QWBZP on diarrhea caused by viral infection, antibiotic use, and mesenteric lymphadenitis. Furthermore, QWBZP can regulate the balance of the gastrointestinal microbiota and protect and repair the intestinal mucosal barrier. This review will provide a reference for further studies on QWBZP.

Vaccination services and incomplete vaccine coverage for children: a comparative spatial analysis of the BRISA cohorts, São Luís (Maranhão State) and Ribeirão Preto (São Paulo State), Brazil.

We analyzed the spatial relation between incomplete vaccine coverage for children and the distance from vaccination services. This was a cross-sectional study of children from 13 to 35 months of age from the cities of São Luís (Maranhão State) and Ribeirão Preto (São Paulo State), Brazil, and from basic health units (UBS, in Portuguese). The sample consisted of 2,744 children from São Luís and 3,325 from Ribeirão Preto. Data about incomplete vaccine coverage for children were obtained from the BRISA birth cohorts. Data about the quality of UBS vaccination services were obtained from the first cycle of the Brazilian National Program for Improvement of Access and Quality of Basic Care (PMAQ-AB, in Portuguese). For the spatial analysis, we determined the distance between the residence of the children (with and without a complete vaccine calendar) and the vaccination services of the UBS (classified according to number of structural items). Incomplete vaccine coverage was more pronounced in São Luís, with greater percentages for human rotavirus and triple viral vaccines, with the latter being the least available. In Ribeirão Preto, incomplete BCG vaccine coverage was more pronounced, with the tetravalent vaccine being the least available. Children from the two cities showed similarities: most of them had adult mothers with 9 to 11 years of schooling and did not reside with siblings in the household. They also showed differences: in São Luís, most mothers belonged to the economic class C, while in Ribeirão Preto they belong to the A and B classes. In the two cities with different socioeconomic conditions, complete vaccine coverage seemed not to depend on the location or quality of the vaccination service. Although São Luís showed a better structure of the services, incomplete vaccine coverage was higher compared to Ribeirão Preto.

INFLUENCE OF HUMAN ROTAVIRUS VACCINE IN HOSPITALIZATIONS FOR GASTROENTERITIS IN CHILDREN IN BRAZIL

ABSTRACT Objectives: to describe and analyze the influence of human rotavirus vaccine on hospitalizations for gastroenteritis in children under 5 years of age, in Brazil, 2001 to 2018 (pre- and post-vaccination period). Method: this is a retrospective, descriptive ecological study, combining the description of a time series from 2001 to 2018 and collected in the months August 2019 to Janaury 2020. The data were obtained from a secondary source. To analyze the effect of different variables, multiple models of mathematical evaluations were used (accumulated growth rate, geometric growth rate; standard deviation, mean, variance and simple linear regression). The level of significance was set at 5% (p &lt;0.05). Results: there was a reduction in hospitalizations related to gastroenteritis in children under 5 years old, when comparing the pre- and post-vaccination periods. This reduction occurred in all Brazilian regions. Conclusion: after the implementation of human rotavirus vaccine, there was a significant reduction in hospitalizations of children under 5 years.

1385. Concomitant Administration of Liquid Porcine Circovirus-free Human Rotavirus Vaccine with Routine Pediatric Vaccines Does Not Impact Immune Responses in Infants: Results from a Phase 3, Randomized Trial in the United States

BackgroundPorcine circovirus type 1 (PCV-1) material was detected in the human rotavirus vaccine (HRV) in 2010. Although no safety risk was identified for infants vaccinated with HRV, a PCV-free HRV (no detection of PCV-1 and PCV-2 according to the limit of the tests used) was developed, which showed comparable immunogenicity and safety profile to the initial HRV. We assessed the non-inferiority of immune responses elicited by routine vaccines (co-)administered with either liquid (Liq) PCV-free HRV or lyophilized (Lyo) HRV, and the immunogenicity and safety of HRVs in infants.MethodsIn this phase 3, randomized, single-blind study (NCT03207750) in the United States, healthy infants aged 6–12 weeks received 2 doses of Liq PCV-free HRV or Lyo HRV at study month (M)0, M2 and routine vaccines at M0, M2, M4 (Figure 1). Co-primary objectives were to hierarchically demonstrate non-inferiority of immune responses to routine vaccine antigens when (co-)administered with Liq PCV-free HRV compared to Lyo HRV, 1 month post-dose 3 of the routine vaccines and to rule out a 10% decrease in seroresponse to pertussis antigens. Immunogenicity and safety of HRVs were also evaluated (Figure 1).Figure 1. Study design Results1272 infants were vaccinated and 990 (Liq PCV-free HRV: 489; Lyo HRV: 501) were included in the per-protocol set. All statistical criteria were met for the 2 co-primary objectives (Table 1). Seroprotection/seropositivity rates were ≥ 99.3% for all DTaP-HBV-IPV antigens, ≥ 97.4% for Hib and ≥ 90.8% for most PCV13 serotypes. Geometric mean concentrations/titers for the routine vaccine antigens were comparable between groups (Table 2). 76.3% of infants in Liq PCV-free HRV and 78.9% in Lyo HRV had anti-RV antibody concentration ≥ 20 U/mL. The incidence of solicited (Figure 2) and unsolicited adverse events (AEs) were similar in both groups. Of 75 serious AEs (SAEs), 2 (Lyo HRV: abdominal distension; intussusception) were considered vaccine-related by investigator; 1 fatal SAE (Liq PCV-free HRV: sudden infant death syndrome) was considered non-vaccine related by investigator.Table 1. Non-inferiority of the immune responses to routine vaccine antigens when (co-)administered with HRV (Liq PCV-free HRV vs Lyo HRV) and exclusion of 10% decrease in seroresponse to pertussis antigens, 1 month post-dose 3 (per-protocol set) Table 2. Seroprotection/seropositivity rates and geometric mean concentrations/titers for the routine vaccines antigens 1 month post-dose 3 (per-protocol set) Figure 2. The incidence of solicited adverse events occurring within 7 days post-vaccination (overall/infant, exposed set) ConclusionRoutine vaccines (co-)administered with Liq PCV-free HRV showed non-inferior immune responses and similar safety profiles compared to (co-)administration with Lyo HRV.FundingGlaxoSmithKline Biologicals SADisclosuresRemon Abu-Elyazeed, MD, PhD, GSK group of companies (Employee) Nicola P. Klein, MD, PhD, GSK group of companies (Research Grant or Support)Merck (Grant/Research Support)Pfizer (Grant/Research Support)Protein Science (now SP) (Grant/Research Support)Sanofi Pasteur (Grant/Research Support) Leentje Moerman, PhD, GSK group of companies (Employee) Michael Povey, MSc, GSK group of companies (Employee) Shelly Senders, MD, Pfizer (Grant/Research Support) Dan Bi, MD, MPH, GSK group of companies (Employee)

Reverse Genetics Approach for Developing Rotavirus Vaccine Candidates Carrying VP4 and VP7 Genes Cloned from Clinical Isolates of Human Rotavirus.

Species A rotaviruses (RVs) are a leading cause of severe acute gastroenteritis in infants and children younger than 5 years. Currently available RV vaccines were adapted from wild-type RV strains by serial passage of cultured cells or by reassortment between human and animal RV strains. These traditional methods require large-scale screening and genotyping to obtain vaccine candidates. Reverse genetics is a tractable, rapid, and reproducible approach to generating recombinant RV vaccine candidates carrying any VP4 and VP7 genes that provide selected antigenicity. Here, we developed a vaccine platform by generating recombinant RVs carrying VP4 (P[4] and P[8]), VP7 (G1, G2, G3, G8, and G9), and/or VP6 genes cloned from human RV clinical samples using the simian RV SA11 strain (G3P[2]) as a backbone. Neutralization assays using monoclonal antibodies and murine antisera revealed that recombinant VP4 and VP7 monoreassortant viruses exhibited altered antigenicity. However, replication of VP4 monoreassortant viruses was severely impaired. Generation of recombinant RVs harboring a chimeric VP4 protein for SA11 and human RV gene components revealed that the VP8* fragment was responsible for efficient infectivity of recombinant RVs. Although this system must be improved because the yield of vaccine viruses directly affects vaccine manufacturing costs, reverse genetics requires less time than traditional methods and enables rapid production of safe and effective vaccine candidates.IMPORTANCE Although vaccines have reduced global RV-associated hospitalization and mortality over the past decade, the multisegmented genome of RVs allows reassortment of VP4 and VP7 genes from different RV species and strains. The evolutionary dynamics of novel RV genotypes and their constellations have led to great genomic and antigenic diversity. The reverse genetics system is a powerful tool for manipulating RV genes, thereby controlling viral antigenicity, growth capacity, and pathogenicity. Here, we generated recombinant simian RVs (strain SA11) carrying heterologous VP4 and VP7 genes cloned from clinical isolates and showed that VP4- or VP7-substituted chimeric viruses can be used for antigenic characterization of RV outer capsid proteins and as improved seed viruses for vaccine production.