Severe Rotavirus Gastroenteritis Research Articles

Effectiveness and Safety of Bovine Human Pentavalent Rotavirus Vaccine (BRV-PV) in Preventing Severe Acute Rotavirus Gastroenteritis (SRVGE): A systematic review of the experience in developing countries

Background: Severe acute rotavirus gastroenteritis (SRVGE) is the world's highest cause of children mortality, with symptoms of severe dehydrating diarrhea due to rotavirus (RV) infection. SRVGE provides a high economic burden, mostly in developing countries. Currently, three RV vaccines (Rotarix, RotaTeq, Rotavac) are licensed internationally by the World Health Organization (WHO) and are not yet applicable in developing countries. Hence, research shows the potential of BRV-PV in preventing RV infection in pediatrics, especially in developing countries. Objective: This review aims to analyze the effectiveness and safety of BRV-PV in developing countries. Methods: This systematic review includes studies from the ScienceDirect, PubMed, Elsevier, and Cochrane databases that met the inclusion and exclusion criteria. The search method uses the Boolean operator with the articles from the last ten years. Eight articles with a total of 9088 children were reviewed to analyze the effectiveness and safety of BRV-PV. Results and Discussion: Of all the studies involved, BRV-PV has effectively reduced the incidence of hospitalization and emergency cases due to SRVGE. Furthermore, BRV-PV is also safe for children in developing countries, proven by increased anti-RV IgA concentrations and minimal side effects. Conclusion: BRV-PV is more effective, safe, heat-stable, and affordable than the previous three RV vaccines in developing countries Keyword: BRV-PV, Gastroenteritis, Rotavirus, Rotavirus Vaccine Latar Belakang: Severe acute rotavirus gastroenteritis (SRVGE) merupakan penyebab kematian anak tertinggi di dunia dengan gejala diare dehidrasi parah akibat infeksi rotavirus (RV). SRVGE memberikan beban ekonomi yang tinggi, terutama di negara-negara berkembang. Saat ini, tiga vaksin RV (Rotarix, RotaTeq, Rotavac) dilisensikan secara internasional oleh World Health Organization (WHO) dan belum dapat diterapkan di negara-negara berkembang. Oleh karena itu, penelitian menunjukkan potensi BRV-PV dalam mencegah infeksi RV pada anak-anak, khususnya di negara berkembang. Tujuan: Ulasan ini bertujuan untuk menganalisis efektivitas dan keamanan BRV-PV dalam mencegah SRVGE. Metode: Tinjauan sistematis ini mencakup studi dari database ScienceDirect, PubMed, Elsevier, dan Cochrane yang memenuhi kriteria inklusi dan eksklusi. Metode pencariannya menggunakan operator boolean dengan artikel sepuluh tahun terakhir. Delapan artikel dengan total 9088 pediatri ditinjau untuk menganalisis efektivitas dan keamanan BRV-PV. Hasil dan Pembahasan: Dari semua penelitian yang terlibat, BRV-PV telah secara efektif mengurangi kejadian rawat inap dan kasus darurat akibat SRVGE. Selain itu, BRV-PV juga aman untuk anak-anak di negara berkembang, terbukti dengan peningkatan konsentrasi IgA anti-RV dan efek samping yang minimal. Kesimpulan: BRV-PV lebih efektif, aman, tahan panas, dan terjangkau dibandingkan tiga vaksin RV sebelumnya di negara berkembang.. Kata Kunci: BRV-PV, Gastroenteritis, Rotavirus, Vaksin Rotavirus

Safety of Rotavirus Vaccination in Preterm Infants Admitted in Neonatal Intensive Care Units in Sicily, Italy: A Multicenter Observational Study.

Rotavirus (RV) is among the most common vaccine-preventable diseases in children under five years of age. Despite the severity of rotavirus pathology in early childhood, rotavirus vaccination for children admitted to the neonatal intensive care unit (NICU), who are often born preterm and with various previous illnesses, is not performed. This multicenter, 3-year project aims to evaluate the safety of RV vaccine administration within the six main neonatal intensive care units of the Sicilian Region to preterm infants. Methods: Monovalent live attenuated anti-RV vaccination (RV1) was administered from April 2018 to December 2019 to preterm infants with gestational age ≥ 28 weeks. Vaccine administrations were performed in both inpatient and outpatient hospital settings as a post-discharge follow-up (NICU setting) starting at 6 weeks of age according to the official immunization schedule. Any adverse events (expected, unexpected, and serious) were monitored from vaccine administration up to 14 days (first assessment) and 28 days (second assessment) after each of the two scheduled vaccine doses. Results: At the end of December 2019, 449 preterm infants were vaccinated with both doses of rotavirus vaccine within the six participating Sicilian NICUs. Mean gestational age in weeks was 33.1 (±3.8 SD) and the first dose of RV vaccine was administered at 55 days (±12.9 SD) on average. The mean weight at the first dose was 3388 (SD ± 903) grams. Only 0.6% and 0.2% of infants reported abdominal colic and fever above 38.5 °C in the 14 days after the first dose, respectively. Overall, 1.9% EAEs were observed at 14 days and 0.4% at 28 days after the first/second dose administration. Conclusions: Data obtained from this study confirm the safety of the monovalent rotavirus vaccine even in preterm infants with gestational age ≥ 28 weeks, presenting an opportunity to improve the vaccination offer both in Sicily and in Italy by protecting the most fragile infants who are more at risk of contracting severe rotavirus gastroenteritis and nosocomial RV infection.

THE PROBLEM OF INCIDENCE OF ACUTE INTESTINAL INFECTIONS IN CHILDREN DURING WARTIME IN UKRAINE

The relevance of this pathology today is due to the increased incidence of acute intestinal infections in children. The purpose of our work was the analysis of modern views on the diagnosis and treatment of acute intestinal infections in children during the wartime period in Ukraine. Materials and methods: the data of the scientific literature were analyzed using the bibliosemantic method of research and a clinical case of the medical history was proposed, which caused some difficulties for the doctors at the initial stage. Research results and their discussion. The range of possible human etiological agents continues to expand as previously unknown viruses are isolated. The diseases caused by them are less studied, since their detection was carried out mainly in the framework of scientific research. The most frequent pathogens of intestinal infections are rotaviruses, enteroviruses, adenoviruses, and coronaviruses. Episodes of acute diarrheal diseases in European countries in children under 3 years of age were noted up to 2 times a year, but in countries with limited resources or military operations, on average, up to 6 times a year (in particular, in Ukraine by 2022). The war led to an increase in viral etiology and an increase in the share of children with secondary bacterial complications, and accordingly, the share of the use of antibacterial agents increased. The most common nosology of the gastrointestinal tract was acute gastroenterocolitis, which was characterized by any combination of diarrhea, fever, vomiting, and abdominal pain. Diarrhea is the second leading cause of child mortality in the world, especially in countries where there are military conflicts or a low social standard of living. The authors give an example of a clinical case of a girl, born in 2018, who was treated in the children's infectious disease department in the summer of 2022. and referred to persons forcibly resettled due to military operations.
 Isolation and identification of the causative agent usually takes at least 48 hours, and therefore the possibility of choosing a therapy decreases. Virological research in routine practice is rarely available due to the high cost of research. Therefore, it should be noted that there is immunoprophylaxis, in particular, of rotavirus infection. In the world, since 2006, vaccination has been introduced in more than 100 countries, which made it possible to significantly reduce the level of morbidity among children under 2 years of age. Two vaccines against rotavirus are registered in Ukraine. The first - is used in 2 doses at the age of 6 to 24 weeks, and the second - at the age of 6 to 32 weeks. Protection against severe rotavirus gastroenteritis is approximately 90-95%. But in our country, this vaccination is not yet included in the calendar of mandatory vaccinations. The authors give an example of a clinical case of a girl who was treated in the children's infectious disease department of the 1st Medical Center of Poltava in the summer of 2022.
 Conclusion. Thus, acute intestinal infections in childhood are a complex pathological process. Treatment should be timely, complex and justified from the etiopathogenetic point of view.

Transporting monovalent rotavirus vaccine efficacy estimates to an external target population: a secondary analysis of data from a randomised controlled trial in Malawi.

Oral rotavirus vaccine efficacy estimates from randomised controlled trials are highly variable across settings. Although the randomised study design increases the likelihood of internal validity of findings, results from trials may not always apply outside the context of the study due to differences between trial participants and the target population. Here, we used a weight-based method to transport results from a monovalent rotavirus vaccine clinical trial conducted in Malawi between 2005 and 2008 to a target population of all trial-eligible children in Malawi, represented by data from the 2015-2016 Malawi Demographic and Health Survey (DHS). We reweighted trial participants to reflect the population characteristics described by the Malawi DHS. Vaccine efficacy was estimated for 1008 trial participants after applying these weights such that they represented trial-eligible children in Malawi. We also conducted subgroup analyses to examine the heterogeneous treatment effects by stunting and tuberculosis vaccination status at enrolment. In the original trial, the estimates of one-year vaccine efficacy against severe rotavirus gastroenteritis and any-severity rotavirus gastroenteritis in Malawi were 49.2% (95% CI 15.6%-70.3%) and 32.1% (95% CI 2.5%-53.1%), respectively. After weighting trial participants to represent all trial-eligible children in Malawi, vaccine efficacy increased to 62.2% (95% CI 35.5%-79.0%) against severe rotavirus gastroenteritis and 38.9% (95% CI 11.4%-58.5%) against any-severity rotavirus gastroenteritis. Rotavirus vaccine efficacy may differ between trial participants and target populations when these two populations differ. Differences in tuberculosis vaccination status between the trial sample and DHS population contributed to varying trial and target population vaccine efficacy estimates.

581. Monovalent rotavirus vaccine efficacy against different rotavirus genotypes: a pooled analysis of Phase II and III trial data

Abstract Background Rotavirus vaccine effects appear lower in countries with high child mortality rates and high diversity of rotavirus genotypes. Some evidence suggests diminished vaccine efficacy (VE) against the G2P[4] genotype, which is heterotypic with existing monovalent rotavirus vaccine formulations. Most studies assessing genotype-specific VE have been underpowered and inconclusive. Methods We pooled individual-level data from ten Phase II and III clinical trials of monovalent rotavirus vaccine containing G1 and P[8] antigens (RV1). We estimated VE against any-severity and severe (Vesikari score ≥11) rotavirus gastroenteritis (RVGE) using binomial and multinomial logistic regression models for three types of VE: non-specific VE against any RVGE; genotype-specific VE against specific genotypes; and RV1-typic VE against genotypes homotypic, partially heterotypic, or fully heterotypic with the RV1 G1 and P[8] antigens. Models were adjusted for oral poliovirus vaccination concomitant with RV1 vaccination and the country’s child mortality stratum. Results A total of 87,644 infants from 22 countries in the Americas, Europe, Africa, and Asia were included in analysis. VE against severe RVGE was 91% (95% confidence interval (CI): 87-94%). Genotype-specific VE ranged from 96% (95% CI: 89-98%) against homotypic G1P[8] to 71% (95% CI: 43-85%) against fully-heterotypic G2P[4]. VE against severe RVGE caused by partially heterotypic genotypes (92% (95% CI: 84-96%)) was similar to VE against the homotypic genotype, but VE against fully heterotypic genotypes was lower (83% (95% CI: 67-91%)). VE against any-severity RVGE was 82% (95% CI: 75-87%). Genotype-specific VE estimates against any-severity RVGE ranged from 94% (95% CI: 86-97%) against G1P[8] to 63% (95% CI: 41-77%) against G2P[4]. VE against any-severity RVGE was lower (83% (95% CI: 72-90%) against partially heterotypic genotypes, but lowest (63% (95% CI: 40-77%)) against fully heterotypic genotypes. Conclusion RV1 VE is diminished against fully heterotypic genotypes including G2P[4]. Disclosures Benjamin Lopman, PhD, Epidemiological Research and Methods, LLC: Advisor/Consultant.

Systematic review of the effect of additional doses of oral rotavirus vaccine on immunogenicity and reduction in diarrhoeal disease among young children.

SummaryBackgroundOral rotavirus vaccines have lower effectiveness in high child mortality settings. We evaluated the impact of additional dose(s) schedules of rotavirus vaccine on vaccine immunogenicity and reduction in episodes of gastroenteritis.MethodsWe searched Medline (via PubMed), Cochrane databases and ClinicalTrials.gov for randomised controlled trials from 1973 to February 2022, evaluating the immunological and clinical impact of additional dose vs standard dose oral rotavirus vaccine schedules. We extracted immunogenicity – proportion of children with evidence of anti-rotavirus IgA seroresponse, and clinical – proportion of children with at least one episode of severe rotavirus gastroenteritis, outcome data and used random effects meta-analysis where appropriate. We assessed the methodological quality of the studies using the Cochrane risk of bias tool. The study protocol was registered in PROSPERO (CRD42021261058).FindingsWe screened 536 items and included 7 clinical trials. Our results suggest moderate to high level evidence that an additional dose rotavirus vaccine schedule improves IgA vaccine immune response, including additional doses administered as a booster dose schedule >6 months old; IgA vaccine seroresponse 74·3% additional dose schedule vs 56·1% standard dose schedule RR 1·3 (95%CI, 1·15 – 1·48), and when administered to children who were seronegative at baseline; IgA vaccine seroresponse 48.2% additional dose schedule vs 29.6% standard dose schedule RR 1.86 (95%CI 1.27 to 2.72). Only one study evaluated reduction in gastroenteritis episodes and found little benefit in first year of life, 1·8% vs 2·0% RR 0·88 (95% CI, 0·52 to 1·48), or second year of life, 1·7% vs 2·9% RR 0·62 (95%CI, 0·31 – 1·23).InterpretationAdministering an additional dose of oral rotavirus vaccines is likely to result in an improved vaccine immune response, including when administered as a booster dose to older children. Evidence of an impact on diarrhoeal disease is needed before additional dose rotavirus vaccine schedules can be recommended as vaccine policy.FundingBM was funded by the National Health and Medical Research Council, the Royal Australasian College of Physicians Paediatrics and Child Health Division, and the Australian Academy of Science.

Monovalent Rotavirus Vaccine Efficacy Against Different Rotavirus Genotypes: A Pooled Analysis of Phase II and III Trial Data.

Rotavirus vaccine performance appears worse in countries with high rotavirus genotype diversity. Evidence suggests diminished vaccine efficacy (VE) against G2P[4], which is heterotypic with existing monovalent rotavirus vaccine formulations. Most studies assessing genotype-specific VE have been underpowered and inconclusive. We pooled individual-level data from 10 Phase II and III clinical trials of rotavirus vaccine containing G1 and P[8] antigens (RV1) conducted between 2000 and 2012. We estimated VE against both any-severity and severe (Vesikari score ≥11) rotavirus gastroenteritis (RVGE) using binomial and multinomial logistic regression models for non-specific VE against any RVGE, genotype-specific VE, and RV1-typic VE against genotypes homotypic, partially heterotypic, or fully heterotypic with RV1 antigens. We adjusted models for concomitant oral poliovirus and RV1 vaccination and the country's designated child mortality stratum. Analysis included 87 644 infants from 22 countries in the Americas, Europe, Africa, and Asia. For VE against severe RVGE, non-specific VE was 91% (95% confidence interval [CI]: 87-94%). Genotype-specific VE ranged from 96% (95% CI: 89-98%) against G1P[8] to 71% (43-85%) against G2P[4]. RV1-typic VE was 92% (95% CI: 84-96%) against partially heterotypic genotypes but 83% (67-91%) against fully heterotypic genotypes. For VE against any-severity RVGE, non-specific VE was 82% (95% CI: 75-87%). Genotype-specific VE ranged from 94% (95% CI: 86-97%) against G1P[8] to 63% (41-77%) against G2P[4]. RV1-typic VE was 83% (95% CI: 72-90%) against partially heterotypic genotypes but 63% (40-77%) against fully heterotypic genotypes. RV1 VE is comparatively diminished against fully heterotypic genotypes including G2P[4].

Efficacy, safety and immunogenicity of hexavalent rotavirus vaccine in Chinese infants.

A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine (HRV) against rotavirus gastroenteritis (RVGE). A total of 6400 participants aged 6–12 weeks were enrolled and randomly assigned to either HRV (n ​= ​3200) or placebo (n ​= ​3200) group. All the subjects received three oral doses of vaccine four weeks apart. The vaccine efficacy (VE) against RVGE caused by rotavirus serotypes contained in HRV was evaluated from 14 days after three doses of administration up until the end of the second rotavirus season. VE against severe RVGE, VE against RVGE hospitalization caused by serotypes contained in HRV, and VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were also investigated. All adverse events (AEs) were collected for 30 days after each dose. Serious AEs (SAEs) and intussusception cases were collected during the entire study. Our data showed that VE against RVGE caused by serotypes contained in HRV was 69.21% (95%CI: 53.31–79.69). VE against severe RVGE and RVGE hospitalization caused by serotypes contained in HRV were 91.36% (95%CI: 78.45–96.53) and 89.21% (95%CI: 64.51–96.72) respectively. VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were 62.88% (95%CI: 49.11–72.92), 85.51% (95%CI: 72.74–92.30) and 83.68% (95%CI: 61.34–93.11). Incidences of AEs from the first dose to one month post the third dose in HRV and placebo groups were comparable. There was no significant difference in incidences of SAEs in HRV and placebo groups. This study shows that this hexavalent reassortant rotavirus vaccine is an effective, well-tolerated, and safe vaccine for Chinese infants.

Experience with the use of the drug cycloferon in the treatment of rotaviral infection in children

Introduction. Rotavirus infection is the leading cause of acute gastroenteritis in young children. Due to the lack of etiotropic treatment of viral gastroenteritis, the interest of scientists and practitioners in the use of antiviral drugs is increasing. Studies of domestic authors have proven that the low molecular weight interferon inductor – meglumine acridonacetate has antiviral, immunoregulatory and anti-inflammatory activity.Aim. Evaluation of the efficacy and safety of the antiviral drug meglumine acridonacenate in the treatment of acute gastroenteritis of rotavirus etiology in children aged 4–7 years in a hospital setting.Materials and methods. A prospective analysis of cases of treatment with meglumine acridonacetate for moderately severe rotavirus gastroenteritis in preschool children (n = 29, group I) was carried out. The comparison group consisted of patients receiving standard therapy (n = 31, group II). The presence of rotavirus infection was confirmed by the detection of the pathogen antigen in the feces. Meglumine acridonacetate was prescribed according to the scheme, parenterally, every other day.Results and discussion. The effectiveness of therapy with an antiviral drug on the 3rd day of treatment of moderately severe rotavirus gastroenteritis was 79.3% (p < 0.05). The elimination of the main clinical symptoms of the disease was noted on days 2–3: a decrease in the symptoms of intoxication, fever, a significant decrease in the duration of vomiting and diarrhea (p < 0.05), a reduction in the pathogen elimination period by 2.67 days (p < 0.01), meglumine acridonacetate was well tolerated, no side effects of the drug were detected.Conclusions. Meglumine acridonacetate can be recommended for the complex treatment of moderate rotavirus infection from the first days of the disease.

The efficacy and safety of rotavirus vaccines in countries in Africa and Asia with high child mortality

Rotavirus remains a leading cause of diarrhoeal morbidity and mortality in young children and rotavirus vaccines are critical for reducing global disease burden. This report addresses the performance of rotavirus vaccines in countries with high child mortality. We performed a sensitivity analysis as part of a systematic review on rotavirus vaccines to inform development of World Health Organization vaccine recommendations. The efficacy of four prequalified vaccines against severe rotavirus gastroenteritis was similar across high mortality settings in Asia and Africa. Within the first year following vaccination, vaccine efficacy for the four vaccines ranged from 48% to 57% while in the second year, efficacy ranged from 29% to 54%. The four vaccines showed no increase in intussusception risk in these settings. All four vaccines appear to prevent significant numbers of severe rotavirus gastroenteritis episodes with no measurable increase in intussusception risk in high mortality settings in Africa and Asia.

Neonatal rotavirus vaccine (RV3-BB) immunogenicity and safety in a neonatal and infant administration schedule in Malawi: a randomised, double-blind, four-arm parallel group dose-ranging study

SummaryBackgroundRotavirus vaccines reduce rotavirus-related deaths and hospitalisations but are less effective in high child mortality countries. The human RV3-BB neonatal G3P[6] rotavirus vaccine administered in a neonatal schedule was efficacious in reducing severe rotavirus gastroenteritis in Indonesia but had not yet been evaluated in African infants.MethodsWe did a phase 2, randomised, double-blind, parallel group dose-ranging study of three doses of oral RV3-BB rotavirus vaccine in infants in three primary health centres in Blantyre, Malawi. Healthy infants less than 6 days of age with a birthweight 2·5 to 4·0 kg were randomly assigned (1:1:1:1) into one of four treatment groups: neonatal vaccine group, which included high-titre (1·0 × 107 focus-forming unit [FFU] per mL), mid-titre (3·0 × 106 FFU per mL), or low-titre (1·0 × 106 FFU per mL); and infant vaccine group, which included high-titre (1·0 × 107 FFU per mL) using a computer generated code (block size of four), stratified by birth (singleton vs multiple). Neonates received their three doses at 0–5 days to 10 weeks and infants at 6–14 weeks. Investigators, participant families, and laboratory staff were masked to group allocation. Anti-rotavirus IgA seroconversion and vaccine take (IgA seroconversion and stool shedding) were evaluated. Safety was assessed in all participants who received at least one dose of vaccine or placebo. The primary outcome was the cumulative IgA seroconversion 4 weeks after three doses of RV3-BB in the neonatal schedule in the high-titre, mid-titre, and low-titre groups in the per protocol population, with its 95% CI. With the high-titre group as the active control group, we did a non-inferiority analysis of the proportion of participants with IgA seroconversion in the mid-titre and low-titre groups, using a non-inferiority margin of less than 20%. This trial is registered at ClinicalTrials.gov (NCT03483116).FindingsBetween Sept 17, 2018, and Jan 27, 2020, 711 participants recruited were randomly assigned into four treatment groups (neonatal schedule high titre n=178, mid titre n=179, low titre n=175, or infant schedule high titre n=179). In the neonatal schedule, cumulative IgA seroconversion 4 weeks after three doses of RV3-BB was observed in 79 (57%) of 139 participants in the high-titre group, 80 (57%) of 141 participants in the mid-titre group, and 57 (41%) of 138 participants in the low-titre group and at 18 weeks in 100 (72%) of 139 participants in the high-titre group, 96 (67%) of 143 participants in the mid-titre group, and 86 (62%) of 138 of participants in the low-titre. No difference in cumulative IgA seroconversion 4 weeks after three doses of RV3-BB was observed between high-titre and mid-titre groups in the neonatal schedule (difference in response rate 0·001 [95%CI −0·115 to 0·117]), fulfilling the criteria for non-inferiority. In the infant schedule group 82 (59%) of 139 participants had a cumulative IgA seroconversion 4 weeks after three doses of RV3-BB at 18 weeks. Cumulative vaccine take was detected in 483 (85%) of 565 participants at 18 weeks. Three doses of RV3-BB were well tolerated with no difference in adverse events among treatment groups: 67 (39%) of 170 participants had at least one adverse event in the high titre group, 68 (40%) of 172 participants had at least one adverse event in the mid titre group, and 69 (41%) of 169 participants had at least one adverse event in the low titre group.InterpretationRV3-BB was well tolerated and immunogenic when co-administered with Expanded Programme on Immunisation vaccines in a neonatal or infant schedule. A lower titre (mid-titre) vaccine generated similar IgA seroconversion to the high-titre vaccine presenting an opportunity to enhance manufacturing capacity and reduce costs. Neonatal administration of the RV3-BB vaccine has the potential to improve protection against rotavirus disease in children in a high-child mortality country in Africa.FundingBill & Melinda Gates Foundation, Australian Tropical Medicine Commercialisation Grant.

Enteric virome negatively affects seroconversion following oral rotavirus vaccination in a longitudinally sampled cohort of Ghanaian infants

SummaryRotavirus vaccines (RVVs) have substantially diminished mortality from severe rotavirus (RV) gastroenteritis but are significantly less effective in low- and middle-income countries (LMICs), limiting their life-saving potential. The etiology of RVV’s diminished effectiveness remains incompletely understood, but the enteric microbiota has been implicated in modulating immunity to RVVs. Here, we analyze the enteric microbiota in a longitudinal cohort of 122 Ghanaian infants, evaluated over the course of 3 Rotarix vaccinations between 6 and 15 weeks of age, to assess whether bacterial and viral populations are distinct between non-seroconverted and seroconverted infants. We identify bacterial taxa including Streptococcus and a poorly classified taxon in Enterobacteriaceae as positively correlating with seroconversion. In contrast, both bacteriophage diversity and detection of Enterovirus B and multiple novel cosaviruses are negatively associated with RVV seroconversion. These findings suggest that virome-RVV interference is an underappreciated cause of poor vaccine performance in LMICs.

Plasma Rotavirus-specific IgA and Risk of Rotavirus Vaccine Failure in Infants in Malawi.

BackgroundRotavirus vaccine efficacy is reduced in low-income populations, but efforts to improve vaccine performance are limited by lack of clear correlates of protection. While plasma rotavirus (RV)-specific IgA appears strongly associated with protection against rotavirus gastroenteritis in high-income countries, weaker association has been observed in low-income countries. We tested the hypothesis that lower RV-specific IgA is associated with rotavirus vaccine failure in Malawian infants.MethodsIn a case-control study we recruited infants presenting with severe rotavirus gastroenteritis following monovalent oral rotavirus vaccination (RV1 vaccine failures). Conditional logistic regression was used to determine the odds of rotavirus seronegativity (RV-specific IgA<20 U/mL) in these cases compared 1:1 with age-matched, vaccinated, asymptomatic community controls. Plasma RV-specific IgA was determined by ELISA for all participants at recruitment, and for cases at 10 days post symptom onset. Rotavirus infection and genotype were determined by antigen testing and RT-PCR respectively.ResultsIn 116 age-matched pairs, infants with RV1 vaccine failure were more likely to be RV-specific IgA seronegative than controls: OR 3.1 (95%CI 1.6-5.9), p=0.001. In 60 infants with convalescent serology, 42/45 (93%, 95%CI 81-98%) infants seronegative at baseline became seropositive. Median rise in RV-specific IgA concentration following acute infection was 112.8 (IQR 19.1-380.6) fold.ConclusionsIn this vaccinated population with high residual burden of rotavirus disease, RV1 vaccine failure was associated with lower RV-specific IgA, providing further evidence of RV-specific IgA as a marker of protection. Robust convalescent RV-specific IgA response in vaccine failures suggests differences in wild-type and vaccine-induced immunity, which informs future vaccine development.

The Study of Parents’ Convictions and Attitudes to the Vaccination Against Rotavirus Gastroenteritis in Ukraine

Rotavirus Gastroenteritis (RVGE) is one of the most frequent causes of diarrhea in children that can lead to severe dehydration. Specific etiotropic therapy of RVGE is absent but the disease can be prevented by vaccination that is recommended by WHO for inclusion in all national programs. In Ukraine, vaccination against RVGE is non-mandatory; whereas peoples’ confidence in vaccination is low. The objective: the study aimed to investigate parents’ awareness about RVGE and rotavirus vaccines, positive and negative influencers on having their babies getting vaccinated against RVGE and sources of information. Materials and methods. This qualitative study included structured discussions with parents of children less than 5 years old. The parents were distributed into six groups based on criteria of RVGE presence/absence in medical history and place of residence (large city, medium-sized city, and village). Descriptive thematic analysis of discussions using verbatim transcripts in Microsoft Word files was conducted using MAXQDA qualitative data analysis software. Results. The majority of parents are aware about RVGE. The sources of this knowledge are; internet, experience from other parents, and communication with healthcare practitioners (including nurses). The level of knowledge about rotavirus vaccine is low and the majority of parents learned about it after their children were too old to receive the vaccine. Parents whose children have experienced severe RVGE doubt that they would vaccinate their children, even if they knew about the existence of a vaccine prior to the disease. The causes of such doubts are lack of trust in healthcare practitioners and non-mandatory status of the vaccine. Conclusions. Informing parents about RVGE vaccination, when the child is too old to receive it, appears to be the main barrier. Additional barriers include the overall lack of information about vaccination, the unavailability of the vaccine against RVGE, and the need to pay for it due to its non-mandatory status.

Detection and Clinical Implications of Monovalent Rotavirus Vaccine-Derived Virus Strains in Children with Gastroenteritis in Alberta, Canada.

While rotavirus vaccine programs effectively protect against severe rotavirus gastroenteritis, rotavirus vaccine strains have been identified in the stool of vaccinated children and their close contacts suffering from acute gastroenteritis. The prevalence of vaccine strains, the emergence of vaccine-derived strains, and their role in acute gastroenteritis are not well studied. We developed a locked nucleic acid reverse transcription real-time PCR assay (LNA-RTqPCR) to detect the monovalent rotavirus vaccine (RV1) Rotarix nonstructural protein 2 (NSP2) in children with acute gastroenteritis and healthy controls, and validated it using sequence-confirmed RV1 strains. The association between RV1-derived strains and gastroenteritis was determined using logistic regression. The new assay exhibited 100% (95% CI 91.7%, 100%) diagnostic sensitivity and 99.4% (95% CI 96.2%, 100%) diagnostic specificity, with a detection limit of 9.86 copies/reaction and qPCR efficiency of 99.7%. Using this assay, we identified the presence of RV1-derived NSP2 sequences in 7.7% of rotavirus gastroenteritis cases and 98.6% of rotavirus-positive healthy children (94.4% had previously received the RV1). Among gastroenteritis cases, those whose stool contained RV1-derived strains had milder gastroenteritis symptoms compared to that of natural rotavirus infections. We observed no significant association between RV1-derived strains and gastroenteritis (odds ratio [OR] 0.98; 95% CI 0.60, 1.72). Our study demonstrated that the new assay is suitable for monitoring RV1-derived rotavirus strain circulation and that the RV1-derived strains are not associated with development of gastroenteritis symptoms.

Rotavirus vaccine efficacy up to 2 years of age and against diverse circulating rotavirus strains in Niger: Extended follow-up of a randomized controlled trial.

BackgroundRotavirus vaccination is recommended in all countries to reduce the burden of diarrhea-related morbidity and mortality in children. In resource-limited settings, rotavirus vaccination in the national immunization program has important cost implications, and evidence for protection beyond the first year of life and against the evolving variety of rotavirus strains is important. We assessed the extended and strain-specific vaccine efficacy of a heat-stable, affordable oral rotavirus vaccine (Rotasiil, Serum Institute of India, Pune, India) against severe rotavirus gastroenteritis (SRVGE) among healthy infants in Niger.Methods and findingsFrom August 2014 to November 2015, infants were randomized in a 1:1 ratio to receive 3 doses of Rotasiil or placebo at approximately 6, 10, and 14 weeks of age. Episodes of gastroenteritis were assessed through active and passive surveillance and graded using the Vesikari score. The primary endpoint was vaccine efficacy of 3 doses of vaccine versus placebo against a first episode of laboratory-confirmed SRVGE (Vesikari score ≥ 11) from 28 days after dose 3, as previously reported. At the time of the primary analysis, median age was 9.8 months. In the present paper, analyses of extended efficacy were undertaken for 3 periods (28 days after dose 3 to 1 year of age, 1 to 2 years of age, and the combined period 28 days after dose 3 to 2 years of age) and by individual rotavirus G type. Among the 3,508 infants included in the per-protocol efficacy analysis (mean age at first dose 6.5 weeks; 49% male), the vaccine provided significant protection against SRVGE through the first year of life (3.96 and 9.98 cases per 100 person-years for vaccine and placebo, respectively; vaccine efficacy 60.3%, 95% CI 43.6% to 72.1%) and over the entire efficacy follow-up period up to 2 years of age (2.13 and 4.69 cases per 100 person-years for vaccine and placebo, respectively; vaccine efficacy 54.7%, 95% CI 38.1% to 66.8%), but the difference was not statistically significant in the second year of life. Up to 2 years of age, rotavirus vaccination prevented 2.56 episodes of SRVGE per 100 child-years. Estimates of efficacy against SRVGE by individual rotavirus genotype were consistent with the overall protective efficacy. Study limitations include limited generalizability to settings with administration of oral polio virus due to low concomitant administration, limited power to assess vaccine efficacy in the second year of life owing to a low number of events among older children, potential bias due to censoring of placebo children at the time of study vaccine receipt, and suboptimal adapted severity scoring based on the Vesikari score, which was designed for use in settings with high parental literacy.ConclusionsRotasiil provided protection against SRVGE in infants through an extended follow-up period of approximately 2 years. Protection was significant in the first year of life, when the disease burden and risk of death are highest, and against a changing pattern of rotavirus strains during the 2-year efficacy period. Rotavirus vaccines that are safe, effective, and protective against multiple strains represent the best hope for preventing the severe consequences of rotavirus infection, especially in resource-limited settings, where access to care may be limited. Studies such as this provide valuable information for the planning of national immunization programs and future vaccine development.Trial registrationClinicalTrials.gov NCT02145000.

Association of Rotavirus Vaccines With Reduction in Rotavirus Gastroenteritis in Children Younger Than 5 Years

Rotavirus vaccines have been introduced worldwide, and the clinical association of different rotavirus vaccines with reduction in rotavirus gastroenteritis (RVGE) after introduction are noteworthy. To evaluate the comparative benefit, risk, and immunogenicity of different rotavirus vaccines by synthesizing randomized clinical trials (RCTs) and observational studies. Relevant studies published in 4 databases: Embase, PubMed, the Cochrane Library, and Web of Science were searched until July 1, 2020, using search terms including "rotavirus" and "vaccin*." Randomized clinical trials and cohort and case-control studies involving more than 100 children younger than 5 years that reported the effectiveness, safety, or immunogenicity of rotavirus vaccines were included. A random-effects model was used to calculate relative risks (RRs), odds ratios (ORs), risk differences, and 95% CIs. Adjusted indirect treatment comparison was performed to assess the differences in the protection of Rotarix and RotaTeq. The primary outcomes were RVGE, severe RVGE, and RVGE hospitalization. Safety-associated outcomes involved serious adverse events, intussusception, and mortality. A meta-analysis of 20 RCTs and 38 case-control studies revealed that Rotarix (RV1) significantly reduced RVGE (RR, 0.316 [95% CI, 0.224-0.345]) and RVGE hospitalization risk (OR, 0.347 [95% CI, 0.279-0.432]) among children fully vaccinated; RotaTeq (RV5) had similar outcomes (RVGE: RR, 0.350 [95% CI, 0.275-0.445]; RVGE hospitalization risk: OR, 0.272 [95% CI, 0.197-0.376]). Rotavirus vaccines also demonstrated higher protection against severe RVGE. Additionally, no significant differences in the protection of RV1 and RV5 against rotavirus disease were noted in adjusted indirect comparisons. Moderate associations were found between reduced RVGE risk and Rotavac (RR, 0.664 [95% CI, 0.548-0.804]), Rotasiil (RR, 0.705 [95% CI, 0.605-0.821]), and Lanzhou lamb rotavirus vaccine (RR, 0.407 [95% CI, 0.332-0.499]). All rotavirus vaccines demonstrated no risk of serious adverse events. A positive correlation was also found between immunogenicity and vaccine protection (eg, association of RVGE with RV1: coefficient, -1.599; adjusted R2, 99.7%). The high protection and low risk of serious adverse events for rotavirus vaccines in children who were fully vaccinated emphasized the importance of worldwide introduction of rotavirus vaccination. Similar protection provided by Rotarix and RotaTeq relieves the pressure of vaccines selection for health care authorities.

Developing a manufacturing process to deliver a cost effective and stable liquid human rotavirus vaccine

Despite solid evidence of the success of rotavirus vaccines in saving children from fatal gastroenteritis, more than 82 million infants worldwide still lack access to a rotavirus vaccine. The main barriers to global rotavirus vaccine coverage include cost, manufacturing capacity and suboptimal efficacy in low- and lower-middle income countries. One vaccine candidate with the potential to address the latter is based on the novel, naturally attenuated RV3 strain of rotavirus, RV3-BB vaccine administered in a birth dose strategy had a vaccine efficacy against severe rotavirus gastroenteritis of 94% at 12 months of age in infants in Indonesia. To further develop this vaccine candidate, a well-documented and low-cost manufacturing process is required. A target fully loaded cost of goods (COGs) of ≤$3.50 per course of three doses was set based on predicted market requirements. COGs modelling was leveraged to develop a process using Vero cells in cell factories reaching high titers, reducing or replacing expensive reagents and shortening process time to maximise output. Stable candidate liquid formulations were developed allowing two-year storage at 2–8 °C. In addition, the formulation potentially renders needless the pretreatment of vaccinees with antacid to ensure adequate gastric acid neutralization for routine oral vaccination. As a result, the formulation allows small volume dosing and reduction of supply chain costs. A dose ranging study is currently underway in Malawi that will inform the final clinical dose required. At a clinical dose of ≤6.3 log10 FFU, the COGs target of ≤$3.50 per three dose course was met. At a clinical dose of 6.5 log10 FFU, the final manufacturing process resulted in a COGs that is substantially lower than the current average market price, 2.44 USD per dose. The manufacturing and formulation processes were transferred to BioFarma in Indonesia to enable future RV3-BB vaccine production.

Severe rotavirus gastroenteritis in children older than 5 years after vaccine introduction

IntroductionRotavirus (RV) is the major pathogen responsible for acute gastroenteritis in infants. Since RV vaccines were introduced, a substantial decline in the incidence of severe RV infection has been reported. However, some burden still exists, even in developed countries, including Japan. MethodsWe retrospectively surveyed 380 patients hospitalized for acute gastroenteritis from 2015 to 2019. In 2019, additional detailed clinical information of 21 patients with RV gastroenteritis was obtained to evaluate the efficacy of the RV vaccine. Nine fecal samples from those patients were collected to detect the RV genotypes. ResultsOur data showed an increasing trend in hospitalizations for severe RV gastroenteritis in children older than 5 years. According to the Vesikari clinical severity scores in the older group (≥5 years), the gastrointestinal symptoms in vaccinated patients were less severe than those in unvaccinated patients (p = 0.014). The genotype analysis revealed that G9P[8]I1 was the major genotype in the recruited patients in 2019. ConclusionsThis report warns that children older than 5 years could be affected by severe RV infection and suggests prompt intervention for this age group, similar to that in infants. In the new period in which the RV vaccine is included in Japanese national immunization programs beginning October 2020, continuous monitoring of patient clinical characteristics and RV epidemiology is required to determine the role of vaccines.

Meta-analysis of the effectiveness of pentavalent live oral vaccine for the prevention of severe forms of rotavirus gastroenteritis in children

Rotavirus infection is ubiquitously distributed and represents a global public health problem. Some studies showed that vaccination with pentavalent oral live vaccine was effective in prevention of severe forms of rotavirus gastroenteritis among children up to 3 years of age. Previous randomized placebo-controlled studies assessing this issue were repeatedly conducted. However, due to the features of the epidemiology of pediatric rotavirus infection in Russia, a metaanalysis was conducted in the risk group — children under the age of 3 years by administering a full vaccination course for a single vaccine registered in the Russian Federation. A search was performed by two independent reviewers covering 1994 to February 2019, without restrictions on language, in five databases on medical and biological publications: Russian Science Citation Index, PubMed, Web of Science, MEDLINE, Scopus, and in contents of thematic journals and bibliographic lists. The meta-analysis included multicenter randomized controlled trials comparing the efficacy of placebo and completed full vaccination course with pentavalent live oral rotavirus vaccine in children under 3 years of age. The primary endpoint of the study was the incidence of severe gastroenteritis among children according to the Vesikari evaluation system. Data processing and generation of forest-plots to evaluate summarized results were carried out by the RevMan 5.3 free software distributed on the Cochrane Community website. The implementation of the “trim and fill” method was performed by using Stata 14.2 software. The meta-analysis consisted of 7 original publications performed as multicenter randomized, placebo-controlled double-blind studies. In the experimental and control group there were enrolled 19,384 and 19,425 subjects, respectively. Three-dose vaccination protocol markedly reduced a risk of infection with severe rotavirus gastroenteritis in the experimental group compared to control group, the odds ratio was 0.34 [95%, CI 0.19—0.60]. Cluster analysis also confirmed the protective effect of the full vaccination course. Group assessment of the vaccination effectiveness against rotavirus infection in countries of Africa and Southeast Asia showed significant protection, the odds ratio was 0.60 [95%, CI 0.52—0.70]. While evaluating the effectiveness of vaccination against rotavirus infection in Finland, the odds ratio was set at the level of statistical significance and reached 0.07 [95%, CI 0.04—0.11]. Thus, a full vaccination course with pentavalent live oral vaccine against rotavirus infection lowers a risk of developing severe rotavirus gastroenteritis in young children.