Impact and effectiveness of RotaTeq® vaccine based on 3 years of surveillance following introduction of a rotavirus immunization program in Finland

In silico identification of cyclosporin derivatives as potential inhibitors for RdRp of rotavirus by molecular docking and molecular dynamic studies

Rotavirus is one of the most common gastrointestinal viral diseases. Till date, there are only two vaccines available in the markets, which are specifically to be administered to young babies. In this study, VP1 RdRp is selected as potential target to carry out inhibitory activities. Cyclosporin A (Cys A) derivatives were designed via FBDD, pharmacokinetics, molecular docking, molecular dynamics (MD) simulation and molecular mechanics generalized born surface area was applied on these compounds. The results from these investigations were analyzed and it was found that the considered derivatives in this study were nontoxic and docking results revealed that the derivatives made some important bonds inside the active site of the receptors within a catalytic triad (Serine-Histidine-Aspartate). After analyzing the mean values of root mean square density (RMSD), root mean square fluctuation (RMSF), radius of gyration (RoG) and solvent accessible surface area (SASA) at 100 ns MD simulation of the selected compounds, it was found that compound 1 exhibits RMSD of 0.74 ± 0.10 Å, RMSF of 0.85 ± 0.15 Å, RoG of 16.45 ± 0.40 Å, SASA of 66.55 ± 0.35 nm2 and ΔGbind of -32.76 ± 0.02 kcal/mol. Therefore, the study revealed that amongst the designed and reported compounds, compound 1 was more stable within the active region of the RdRp and also this compound possesses lower binding free energy as compared to other selected compounds and Cys A as well.Communicated by Ramaswamy H. Sarma.

Incidence of Rotavirus-Related Hospitalizations in an Italian Southern Region from 2015 to 2021

(1) Background: Rotavirus is one of the leading causes of severe diarrhea and dehydration in infants and young children worldwide. The economic and social burden of rotavirus-related hospitalizations, particularly among children, remains a pressing concern for healthcare systems across the globe. Healthcare infrastructure and access to medical care can vary significantly within the region. Differences in the availability of healthcare facilities and the quality of care may influence the management and outcomes of rotavirus cases. (2) Methods: This was a retrospective study performed in the Abruzzo region, Italy. The study considered all hospitalization due to rotavirus gastroenteritis that occurred in the Abruzzo region from the year 2015 to 2021. Data were extracted from the hospital discharge records. The trend in hospital admissions, hospitalization costs and length of stay were evaluated and analyzed. (3) Results: A total of 664 admissions were reported during the study period. The incident rate grew till year 2019 with an annual percentage change of +13.9% (95%CI 12.6-15.2, p < 0.001). During the pandemic years, the incident rate showed a significant decrease with an annual percentage change of 12.5% (95%CI 15.5-9.3, p = 0.004). The length of stay of admissions was significantly higher among patients aged less than 1 year. (4) Conclusions: Rotavirus admission represents a heavy burden even in a high-income country such as Italy. These findings have the potential to inform targeted public health interventions, including vaccination strategies, and improve the overall well-being of children.

Сost-effectiveness of pentavalent rotavirus vaccination in the Russian Federation

   One of the main causes of acute gastroenteritis in children under 5 years of age is rotavirus infection (RVI). Vaccines against RVI significantly reduce the incidence.   Aim. To evaluate the cost-effectiveness of mass vaccination of children with a 5-valent RVI vaccine in the Russian Federation.   Materials and methods. The assessment was carried out using modeling based on published data on the effectiveness of the vaccine and epidemiological indicators in the Russian Federation. The analysis was carried out from the perspective of the health care system and society as a whole with a 5-year horizon. The cost of RVI therapy corresponded to the compulsory health insurance tariffs for St. Petersburg for 2022, the price of 1 dose of the vaccine was the registered price, including VAT. Costs and life expectancy, taking into account quality, were discounted at 3.5 % per year.   Results. Given the assumptions made, routine vaccination will prevent an average of 468,637 cases of RVI over 5 years. Avoided direct medical costs, i. e. RVI treatment costs will amount to 53,4 %, and lost income due to temporary disability – 46,6 % of the total avoided costs. At the same time, the volume of avoided costs is 61,4 % due to a decrease in morbidity in the vaccinated population, and 38.6 % due to the development of a indirect effect. The predicted avoided costs per 1 vaccinated person is 2,975 thousand rubles. From a societal perspective, the cost-effectiveness of the Rota-V-Aid vaccine will be 364,813 thousand rubles / QALY (quality-adjusted life year), and from a healthcare perspective – 1726,399 thousand rubles / QALY. Thus, in both cases, the cost-effectiveness of RVI vaccination will not exceed the generally accepted threshold of willingness to pay, equal to three times the gross domestic product per capita in the Russian Federation (according to data for 2021 – ~2,7 million rubles). The predicted cost-effectiveness of selective vaccination is significantly lower than that of mass vaccination.   Conclusions. Mass vaccination of children with a 5-valent vaccine against RVI will not only reduce the incidence in the Russian Federation, but, taking into account the assumptions made, can also be considered as a cost-effective intervention.

Real-world impact of rotavirus vaccination in European healthcare settings: a systematic literature review

INTRODUCTION

Rotavirus is one of the most common pathogens causing diarrhea in children <5 years and has a major impact on childhood morbidity and mortality. Since the implementation of rotavirus vaccines into childhood immunization programs across Europe, there has been a reduction in rotavirus burden, including hospitalizations, outpatient cases, costs, and deaths.

AREAS COVERED

A systematic literature review identified publications describing the clinical and economic impact of rotavirus vaccinations across Europe, from their introduction in 2006 to the end of 2020. A total of 3,137 articles were identified, of which 46 were included in the review. Included articles reported the impact of rotavirus vaccination on disease in any age group.

EXPERT OPINION

Rotavirus vaccination has resulted in substantial reductions in hospitalizations and rotavirus-associated costs across Europe, particularly in children <5 years. There is some evidence of herd protection afforded to older age groups where vaccine uptake is high among infants, highlighting the potential for vaccination to confer a greater societal benefit as programs become more established. Increasing vaccination coverage and continuing investment in widespread rotavirus vaccination programs across countries will likely increase the substantial public health benefits associated with vaccination and further reduce the clinical and economic burden of disease.

Regional hospitalisation and seasonal variations of Pediatric rotavirus gastroenteritis pre- and post-RV vaccination: a prospective and retrospective study

BACKGROUND

Rotavirus is the primary cause of gastroenteritis in children worldwide and is a leading cause of gastroenteritis in children, with a significant burden. Rotavirus vaccine became available in Ireland in 2016. This study aimed to investigate hospital admissions and seasonal characteristics of rotavirus gastroenteritis in a pre- and post-vaccination period in a single district general hospital.

METHODS

In the post-vaccination year, from November 18th 2016 to November 18th 2017, all children up to 3 years of age who presented to Mayo University Hospital with vomiting and diarrhea, were recruited and had their stool tested for rotavirus. Retrospective analysis of hospital data of children of the same age during pre-vaccination years (2014-2016) were used for comparison.

RESULTS

Compared with the pre-vaccination years (2014-2016), the median percentages of reduction of rotavirus positive stool requests and hospital admissions were high, 48.5% and 73%, respectively. In the post-vaccination year, the median percentage of reduction of emergency department presentation (stool requests) with gastroenteritis was 9%. No delay in the onset of RV season or reduction of the peak of RV infection was noted in the post-vaccination year. The duration of rotavirus season in 2016/2017 was short.

CONCLUSIONS

Compared with 3 pre-vaccination years, the total number of gastroenteritis presentations, gastroenteritis hospital admissions, and rotavirus positive gastroenteritis cases were all reduced, and the duration of the rotavirus season was shorter.

Community-level interventions for mitigating the risk of waterborne diarrheal diseases: a systematic review

BACKGROUND

Waterborne diarrhea diseases are among the leading causes of morbidity and mortality globally. These diseases can be mitigated by implementing various interventions. We reviewed the literature to identify available interventions to mitigate the risk of waterborne diarrheal diseases.

METHODS

We conducted a systematic database review of CINAHL (Cumulative Index to Nursing and Allied Health Literature), PubMed, Web of Science Core Collection, Cochrane library, Scopus, African Index Medicus (AIM), and LILACS (Latin American and Caribbean Health Sciences Literature). Our search was limited to articles published between 2009 and 2020. We conducted the review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement checklist. The identified studies were qualitatively synthesized.

RESULTS

Our initial search returned 28 773 articles of which 56 studies met the inclusion criteria. The included studies reported interventions, including vaccines for rotavirus disease (monovalent, pentavalent, and Lanzhou lamb vaccine); enhanced water filtration for preventing cryptosporidiosis, Vi polysaccharide for typhoid; cholera 2-dose vaccines, water supply, water treatment and safe storage, household disinfection, and hygiene promotion for controlling cholera outbreaks.

CONCLUSION

We retrieved few studies on interventions against waterborne diarrheal diseases in low-income countries. Interventions must be specific to each type of waterborne diarrheal disease to be effective. Stakeholders must ensure collaboration in providing and implementing multiple interventions for the best outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020190411 .

Impact analysis of rotavirus vaccination in various geographic regions in Western Europe

BACKGROUND

Universal mass vaccination (UMV) against rotavirus has been implemented in many but not all European countries. This study investigated the impact of UMV on rotavirus incidence trends by comparing European countries with UMV: Belgium, England/Wales and Germany versus countries without UMV: Denmark and the Netherlands.

METHODS

For this observational retrospective cohort study, time series data (2001-2016) on rotavirus detections, meteorological factors and population demographics were collected. For each country, several meteorological and population factors were investigated as possible predictors of rotavirus incidence. The final set of predictors were incorporated in negative binomial models accounting for seasonality and serial autocorrelation, and time-varying incidence rate ratios (IRR) were calculated for each age group and country separately. The overall vaccination impact two years after vaccine implementation was estimated by pooling the results using a random effects meta-analyses. Independent t-tests were used to compare annual epidemics in the pre-vaccination and post-vaccination era to explore any changes in the timing of rotavirus epidemics.

RESULTS

The population size and several meteorological factors were predictors for the rotavirus epidemiology. Overall, we estimated a 42% (95%-CI 23;56%) reduction in rotavirus incidence attributable to UMV. Strongest reductions were observed for age-groups 0-, 1- and 2-years (IRR 0.47, 0.48 and 0.63, respectively). No herd effect induced by UMV in neighbouring countries was observed. In all UMV countries, the start and/or stop and corresponding peak of the rotavirus season was delayed by 4-7 weeks.

CONCLUSIONS

The introduction of rotavirus UMV resulted in an overall reduction of 42% in rotavirus incidence in Western European countries two years after vaccine introduction and caused a change in seasonal pattern. No herd effect induced by UMV neighbouring countries was observed for Denmark and the Netherlands.

Is the Rotavirus Vaccine Really Associated with a Decreased Risk of Developing Celiac and Other Autoimmune Diseases?

This review examines the risk of developing celiac disease (CD) and other autoimmune diseases in individuals receiving the rotavirus (RV) vaccine compared to the normal population. Celiac disease is a malabsorptive, chronic, immune-mediated enteropathy involving the small intestine. The pathogenesis of CD is multifactorial, and mucosal immunity plays an important role in its development. Low mucosal IgA levels significantly increase the risk of developing the disease. Rotavirus is an infectious agent that causes diarrhea, particularly in children aged 0-24 months, and is frequently involved in diarrhea-related deaths in these children. An oral vaccine against RV has been developed. While it is effective on RV infection, it also contributes to increasing mucosal immunity. Studies have indicated that individuals immunized with the RV vaccine are at lower risk of developing CD than unvaccinated individuals. In addition, the mean age for developing CD autoimmunity may be higher in the vaccinated group than in controls receiving placebo. Additional studies that include children immunized with different RV vaccines and unvaccinated children would provide more meaningful results. Although current data suggest a possible association of RV vaccination with a reduced risk of developing CD and other autoimmune diseases, this remains an unanswered question that merits greater international investigation.

Effectiveness of rotavirus vaccine in the prevention of diarrhoeal diseases among children under age five years in Kavango East and West Regions, Namibia

Background

Diarrheal diseases due to rotavirus infection contribute greatly to morbidity and mortality rates of babies and young children in many developing countries. This public health concern can effectively be reduced by the use of the rotavirus vaccine, though there is an anecdotal evidence indicating that despite introduction of the vaccine the number of cases of diarrhoea diseases are still high in Namibia, particularly in Kavango east and west regions.

Objective

This study evaluated the effectiveness of the rotavirus vaccine in preventing diarrhoea cases among children under age five years in Kavango regions.

Methods

The study employed a quasiexperimental design comparing diarrhoea cases before (2010-2013) and after (2014-2017) introduction of the rotavirus vaccine among children under age five years. Data were extracted from District Health Information System version 2 and analysed by using one way analysis of covariance.

Results

Before introduction of the rotavirus vaccine, there were 14 500 diarrhoea cases, which is 1.6% rate of infection. After introduction of the rotavirus vaccine, there were 14 400 diarrhoea cases, which is 1.58% rate of infection. This is supported by the effect size (partial eta²) of 0.01%, which is very small. The trend of diarrhoea cases after rotavirus vaccine introduction fluctuated with no major decline of diarrhoea cases.

Conclusions

The study concluded that rotavirus vaccine is less effective in preventing diarrhoea diseases among children under age five years in the Kavango regions. Further research is needed to substantiate these findings as other factors can contribute to fluctuation of diarrhoea cases.

Effectiveness of the oral human attenuated pentavalent rotavirus vaccine (RotaTeq™) postlicensure: a meta-analysis-2006-2020

BACKGROUND

Rotavirus (RV), which causes RV-associated gastroenteritis (RVGE), has accounted for considerable morbidity. We aimed to assess the effectiveness (VE) of the oral pentavalent RV vaccine (RotaTeq™) in real-world settings in children and infants with gastroenteritis.

METHODS

We performed a systematic search for peer-reviewed studies published between 1 January 2006 and 1 May 2020 and a meta-analysis to calculate the VE of RotaTeq™ vaccine. The primary outcome was the pooled three-dose vaccine VE. Stratified analysis of the vaccine VEs was performed according to dosages, study design, population age, socioeconomic status (SES), introduction condition, control group types, outcomes of RV disease, and RV strains.

RESULTS

After screening 2359 unique records, 28 studies were included and meta-analyzed. The overall VE estimate was 84% (95% confidence interval [CI], 80-87%). Stratified analyses revealed a nonnegligible impact of factors such as study design and SES. Other factors did not show great impart to VE with no significant differences between groups.

CONCLUSIONS

RotaTeq™ is effective against RV infection, especially in high-income countries. Adopting suitable study methods and expansion of RV surveillance in low-income regions is crucial to assess VE in real-life settings and provide feasible vaccine regimens to improve vaccine VE.

Prevalence of Rotaviruses in the Etiology of Acute Diarrhea in Young Children, Clinical forms, Extraintestinal Manifestations and Complications

Rotavirus is highly contagious factor with dominant feces-oral transmission. Because it is stable in external environment, transmission clusters are possible by close contact, ingestion of contaminated water or food or contact with contaminated surfaces. It survives within hours and days on hands and contaminated surfaces. This makes it the most common enteric and nosocomial pathogen in the world, especially in early childhood. In addition to the rapid dehydration with pronounced electrolyte disturbances, numerous extraintestinal possibilities have been recorded in the clinical picture, which emphasizes the need for prevention of this disease.In the period from 1.02.2018 to 31.01.2020 at the Clinic for Infectious diseases were treated 1060 patients with diarrheal disease, of which 502 children (47.36%). Rotavirus etiology was confirmed in 23.30% of the children. According to the protocols, laboratory and biochemical investigations were done to all 117 children, with tracking parameters and their dynamics of admission and discharge from the hospital. Most of the children, 84 (82.0 6%) are from urban areas, with a more confirmed epidemiological survey of 59 (42.00%). The average age of the children was 8 months, with a small percentage of children on maternal food (breastfed 25, i.e. 21.37%), with high febrile admission in 99% of children with an average temperature of 38.5oC and an average febrile duration of 4 days, with an average of 7 (+ 2.49) of stools and 5 (+ 2.12) of vomiting. There was a significant difference in hematocrit, leukocyte, electrolyte, glycaemia, and CRP values on admission and discharge. There was predominant isonatremic dehydration, and the compensatory mechanisms followed by the values of the electrolytes ABS, Ph, BE showed a tendency to maintain within the physiological limits. The clinical picture of extraintestinal manifestations included bronchitis, mesenteric lymphadenitis, upper respiratory infections and rash.Rotavirus infection is a serious health and economic problem in our country, so it needs continuous prevention and monitoring in order to reduce the incidence, and thus the need for hospitalization and cure of rotavirus disease.

Lessons Learned from Long-Term Assessment of Rotavirus Vaccination in a High-Income Country: The Case of the Rotavirus Vaccine Belgium Impact Study (RotaBIS)

INTRODUCTION

The rotavirus (RV) vaccine Belgium Impact Study (RotaBIS) evaluated the vaccine effect on RV-related hospital care in children up to 5 years old over a period of 13 years. Different forces were identified that influence the reduction in hospital care. Our analysis aims to report on the current RotaBIS dataset and explore through model simulation whether, how, and when the results could have been improved.

METHODS

As performed in previous assessments, this analysis evaluated RV-related events per year, per age group, RV nosocomial infections, hospitalization duration, and herd effect. It subsequently identified results that were surprising or unexpected. To know whether those data could have been improved through specific interventions, we developed a model with the forces acting on the disease transmission and the vaccine effect on RV-related hospital care. Scenario analysis of the forces should explain the current findings and identify ways to optimize the results.

RESULTS

The RotaBIS data show that annual RV-related hospital cases (n = 1345 pre-vaccination) dropped by 70% (95% confidence interval [CI] 66-74%) by year 5 (n = 395) after vaccine introduction, and by 84% (95% CI 79-89%) by year 10 (n = 217). The herd effect during the first year was limited to 14% extra gain. During the last 5 years, small disease increases were seen biennially. The simulation model indicates that higher vaccine coverage of the major transmitters during the peak season of the first year of vaccination could have reduced RV-related hospital care by nearly 90% at 5 and 10 years after vaccine introduction owing to a higher herd effect. The smaller peaks observed in recent years would have been dramatically reduced.

CONCLUSION

The current RotaBIS data show a maintained reduction, around 76%, in RV hospitalization cases. Simulations show that these results could have been improved to an important extent with a more optimal initiation of the vaccination program.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01563146 and NCT01563159.

Adapting Syndromic Surveillance Baselines After Public Health Interventions

BACKGROUND

Public health surveillance requires historical baselines to identify unusual activity. However, these baselines require adjustment after public health interventions. We describe an example of such an adjustment after the introduction of rotavirus vaccine in England in July 2013.

METHODS

We retrospectively measured the magnitude of differences between baselines and observed counts (residuals) before and after the introduction of a public health intervention, the introduction of a rotavirus vaccine in July 2013. We considered gastroenteritis, diarrhea, and vomiting to be indicators for national syndromic surveillance, including telephone calls to a telehealth system, emergency department visits, and unscheduled consultations with general practitioners. The start of the preintervention period varied depending on the availability of surveillance data: June 2005 for telehealth, November 2009 for emergency departments, and July 2010 for general practitioner data. The postintervention period was July 2013 to the second quarter of 2016. We then determined whether baselines incorporating a step-change reduction or a change in seasonality resulted in more accurate models of activity.

RESULTS

Residuals in the unadjusted baseline models increased by 42%-198% from preintervention to postintervention. Increases in residuals for vomiting indicators were 19%-44% higher than for diarrhea. Both step-change and seasonality adjustments improved the surveillance models; we found the greatest reduction in residuals in seasonally adjusted models (4%-75%).

CONCLUSION

Our results demonstrated the importance of adjusting surveillance baselines after public health interventions, particularly accounting for changes in seasonality. Adjusted baselines produced more representative expected values than did unadjusted baselines, resulting in fewer false alarms and a greater likelihood of detecting public health threats.

The Use of Test-negative Controls to Monitor Vaccine Effectiveness: A Systematic Review of Methodology

BACKGROUND

The test-negative design is an increasingly popular approach for estimating vaccine effectiveness (VE) due to its efficiency. This review aims to examine published test-negative design studies of VE and to explore similarities and differences in methodological choices for different diseases and vaccines.

METHODS

We conducted a systematic search on PubMed, Web of Science, and Medline, for studies reporting the effectiveness of any vaccines using a test-negative design. We screened titles and abstracts and reviewed full texts to identify relevant articles. We created a standardized form for each included article to extract information on the pathogen of interest, vaccine(s) being evaluated, study setting, clinical case definition, choices of cases and controls, and statistical approaches used to estimate VE.

RESULTS

We identified a total of 348 articles, including studies on VE against influenza virus (n = 253), rotavirus (n = 48), pneumococcus (n = 24), and nine other pathogens. Clinical case definitions used to enroll patients were similar by pathogens of interest but the sets of symptoms that defined them varied substantially. Controls could be those testing negative for the pathogen of interest, those testing positive for nonvaccine type of the pathogen of interest, or a subset of those testing positive for alternative pathogens. Most studies controlled for age, calendar time, and comorbidities.

CONCLUSIONS

Our review highlights similarities and differences in the application of the test-negative design that deserve further examination. If vaccination reduces disease severity in breakthrough infections, particular care must be taken in interpreting vaccine effectiveness estimates from test-negative design studies.

Missed Opportunities for Rotavirus Vaccination

BACKGROUND

Rotavirus remains an important cause of gastroenteritis and has been associated with the hospitalization of 34 to 53 per 10 000 children <5 years of age in the United States annually from 2008 to 2012. Rotavirus vaccines are underused compared with other routine vaccines. We describe rotavirus vaccine coverage and missed opportunities for rotavirus vaccination.

METHODS

The National Immunization Survey is a random-digit-dial, population-based survey including US children 19 to 35 months of age. Children fully vaccinated for rotavirus were those who received 3 doses of the pentavalent rotavirus vaccine, 2 doses of the monovalent rotavirus vaccine, or ≥3 doses of either vaccine type. Doses of the diphtheria-tetanus-acellular pertussis vaccine received from 6 weeks through 8 months and 0 days of age when the rotavirus vaccine was not received were considered missed opportunities for rotavirus vaccination according to Advisory Committee on Immunization Practices (ACIP) guidelines, and doses of the diphtheria-tetanus-acellular pertussis vaccine or measles-mumps-rubella vaccine from 6 weeks through 24 months and 0 days of age were considered missed opportunities according to World Health Organization recommendations.

RESULTS

Of the 14 571 children included in the 2014 National Immunization Survey, 71% were fully vaccinated for rotavirus. Lower socioeconomic status increased the likelihood of being unvaccinated for rotavirus. Among the 14% of children who received no doses of the rotavirus vaccine, 72% had ≥1 ACIP-defined missed opportunities, and 83% had ≥1 World Health Organization-defined missed opportunities. Higher socioeconomic status increased the likelihood of having missed opportunities. Complete rotavirus vaccine coverage could be improved to 81% if all missed opportunities within the ACIP-recommended schedule were addressed.

CONCLUSIONS

Addressing missed opportunities for rotavirus vaccination is essential to achieving the 80% rotavirus vaccine coverage target outlined by Healthy People 2020.

Rotavirus gastroenteritis hospitalization rates and correlation with rotavirus vaccination coverage in Sicily

Background and aim of the works:Rotavirus (RV) is considered the main cause of gastroenteritis in children from 0 to 59 months and vaccination represents the only strategy to prevent hospitalizations due to RV. In 2013 Sicilian Region introduced universal RV vaccination for all newborns. The present study aims to estimate the reduction rotavirus gastroenteritis (RVGE) hospitalization rates among Sicilian children and their relations with vaccination coverages of the nine Sicilian Local Health Units (LHUs). Methods: Were analyzed hospital discharge records including a diagnosis of RVGE occurred from January 2009 to December 2017 in hospitalized children aged 0 to 59 months, residents in Sicily. Were reported data on complete RV vaccination cycles among Sicilian children under 12 months of age (vaccination coverage). Results: A 49.2% overall reduction of RVGE hospitalization rates was reported after RV vaccination introduction. A more considerable reduction of hospitalization rates was observed among children aged 0 to 11 months (-61.4%), followed by children aged 12-23 months (-51.2%) and 24-35 months (-48.8%). In all the nine Sicilian Local Health Units (LHUs), a reduction of RVGE hospitalization rates was observed after RV vaccine implementation. Conclusions: This study demonstrated the significant impact of RV vaccination on RVGE hospitalization rates in Sicily, especially among children aged 0 to 23 months. The reduction in RVGE hospitalization rates observed in the Sicilian LHUs after universal vaccination program implementation, were generally higher or consistent with average vaccination coverage reported from 2013 to 2017. (www.actabiomedica.it)

Rotavirus Vaccines: Effectiveness, Safety, and Future Directions

Rotavirus is the leading cause of diarrheal death among children < 5 years old worldwide, estimated to have caused ~ 215,000 deaths in 2013. Prior to rotavirus vaccine implementation, > 65% of children had at least one rotavirus diarrhea illness by 5 years of age and rotavirus accounted for > 40% of all-cause diarrhea hospitalizations globally. Two live, oral rotavirus vaccines have been implemented nationally in > 100 countries since 2006 and their use has substantially reduced the burden of severe diarrheal illness in all settings. Vaccine efficacy and effectiveness estimates suggest there is a gradient in vaccine performance between low child-mortality countries (> 90%) and medium and high child-mortality countries (57-75%). Additionally, an increased risk of intussusception (~ 1-6 per 100,000 vaccinated infants) following vaccination has been documented in some countries, but this is outweighed by the large benefits of vaccination. Two additional live, oral rotavirus vaccines were recently licensed and these have improved on some programmatic limitations of earlier vaccines, such as heat stability, cost, and cold-chain footprint. Non-replicating rotavirus vaccines that are parenterally administered are in clinical testing, and these have the potential to reduce the performance differential and safety concerns associated with live oral rotavirus vaccines.

A benefit-risk analysis of rotavirus vaccination, France, 2015

Two vaccines available for protection against rotavirus gastroenteritis (RVGE), Rotarix and RotaTeq, have contributed to a large decrease in the incidence of paediatric diarrhoea in countries where they have been used. However, they have also led to a small increase in the risk of intussusception. Methods: We compare the number of prevented hospitalisations for RVGE to the number of vaccine-induced hospitalised intussusceptions in France. Results: With 9.5% coverage (French 2015 estimation), vaccination was estimated to prevent, annually, a median of 1,074 hospitalisations (2.5th and 97.5th percentiles (2.5th–97.5th): 810–1,378) and 1.4 deaths (2.5th–97.5th: 1.2–1.6) from RVGE. It was also estimated to cause, annually, 5.0 hospitalisations (2.5th–97.5th: 3.2–7.7) and 0.005 deaths (2.5th–97.5th: 0.001–0.015) from intussusception. The benefit–risk ratio is therefore 214 (2.5th–97.5th: 128–362) for hospitalisations and 273 (2.5th–97.5th: 89–1,228) for deaths. Under a hypothetical 92% coverage, rotavirus vaccination with Rotarix would avoid 10,459 (2.5th–97.5th: 7,702–13,498) hospitalisations for RVGE and induce 47.0 (2.5th–97.5th: 25.1–81.4) hospitalisations for intussusception annually, thereby preventing 13.7 (2.5th–97.5th: 11.1–15.2) deaths and inducing 0.05 (2.5th–97.5th: 0.01–0.15) deaths. Conclusion: The benefit–risk ratio in France is similar to that of other European countries.

Effectiveness of Rotavirus Vaccination: A Systematic Review of the First Decade of Global Postlicensure Data, 2006-2016

Two rotavirus vaccines, Rotarix (RV1) and RotaTeq (RV5), were licensed for global use in 2006. A systematic review of 48 peer- reviewed articles with postlicensure data from 24 countries showed a median RV1 vaccine effectiveness (VE) of 84%, 75%, and 57% in countries with low, medium, and high child mortality, respectively, and RV5 VE of 90% and 45% in countries with low and high child mortality, respectively. A partial vaccine series provided considerable protection, but not to the same level as a full series. VE tended to decline in the second year of life, particularly in medium- and high-mortality settings, and tended to be greater against more severe rotavirus disease. Postlicensure data from countries across geographic regions and with different child mortality levels demonstrate that under routine use, both RV1 and RV5 are effective against rotavirus disease, supporting the World Health Organization recommendation that all countries introduce rotavirus vaccine into their national immunization program.

Sustained impact of rotavirus vaccine on rotavirus hospitalisations in Lusaka, Zambia, 2009-2016

BACKGROUND

Monovalent rotavirus vaccine (RV1) was introduced in Lusaka in February 2012 and rolled out countrywide in November 2013 in the routine Expanded Programme on Immunisation and administered at 6 and 10 weeks with no catch up dose. Reported here is the monitoring of rotavirus acute gastroenteritis hospitalisations at the University Teaching Hospital, Lusaka, Zambia as part of efforts to document the impact of rotavirus vaccine.

METHODS

Children <5 years hospitalised for acute gastroenteritis (AGE) from January 2009 to December 2016 were recruited into the rotavirus disease burden active surveillance and had their stools tested for rotavirus by enzyme immunoassay. We compared rotavirus-associated AGE hospitalisations of the pre-vaccine era (2009-2011) with the post-rotavirus vaccine introduction period (2013-2016).

RESULTS

With the increase in RV1 coverage in Lusaka, rotavirus AGE declined significantly from 40% of diarrhoea hospitalisation in the pre-vaccine era to 29% of diarrhoea hospitalisation in the post-vaccine era (p < 0.001) in children <5 years. After a decreasing trend in rotavirus positivity from 2013 to 2015, positivity increased to 37% in 2016. However, the post-vaccine years (2012-2016) saw substantial decline in the number tested (median decline: 34% (range: 20-43%)) and the number of positive results (median decline: 52% (range: 30-65%).

CONCLUSION

A sustained and significant decline in rotavirus AGE hospitalisations was observed in children <5 years since the introduction of RV1 in Lusaka, Zambia. Despite an increase in rotavirus positivity in 2016, the total number of children enrolled and the number of rotavirus positive children remained below baseline. The reason for the increase in rotavirus positivity in 2016 is unknown but could be due to an accumulation of susceptible children and the shifting of disease to children of older age groups. This finding underscores the need for continued monitoring of rotavirus vaccine impact.

Rotavirus vaccine impact and socioeconomic deprivation: an interrupted time-series analysis of gastrointestinal disease outcomes across primary and secondary care in the UK

BACKGROUND

Rotavirus causes severe gastroenteritis in infants and young children worldwide. The UK introduced the monovalent rotavirus vaccine (Rotarix®) in July 2013. Vaccination is free of charge to parents, with two doses delivered at 8 and 12 weeks of age. We evaluated vaccine impact across a health system in relation to socioeconomic deprivation.

METHODS

We used interrupted time-series analyses to assess changes in monthly health-care attendances in Merseyside, UK, for all ages, from July 2013 to June 2016, compared to predicted counterfactual attendances without vaccination spanning 3-11 years pre-vaccine. Outcome measures included laboratory-confirmed rotavirus gastroenteritis (RVGE) hospitalisations, acute gastroenteritis (AGE) hospitalisations, emergency department (ED) attendances for gastrointestinal conditions and consultations for infectious gastroenteritis at community walk-in centres (WIC) and general practices (GP). All analyses were stratified by age. Hospitalisations were additionally stratified by vaccine uptake and small-area-level socioeconomic deprivation.

RESULTS

The uptake of the first and second doses of rotavirus vaccine was 91.4% (29,108/31,836) and 86.7% (27,594/31,836), respectively. Among children aged < 5 years, the incidence of gastrointestinal disease decreased across all outcomes post-vaccine introduction: 80% (95% confidence interval [CI] 70-87%; p < 0.001) for RVGE hospitalisation, 44% (95% CI 35-53%; p < 0.001) for AGE hospitalisations, 23% (95% CI 11-33%; p < 0.001) for ED, 32% (95% CI 7-50%; p = 0.02) for WIC and 13% (95% CI -3-26%; p = 0.10) for GP. The impact was greatest during the rotavirus season and for vaccine-eligible age groups. In adults aged 65+ years, AGE hospitalisations fell by 25% (95% CI 19-30%; p < 0.001). The pre-vaccine risk of AGE hospitalisation was highest in the most socioeconomically deprived communities (adjusted incident rate ratio 1.57; 95% CI 1.51-1.64; p < 0.001), as was the risk for non-vaccination (adjusted risk ratio 1.54; 95% CI 1.34-1.75; p < 0.001). The rate of AGE hospitalisations averted per 1,000 first doses of vaccine was higher among infants in the most deprived communities compared to the least deprived in 2014/15 (28; 95% CI 25-31 vs. 15; 95% CI 12-17) and in 2015/16 (26; 95% CI 23-30 vs. 13; 95% CI 11-16).

CONCLUSIONS

Following the introduction of rotavirus vaccination, incidence of gastrointestinal disease reduced across the health-care system. Vaccine impact was greatest among the most deprived populations, despite lower vaccine uptake. Prioritising vaccine uptake in socioeconomically deprived communities should give the greatest health benefit in terms of population disease burden.

Sustained High Effectiveness of RotaTeq on Hospitalizations Attributable to Rotavirus-Associated Gastroenteritis During 4 Years in Finland

KEY POINTS

The effectiveness of pentavalent rotavirus vaccine against rotavirus-associated hospitalization was more than 90% 4 years after introduction into the national immunization program in Finland. A major impact on hospitalization for all-cause gastroenteritis was observed also.

BACKGROUND

Rotavirus vaccination with exclusive use of RotaTeq was added to the National Immunization Programme (NIP) of Finland in September 2009. The objective of our study was to estimate the effectiveness and impact of RotaTeq after 4 years of follow-up.

METHODS

Between 2009 and 2013, we conducted a prospective surveillance study of children aged <16 years with acute gastroenteritis (AGE) and admitted in 2 hospitals in Finland. Rotavirus and other gastroenteritis viruses were detected in stool samples by reverse-transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assays. The effectiveness of RotaTeq was investigated by using a case-control design; wild-type rotavirus-positive children were classified as "cases" and rotavirus-negative children as "controls." Hospital discharge records were used to estimate the impact of RotaTeq on rotavirus-associated AGE (RV-AGE) and all-cause AGE (AC-AGE) hospitalizations of age-eligible children in the NIP by comparing the prevaccination (2001-2006) and post-NIP seasons (2009-2013).

RESULTS

The crude estimate of the effectiveness of RotaTeq to prevent RV-AGE hospitalization in NIP age-eligible children was 94.4% (95% confidence interval, 79.8%-98.4%). No change in prevalent wild-type rotavirus genotypes was observed. Vaccine-derived rotaviruses were detected in 8% of the children with RV-AGE, with a probable causal association in 2 children. Hospital discharge records revealed that RV-AGE and AC-AGE hospitalizations in children aged <16 years decreased in the two post-NIP seasons by 79% and 58%, respectively, compared to those in the prevaccination seasons.

CONCLUSIONS

Over 4 years of follow-up, high rotavirus vaccine coverage in the NIP (>95%) has led to a major reduction in RV-AGE and AC-AGE hospitalizations without a resurgence of rotavirus activity. However, rotavirus continues to circulate in older unvaccinated children.

Effectiveness of rotavirus vaccines against hospitalisations in Japan

BACKGROUND

In Japan, rotavirus hospitalisation occurs at a rate from 2.8 to 13.7 per 1000 child-years among children age less than 5 years, and it imposes a substantial burden to the healthcare system in the country. While both monovalent (RV1) and pentavalent (RV5) rotavirus vaccines are licensed in Japan, neither has been incorporated in the national infant immunization programme. In this study, we estimated vaccine effectiveness (VE) in Japan.

METHODS

This study was conducted in Yuri-Kumiai General Hospital located in a city in the north-western part of Japan. Age-eligible children for rotavirus vaccination were enrolled if they were hospitalized for rotavirus gastroenteritis between September 2013 and August 2016. Rotavirus gastroenteritis was defined by the detection of rotavirus antigen by immunochromatography. "Vaccinated" was defined as infant inoculated with at least one dose of either RV1 or RV5. A conditional logistic regression analysis was performed by modelling the year of birth, year of admission, residence of the children and vaccination status, and by matching the age of cases with that of test-negative controls. The adjusted odds ratio of the vaccinated over unvaccinated was then used to calculate VE in the formula of (1 - adjusted odds ratio) × 100.

RESULTS

Out of the 244 patients enrolled, rotavirus antigen was detected in 55 (22.5%) of whom 10 (18.2%) were vaccinated, whereas 94 (49.7%) of 189 test-negative controls were vaccinated. During the study period, the vaccine uptake rate in the controls increased from 36.2% to 61.8%. On the other hand, the vaccination coverage over the three years was 64.2% in Yuri-Honjo city (three quarters of the catchment), and 91.4% in Nikaho city (one quarter of the catchment). The VE was calculated to be 70.4% (95% confidence interval: 36.0-86.4%, P = 0.002). The point estimate of the VE was lower but its 95% confidence interval overlaps those of the efficacies obtained from clinical trials in Japan.

CONCLUSION

The rotavirus vaccine was effective in the real-world setting in Japan as in the clinical trials, and the introduction of rotavirus vaccine in the national infant immunization schedule will substantially reduce the number of rotavirus gastroenteritis hospitalisation in Japan.

Efficacy, safety and effectiveness of licensed rotavirus vaccines: a systematic review and meta-analysis for Latin America and the Caribbean

BACKGROUND

RotaTeq™ (RV5; Merck & Co. Inc., USA) and Rotarix™ (RV1, GlaxoSmithKline, Belgium) vaccines, developed to prevent rotavirus diarrhea in children under five years old, were both introduced into national immunization programs in 2006. As many countries in Latin America and the Caribbean have included either RV5 or RV1 in their routine childhood vaccination programs, we conducted a systematic review and meta-analysis to analyze efficacy, safety and effectiveness data from the region.

METHODS

We conducted a systematic search in PubMed, EMBASE, Scielo, Lilacs and the Cochrane Central Register, for controlled efficacy, safety and effectiveness studies published between January 2000 until December 2011, on RV5 and RV1 across Latin America (where both vaccines are available since 2006). The primary outcome measures were: rotavirus-related gastroenteritis of any severity; rotavirus emergency department visits and hospitalization; and severe adverse events.

RESULTS

The results of the meta-analysis for efficacy show that RV1 reduced the risk of any-severity rotavirus-related gastroenteritis by 65% (relative risk (RR) 0.35, 95% confidence interval (CI) 0.25; 0.50), and of severe gastroenteritis by 82% (RR 0.18, 95%CI 0.12; 0.26) versus placebo. In trials, both vaccines significantly reduced the risk of hospitalization and emergency visits by 85% (RR 0.15, 95%CI 0.09; 0.25) for RV1 and by 90% (RR 0.099, 95%CI 0.012; 0.77) for RV5. Vaccination with RV5 or RV1 did not increase the risk of death, intussusception, or other severe adverse events which were previously associated with the first licensed rotavirus vaccine. Real-world effectiveness studies showed that both vaccines reduced rotavirus hospitalization in the region by around 45-50% for RV5 (for 1 to 3 doses, respectively), and, by around 50-80% for RV1 (for 1 to 2 doses, respectively). For RV1, effectiveness against hospitalization was highest (around 80-96%) for children vaccinated before 12 months of age, compared with 5-60% effectiveness in older children. Both vaccines were most effective in preventing more severe gastroenteritis (70% for RV5 and 80-90% for RV1) and severe gastroenteritis (50% for RV5 and 70-80% for RV1).

CONCLUSION

This systematic literature review confirms rotavirus vaccination has been proven effective and well tolerated in protecting children in Latin America and the Caribbean.

Evaluating the first introduction of rotavirus vaccine in Thailand: Moving from evidence to policy

BACKGROUND

We assessed the effectiveness and possible impact of introducing rotavirus vaccine into the routine immunization program.

METHODS

Two provinces were selected for an observational study, one where vaccine was introduced and another where vaccine was not available. In these areas, two sub-studies were linked. The prospective cohort study enrolled children 2month old and followed them to the age of 18months to detect all diarrhea episodes. The hospital surveillance study enrolled all children up to age 5 hospitalized with diarrhea whose fecal samples were tested for rotavirus. Rates of rotavirus hospitalizations in older children who had not been vaccinated in both settings provided data to determine whether immunization had an indirect herd effect. The key endpoints for the study were both vaccine effectiveness (VE) based upon hospitalized rotavirus diarrhea and herd protection.

FINDINGS

From the cohort study, the overall VE for hospitalized rotavirus diarrhea was 88% (95%CI 76-94). Data from hospital surveillance indicated that for 2 consecutive years, the seasonal peak of rotavirus admissions was no longer present in the vaccinated area. Herd protection was observed among older children born before the rotavirus vaccine program was introduced, who experienced a 40-69% reduction in admission for rotavirus.

CONCLUSIONS

Rotavirus vaccine was highly effective in preventing diarrheal hospitalizations and in conferring herd protection among older children who had not been vaccinated.

Real-World Effectiveness of Pentavalent Rotavirus Vaccine Among Bedouin and Jewish Children in Southern Israel

BACKGROUND

Pentavalent rotavirus vaccine (RV5) was introduced into the Israeli National Immunization Program in January 2011. We determined RV5 vaccine effectiveness (VE) in southern Israel, a region characterized by 2 distinct populations: Bedouins living in a low- to middle-income, semirural setting, and Jews living in a high-income, urban setting.

METHODS

We enrolled vaccine-eligible children who visited the emergency department (ED) or were hospitalized due to acute gastroenteritis (AGE) during the first 3 rotavirus seasons after RV5 vaccine introduction (2011-2013). Fecal specimens were tested for rotavirus by enzyme immunoassay and genotyped. Vaccination among laboratory-confirmed rotavirus cases was compared with rotavirus-negative AGE controls. Regression models were used to calculate VE estimates by age, clinical setting, and ethnicity.

RESULTS

Of 515 enrolled patients, 359 (70%) were Bedouin. Overall, 185 (36%) patients were rotavirus positive; 79 of 119 (66%) were G1P[8] genotype. The adjusted VE for a full 3-dose course of RV5 against ED visit or hospitalization was 63% (95% confidence interval [CI], 38%-78%). RV5 provided G1P[8] genotype-specific effectiveness of 78% (95% CI, 58%-88%). By age, RV5 VE was 64% (95% CI, 21%-84%) and 71% (95% CI, 39%-86%) among children aged 6-11 months and 12-23 months, respectively. By clinical setting, RV5 VE was 59% (95% CI, 23%-78%) against hospitalization, and 67% (95% CI, 11%-88%) against ED visit. The adjusted VE of a full RV5 course among Bedouin children was 62% (95% CI, 29%-79%).

CONCLUSIONS

RV5 significantly protected against rotavirus-associated ED visits and hospitalizations in a diverse population of vaccine-eligible children living in southern Israel.

Decrease of Rotavirus Gastroenteritis to a Low Level Without Resurgence for Five Years After Universal RotaTeq Vaccination in Finland

BACKGROUND

Universal rotavirus (RV) vaccination with RotaTeq was introduced into National Immunization Programme (NIP) of Finland in September 2009. We have previously reported the reduction of RV gastroenteritis (GE) cases in the first 2 years after RV vaccination in NIP in Finland.

METHODS

In Tampere University Hospital, a 2-year survey of acute GE (AGE) in children was conducted before NIP in the years 2006 to 2008. This was followed by a similar prospective survey in years 2009 to 2011 and now extended to years 2012 to 2014. Stool samples from children examined in the hospital for AGE were analyzed by real-time polymerase chain reaction assays for RV and norovirus, and positive samples were typed by sequencing.

RESULTS

The proportion of RVGE of all AGE cases decreased from 52% (421 of 809 cases) in pre-NIP years to 26% (86 of 330 cases) in post-NIP years 2009 to 2011 falling to 12% (40 of 347 cases) in 2012 and 2014. The hospitalizations for RVGE were reduced by 90% and the outpatient clinic visits also by 90% in 2012 to 2014, compared with pre-NIP year; all AGE cases were reduced by 59%. Norovirus was a major causative agent of AGE in the post-NIP period, accounting for 34% of the cases in 2009 to 2011 and 29% in 2012 to 2014.

CONCLUSIONS

RV vaccination in NIP has led to a major reduction of RVGE cases seen in hospital with no resurgence in 5 years after NIP. A high coverage of RV vaccination will maintain RV activity at a low level but not eliminate wild-type RV circulation.

Effectiveness of rotavirus vaccine in preventing severe gastroenteritis in young children according to socioeconomic status

In 2011, the monovalent rotavirus vaccine was introduced into a universal immunization program in Quebec (Canada). This retrospective cohort study assessed vaccine effectiveness (VE) in preventing acute gastroenteritis (AGE) and rotavirus gastroenteritis (RVGE) hospitalizations among children <3 y living in the Quebec Eastern Townships region according to socioeconomic status (SES). Data were gathered from a tertiary hospital database paired with a regional immunization registry. Three cohorts of children were followed: (1) vaccinated children born in post-universal vaccination period (2011-2013, n = 5,033), (2) unvaccinated children born in post-universal vaccination period (n = 1,239), and (3) unvaccinated children born in pre-universal vaccination period (2008-2010, n = 6,436). In each cohort, AGE and RVGE hospitalizations were identified during equivalent follow-up periods to calculate VE globally and according to neighborhood-level SES. Using multivariable logistic regression, adjusted odds ratios (OR) were computed to obtain VE (1-OR). Adjusted VE of 2 doses was 62% (95% confidence interval [CI]: 37%-77%) and 94% (95%CI: 52%-99%) in preventing AGE and RVGE hospitalization, respectively. Stratified analyses according to SES showed that children living in neighborhoods with higher rates of low-income families had significantly lower VE against AGE hospitalizations compared to neighborhoods with lower rates of low-income families (30% vs. 78%, p = 0.027). Our results suggest that the rotavirus vaccine is highly effective in preventing severe gastroenteritis in young children, particularly among the most well-off. SES seems to influence rotavirus VE, even in a high-income country like Canada. Further studies are needed to determine factors related to lower rotavirus VE among socioeconomically disadvantaged groups.

A Systematic Review of the Effect of Rotavirus Vaccination on Diarrhea Outcomes Among Children Younger Than 5 Years

BACKGROUND

Rotavirus is the leading cause of vaccine-preventable diarrhea among children under 5 globally. Rotavirus vaccination has been shown to prevent severe rotavirus infections with varying efficacy and effectiveness by region.

METHODS

We sought to generate updated region-specific estimates of rotavirus vaccine efficacy and effectiveness. We systematically reviewed published vaccine efficacy and effectiveness studies to assess the region-specific effect of rotavirus vaccination on select diarrheal morbidity and mortality outcomes in children under 5 years of age. We employed meta-analytic methods to generate pooled effect sizes by Millennium Development Goal region.

RESULTS

Rotavirus vaccination was both efficacious and effective in preventing rotavirus diarrhea, severe rotavirus diarrhea and rotavirus hospitalizations among children under 5 across all regions represented by the 48 included studies. Efficacy against severe rotavirus diarrhea ranged from 90.6% [95% confidence interval (CI): 82.3-95.0] in the developed region to 88.4% (95% CI: 67.1-95.9) in Eastern/Southeastern Asia, 79.6% (95% CI: 71.3-85.5) in Latin America and the Caribbean, 50.0% (95% CI: 34.4-61.9) in Southern Asia and 46.1% (95% CI: 29.1-59.1) in sub-Saharan Africa. Region-specific effectiveness followed a similar pattern. There was also evidence of vaccine efficacy against severe diarrhea and diarrheal hospitalizations.

CONCLUSION

Our findings confirm the protective efficacy and effectiveness of rotavirus vaccination against rotavirus diarrheal outcomes among children under 5 globally.

Burden of Rotavirus Disease in Norway: Using National Registries for Public Health Research

BACKGROUND

Norway introduced routine rotavirus immunization for all children born on or after September 1, 2014. We estimated the healthcare burden of all-cause gastroenteritis and rotavirus disease in children <5 years old to establish the prevaccine baseline and support the ongoing immunization program.

METHODS

We examined national registry data on gastroenteritis-associated primary care consultations and hospitalizations for 2009-2013 and data on all deaths in children <5 years old reported during 2000-2013. We also established rotavirus hospital surveillance from February 2014 through January 2015.

RESULTS

Before vaccine introduction, 114.5 cases per 1000 children <5 years old were treated in primary care and 11.8 children per 1000 were hospitalized with gastroenteritis annually. During hospital surveillance, rotavirus was detected in 65% (95% confidence interval: 60-70) of inpatient gastroenteritis cases. We estimated that 4.0 inpatient and 2.3 outpatient cases per 1000 children were seen in hospital with rotavirus disease annually, suggesting that 1 in 32 children was hospitalized by age 5. Additional 30.6 rotavirus cases per 1000 children consulted primary care annually or 1 in every 7 children by the age of 5 years. Rotavirus-associated mortality was estimated at 0.17 deaths per 100,000 children <5 years old, corresponding to 1 death every second year.

CONCLUSIONS

Rotavirus remains the primary cause of severe gastroenteritis in children in Norway. The unique population-based registers, in combination with an established rotavirus surveillance platform, provide a well-suited setting to evaluate the impact of rotavirus vaccination.

Evaluation of the Intussusception Risk after Pentavalent Rotavirus Vaccination in Finnish Infants

BACKGROUND

An association between rotavirus immunisation and intussusception (IS) has been suggested with present rotavirus vaccines in post-licensure studies. In Finland, rotavirus vaccination programme was implemented in September 2009 using a 2, 3, and 5 months schedule with the pentavalent rotavirus vaccine. By the end of 2013, it is estimated that 719 000 rotavirus vaccine doses have been given in the national programme of which 240 000 were first doses. Nationwide register allows us to evaluate the association between rotavirus vaccination and IS.

METHODS AND MATERIALS

Cases of IS diagnosed during 1999-2013 were identified from National Hospital Discharge Register. All cases under 250 days of age diagnosed during 2009-2013 were confirmed by reviewing medical charts. Self-controlled case-series method was used to assess the risk of IS during 1-21 days compared to 22-42 days post vaccination.

FINDINGS

In register data the relative incidence of IS at 2 months of age between the post and pre vaccination era was 9.1 (95%CI 2.0-84.3). We identified 22 verified cases with date of admission less than 43 days after any of the three rotavirus vaccine doses. The incidence of IS in the risk period after the 1st dose relative to the control period was 2.0 (95% CI 0.5-8.4; p = 0.34.) Number of excess IS cases per 100 000 first vaccine doses was therefore estimated to be 1.04 (95% CI 0.0-2.5), i.e. one additional IS case per 96 000 first doses of rotavirus vaccine (95% CI 54 600 to ∞). There was no risk detected after 2nd and 3rd doses.

CONCLUSION

The finding is in line with the recent published estimates. The benefits of rotavirus immunisation programme outweigh possible small risks of intussusception.

Medium- to Long-Term Impact of Rotavirus Vaccination on Hospital Care in Belgium: A 7-Year Follow-Up of the Rotavirus Belgium Impact Study (RotaBIS)

Introduction

Rotavirus (RV) vaccination was introduced in Belgium in 2006. With the high uptake it had (>85%), a sharp decline in hospitalizations was observed during the first years after vaccine introduction. The objective of this study was to investigate whether this decline was maintained and to simulate projections.

Methods

The Rotavirus Belgium Impact Study allowed an analysis of the RV vaccine impact amongst children in 11 hospitals in Belgium over a 9-year period (2005–2013) with 2 years pre- and 7 years post-vaccine introduction. Results were compared by year and by subsequent birth cohort aging up to 5 years. The two different analysis methods helped dismantling the different (direct and indirect) effects of vaccine protection to simulate future hospitalization trends.

Results

During the whole observation period, 40,552 RV detection tests were performed of which 5832 were positive (14.4%). After RV vaccine introduction, a significant reduction in number of tests performed (−38%) was combined with a dramatic drop in numbers of positive tests (−76.6%). The decreases were spectacular during the first two years of vaccine introduction; after that period, the decrease flattened. Cross-sectional comparison with cohort data showed that the initial drop was heavily influenced by the herd effect of the vaccine. Cohort analysis demonstrated a low rate of residual disease over time, suggesting another infection source other than the child population.

Conclusion

The residual disease will be maintained in the community when a same vaccination strategy is continued over time, starting vaccination of children only at 6 weeks’ time.

Funding

GlaxoSmithKline Biologicals SA.

Trial registration

ClinicalTrials.gov identifier, NCT01563146.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-015-0099-1) contains supplementary material, which is available to authorized users.

Rapid Declines in Age Group-Specific Rotavirus Infection and Acute Gastroenteritis Among Vaccinated and Unvaccinated Individuals Within 1 Year of Rotavirus Vaccine Introduction in England and Wales

BACKGROUND

The oral infant rotavirus vaccine, Rotarix, was introduced in England and Wales in July 2013. We estimated the impact on laboratory-confirmed rotavirus infections and hospitalizations for all-cause acute gastroenteritis (AGE) during the first year after introduction.

METHODS

We extracted data on laboratory-confirmed rotavirus infections (July 2000 through June 2015) and all-cause AGE-associated hospitalizations (July 2007 through June 2014) for all age groups using national databases (LabBase2 and HES). We determined the ratio of the rate during the 2013-2014 rotavirus season to the rate during the prevaccination era.

RESULTS

In infants, there was a 77% decline (rate ratio [RR], 0.23; 95% confidence interval [CI], .16-.32) in laboratory-confirmed rotavirus infections and a 26% decline (RR, 0.74; 95% CI, .65-.84) in all-cause AGE-associated hospitalizations in 2013-2014, compared with the prevaccination era. Large reductions were also observed in older children, adults, and older adults. We estimated that 10 884 laboratory-confirmed infections and 50 427 all-cause AGE-associated hospital admissions were averted in 2013-2014. Similar reductions have been observed for laboratory-confirmed rotavirus infections during the 2014-2015 season.

CONCLUSIONS

The rapid declines in rotavirus infection and AGE in vaccinated and unvaccinated age groups within 1 year of introducing an infant rotavirus vaccination program are far greater than expected and than previously reported by other countries.

European Society for Paediatric Infectious Diseases consensus recommendations for rotavirus vaccination in Europe: update 2014

The first evidence-based recommendations for rotavirus (RV) vaccination in Europe were prepared at the time of licensure of 2 live oral RV vaccines (Rotarix, GlaxoSmithKline Biologicals, and RotaTeq, Sanofi Pasteur MSD) in 2006 and published in 2008. Since then several countries in Europe and more globally have adopted universal RV vaccination of all healthy infants as part of their national immunization programs (NIPs). The experience from these NIPs has produced a wealth of post-introduction effectiveness data that, together with the evidence from prelicensure efficacy trials presented in the 2008 Recommendations, support the case of RV vaccination in Europe. The prelicensure safety trials of Rotarix and RotaTeq, each in populations of more than 60,000 infants, did not reveal risk of intussusception (IS), but postvaccination surveillance in several countries, particularly Australia and Mexico, has established that the risk of IS for both vaccines after the first dose might be between 1:50,000 and 1:80,000. Although it may be argued that the risk is acceptable vis-à-vis the great benefits of RV vaccination, this argument alone may not suffice, and every effort should be made to reduce the risk of IS. Considerable evidence, including postvaccination surveillance data from Germany, suggests that the risk of IS can be reduced by early administration of the first dose of oral RV vaccine. The previous European Society for Paediatric Infectious Diseases/European Society for Paediatric Gastroenterology, Hepatology and Nutrition recommendations held that the first dose of oral RV vaccine should be given between 6 and 12 weeks of age; this recommendation is sustained but with an emphasis toward the lower range of the recommended age, that is, preferably between 6 and 8 weeks of age. At the time of the earlier recommendations, experience of RV vaccination in premature infants and other special target groups was limited. It is now recommended with greater confidence than before that prematurely born infants should be vaccinated according to their calendar age as recommended for full-term infants. It is now strongly recommended that all HIV-infected or HIV-exposed infants should be vaccinated with oral RV vaccine. Although specific information on many immunodeficiencies is lacking, infants with known severe combined immunodeficiency should not receive live RV vaccine.

Case control study of rotavirus vaccine effectiveness in Portugal during 6 years of private market use

BACKGROUND

Although recommended by the vaccine committee of the Portuguese Paediatric Society, rotavirus vaccines have not been included in the routine immunization schedule. They have been available privately since 2006 with estimated coverage reaching approximately 30%. However, unlike other European countries using the vaccine, sentinel surveillance has detected fluctuations but no clear trends in the rate of gastrointestinal disease presentations. In this study, we set out to establish the real world effectiveness of rotavirus immunization in this low vaccine coverage setting.

METHODS

We carried out a test-negative case control study on a population of children attending a regional pediatric hospital, between 2006 and 2012, with symptoms of acute gastroenteritis and producing a stool sample for routine rotavirus testing. We calculated exposure odds ratio (ratio of odds of antecedent vaccination among cases compared with controls) to derive vaccine effectiveness ([1 - adjusted odds ratio]/100) against both hospital attendance and admission.

RESULTS

Vaccine effectiveness against attendance with rotavirus acute gastroenteritis was 83.7% (95% confidence interval: 73.9-89.8) and against hospital admission was 96.1% (95% confidence interval: 83.8-99.1). No significant difference between the 2 available vaccines was detected.

CONCLUSION

Both rotavirus vaccines offer a high degree of individual protection in this population.

Whole genome detection of rotavirus mixed infections in human, porcine and bovine samples co-infected with various rotavirus strains collected from sub-Saharan Africa

Group A rotaviruses (RVA) are among the main global causes of severe diarrhea in children under the age of 5years. Strain diversity, mixed infections and untypeable RVA strains are frequently reported in Africa. We analysed rotavirus-positive human stool samples (n=13) obtained from hospitalised children under the age of 5years who presented with acute gastroenteritis at sentinel hospital sites in six African countries, as well as bovine and porcine stool samples (n=1 each), to gain insights into rotavirus diversity and evolution. Polyacrylamide gel electrophoresis (PAGE) analysis and genotyping with G-(VP7) and P-specific (VP4) typing primers suggested that 13 of the 15 samples contained more than 11 segments and/or mixed G/P genotypes. Full-length amplicons for each segment were generated using RVA-specific primers and sequenced using the Ion Torrent and/or Illumina MiSeq next-generation sequencing platforms. Sequencing detected at least one segment in each sample for which duplicate sequences, often having distinct genotypes, existed. This supported and extended the PAGE and RT-PCR genotyping findings that suggested these samples were collected from individuals that had mixed rotavirus infections. The study reports the first porcine (MRC-DPRU1567) and bovine (MRC-DPRU3010) mixed infections. We also report a unique genome segment 9 (VP7), whose G9 genotype belongs to lineage VI and clusters with porcine reference strains. Previously, African G9 strains have all been in lineage III. Furthermore, additional RVA segments isolated from humans have a clear evolutionary relationship with porcine, bovine and ovine rotavirus sequences, indicating relatively recent interspecies transmission and reassortment. Thus, multiple RVA strains from sub-Saharan Africa are infecting mammalian hosts with unpredictable variations in their gene segment combinations. Whole-genome sequence analyses of mixed RVA strains underscore the considerable diversity of rotavirus sequences and genome segment combinations that result from a complex evolutionary history involving multiple host species.

Effectiveness of rotavirus vaccines, licensed but not funded, against rotavirus hospitalizations in the Valencia Region, Spain

BACKGROUND

Although rotavirus vaccines have been licensed in Spain for over 8 years, they are not funded by its public health systems. The analysis of their effectiveness in the Valencia Region could better inform decisions about potential inclusion in the official immunization schedule. Our aim was to assess the effectiveness of Rotarix® (RV1) and RotaTeq® (RV5) against rotavirus hospitalizations.

METHODS

We conducted a retrospective cohort study using the region's health care databases, among resident children aged <3 years covered by the National Health System, during January 2007-June 2012. We compared two cohorts of vaccinated children: the first included children who received at least one dose of a rotavirus vaccine, and the second included children who were not vaccinated with rotavirus vaccines but received at least one dose of a pneumococcal vaccine, another licensed but non-funded vaccine. The main outcome was rotavirus hospitalization, either laboratory-confirmed (confirmed) or codified as rotavirus (probable). Rotavirus vaccine effectiveness (RVE) by vaccine brand was assessed using Cox proportional hazards models.

RESULTS

The study included 78,281 rotavirus and 96,643 pneumococcal vaccinees. Adjusted RVE against probable or confirmed rotavirus hospitalizations was 86% (95% CI: 78-91%) and 88% (95% CI: 81-92%) for a complete series of RV1 and RV5 respectively.

CONCLUSIONS

Both rotavirus vaccines were over 85% effective against rotavirus hospitalization among young children. The high effectiveness shown argues in favor of their inclusion in the official schedule. Additional information on rotavirus vaccine safety, duration of protection, and benefit-risk will also be needed to inform such deliberations.

Decline in rotavirus hospitalizations following the first three years of vaccination in Castile-La Mancha, Spain

Rotavirus is a major burden on the Spanish Healthcare System. Rotarix(®) and RotaTeq(®) were simultaneously commercialized in Spain by February, 2007. The objective is to analyze the incidence and seasonality of rotavirus hospitalizations (RH) in Castile-La Mancha (CLM), following the first 3 y of commercialization. A cross-sectional study of the hospital discharge registry's Minimum Basic Data Set (MBDS) in CLM between 2003 and 2009 was performed. We used the Poisson regression model to quantify the percentage of change in the rotavirus incidence rate (IR) for 2007-09 vs. 2003-05, adjusting for age, sex, and province. To analyze changes between epidemic seasons the chi-square test was used. The median IR in 2003-09 was 224.71 per 10(5) [interquartile range (IQR): 185.24-274.70], which represents 60% of hospital admissions due to infectious acute gastroenteritis. The median rate in 2007-09 decreased [incidence rate ratio (IRR): 0.86, 95% CI: 0.78-0.96], significantly in Toledo (IRR: 0.54, 95% CI: 0.39-0.75). An incipient decline at the beginning of the last cold season was observed, preceded by a significant decrease of 68% in the autumn season of 2009. Despite its limited coverage, the rotavirus vaccine may have contributed to decrease RH in CLM.

Quantifying Parameter and Structural Uncertainty of Dynamic Disease Transmission Models Using MCMC: An Application to Rotavirus Vaccination in England and Wales

BACKGROUND

Two vaccines (Rotarix and RotaTeq) are highly effective at preventing severe rotavirus disease. Rotavirus vaccination has been introduced in the United Kingdom and other countries partly based on modeling and cost-effectiveness results. However, most of these models fail to account for the uncertainty about several vaccine characteristics and the mechanism of vaccine action.

METHODS

A deterministic dynamic transmission model of rotavirus vaccination in the United Kingdom was developed. This improves on previous models by 1) allowing for 2 different mechanisms of action for Rotarix and RotaTeq, 2) using clinical trial data to understand these mechanisms, and 3) accounting for uncertainty by using Markov Chain Monte Carlo.

RESULTS

In the long run, Rotarix and RotaTeq are predicted to reduce the overall rotavirus incidence by 50% (39%-63%) and 44% (30%-62%), respectively but with an increase in incidence in primary school children and adults up to 25 y of age. The vaccines are estimated to give more protection than 1 or 2 natural infections. The duration of protection is highly uncertain but has only impact on the predicted reduction in rotavirus burden for values lower than 10 y. The 2 vaccine mechanism structures fit equally well with the clinical trial data. Long-term postvaccination dynamics cannot be predicted reliably with the data available.

CONCLUSION

Accounting for the joint uncertainty of several vaccine characteristics resulted in more insight into which of these are crucial for determining the impact of rotavirus vaccination. Data for up to at least 10 y postvaccination and covering older children and adults are crucial to address remaining questions on the impact of widespread rotavirus vaccination.

Hospital bed occupancy for rotavirus and all cause acute gastroenteritis in two Finnish hospitals before and after the implementation of the national rotavirus vaccination program with RotaTeq®

Background

Vaccination-impact studies of the live-attenuated pentavalent oral vaccine Rotateq® have demonstrated that the burden of rotavirus gastroenteritis has been reduced significantly after the introduction of RotaTeq® vaccination, but less is known about the benefit of this vaccination on hospital overcrowding.

Methods

As part of an observational surveillance conducted during the RV seasons 2000/2001 to 2011/2012, we analysed hospital discharge data collected retrospectively from two Finnish hospitals (Oulu and Tampere), concerning ICD 10 codes A00-09 (acute gastroenteritis, AGE) and A08.0 (rotaviral acute gastroenteritis RV AGE). We estimated the reduction in the number of beds occupied and analysed the bed occupancy rate, for RV AGE and all cause AGE, among 0–16 year-old children, before and after the implementation of the RV immunisation program.

Results

The rate of bed days occupied for RV AGE was reduced by 86% (95% CI 66%-94%) in Tampere and 79% (95% CI 47%-92%) in Oulu after RV vaccination implementation. For all cause AGE, reduction was 50% (95% CI 29% to 65%) in Tampere and 70% (95% CI 58% to 79%) in Oulu. Results were similar among 0–2 year-old children. This effect was also observed on overcrowding in both hospitals, with a bed occupancy rate for all cause AGE >25% in only 1% of the time in Tampere and 9% in Oulu after the implementation of the immunisation program, compared to 13% and 48% in the pre-vaccination period respectively. After extrapolation to the whole country, the annual number of prevented hospitalizations for all cause AGE in the post-vaccination period in Finland was estimated at 1,646 and 2,303 admissions for 0–2 and 0–16 year-old children respectively.

Conclusions

This study demonstrated that universal RV vaccination is associated with a clear decrease in the number of bed days and occupancy rates for RV AGE and all cause AGE. Positive consequences include increase in quality of care and a better healthcare management during winter epidemics.

Incidence of rotavirus and circulating genotypes in Northeast Brazil during 7 years of national rotavirus vaccination

Background and Aims

Rotavirus causes severe diarrhoea and Brazil introduced the Rotarix G1P[8] vaccine in 2006. We aimed to describe changes in rotavirus incidence and diarrhoea epidemiology before and after vaccine introduction.

Methods

Design: (i) hospital-based survey of children with diarrhoea (2006–2012); (ii) diarrhea-mortality and hospitalization surveillance (1999–2012).

Setting

(i) Aracaju and (ii) state and national level.

Results

1841 children were enrolled and 231 (12.5%) had rotavirus. Rotavirus was less frequent from January-June than from July-December (9.4% versus 20.9%, p<0.01), but the seasonal variation was less defined after 2009. Very few rotavirus cases (8–3.9%) were detected in 2011, with an increase in 2012 (13–18.5%). In 2006, unvaccinated children were more likely to have rotavirus, but thereafter unvaccinated and vaccinated children had equally low incidence. Older children and those with rotavirus were more likely to have severe diarrhea episodes. The most frequent genotype from 2006 to 2010 was G2P[4]; except in 2009, when most cases were G1P[8]. Very few G2P[4] were detected from 2011 and 50% cases in 2012 were G8P[4]. Diarrhoea-hospitalizations decreased nationally from 89,934 (2003) to 53,705 (2012; 40.3% reduction) and in the state from 1729 to 748 (56.7% reduction). Diarrhoea-deaths decreased nationally from 4368 in 1999 to 697 in 2012 (84% reduction, p<0.001) and in the state from 132 to 18 (86% reduction). These changes were much larger after vaccine introduction.

Conclusions

The vaccine was associated with substantial reductions in rotavirus incidence and diarrhoea-hospitalizations and deaths. The G2P[4] genotype predominance disappeared over time and may be replaced by other heterotypic genotypes.

Rotavirus genotypes in Belarus, 2008-2012

This study describes group A rotavirus (RVA) genotype prevalence in Belarus from 2008 to 2012. In 2008, data from 3 sites in Belarus (Brest, Mogilev, Minsk) indicated that G4P[8] was the predominant genotype. Data from Minsk (2008-2012) showed that G4P[8] was the predominant RVA genotype in all years except in 2011 when G3P[8] was most frequently detected. Other RVA genotypes common in Europe (G1P[8], G2P[4]) were detected each year of the study. This study reveals the dominance of genotype G4P[8] in Belarus and helps to establish the baseline genotype prevalence prior to RVA vaccine introduction in the country.

Impact of rotavirus vaccine on premature infants

Infants born preterm are at a higher risk of complications and hospitalization in cases of rotavirus diarrhea than children born at term. We evaluated the impact of a rotavirus vaccination campaign (May 2007 to May 2010) on hospitalizations for rotavirus gastroenteritis in a population of children under 3 years old born prematurely (before 37 weeks of gestation) in the Brest University Hospital birth zone. Active surveillance from 2002 to 2006 and a prospective collection of hospitalizations for rotavirus diarrhea were initiated in the pediatric units of Brest University Hospital until May 2010. Numbers of hospitalizations for rotavirus diarrhea among the population of children born prematurely, before and after the start of the vaccination program, were compared using a Poisson regression model controlling for epidemic-to-epidemic variation. A total of 217 premature infants were vaccinated from 2007 to 2010. Vaccine coverage for a complete course of three doses was 41.9%. The vaccine safety in premature infants was similar to that in term infants. The vaccination program led to a division by a factor of 2.6 (95% confidence interval [CI], 1.3 to 5.2) in the number of hospitalizations for rotavirus diarrhea during the first two epidemic seasons following vaccine introduction and by a factor of 11 (95% CI, 3.5 to 34.8) during the third season. We observed significant effectiveness of the pentavalent rotavirus vaccine on the number of hospitalizations in a population of prematurely born infants younger than 3 years of age. A multicenter national study would provide better assessment of this impact. (This study [Impact of Systematic Infants Vaccination Against Rotavirus on Gastroenteritis Hospitalization: a Prospective Study in Brest District, France (IVANHOE)] has been registered at ClinicalTrials.gov under registration no. NCT00740935.).