Reduction in pediatric rotavirus-related hospitalizations after universal rotavirus vaccination in Belgium

Measuring the Vaccine Success Index: A Framework for Long-Term Economic Evaluation and Monitoring in the Case of Rotavirus Vaccination

New vaccination programs measure economic success through cost-effectiveness analysis (CEA) based on an outcome evaluated over a certain time frame. The reimbursement price of the newly approved vaccine is then often reliant on a simulated ideal effect projection because of limited long-term data availability. This optimal cost-effectiveness result is later rarely adjusted to the observed effect measurements, barring instances of market competition-induced price erosion through the tender process. However, comprehensive and systematic monitoring of the vaccine effect (VE) for the evaluation of the real long-term economic success of vaccination is critical. It informs expectations about vaccine performance with success timelines for the investment. Here, an example is provided by a 15-year assessment of the rotavirus vaccination program in Belgium (RotaBIS study spanning 2005 to 2019 across 11 hospitals). The vaccination program started in late 2006 and yielded sub-optimal outcomes. Long-term VE surveillance data provided insights into the infection dynamics, disease progression, and vaccine performance. The presented analysis introduces novel conceptual frameworks and methodologies about the long-term economic success of vaccination programs. The CEA evaluates the initial target vaccination population, considering vaccine effectiveness compared with a historical unvaccinated group. Cost-impact analysis (CIA) covers a longer period and considers the whole vaccinated and unvaccinated population in which the vaccine has direct and indirect effects. The economic success index ratio of CIA over CEA outcomes evaluates long-term vaccination performance. Good performance is close to the optimal result, with an index value ≤1, combined with a low CEA. This measurement is a valuable aid for new vaccine introductions. It supports the establishment of robust monitoring protocols over time.

Rotavirus vaccination as a public health strategy to reduce the burden of hospitalization: The field experience of Italy (2008-2018)

Rotavirus (RV) infection is a leading cause of severe diarrhea among children younger than 5 years old and a considerable cause of RV gastroenteritis (RVGE) hospitalization. This study aimed to evaluate the impact of vaccination in Italy in the reduction of the burden of RV-related disease, estimating the relation between vaccination coverage and hospitalization rates. RVGE-related hospitalizations that occurred in Italy from 2008 to 2018 among children aged 0-35 months were assessed by consulting the Hospital Discharge Record database and including records whose ICD-9-CM diagnosis code was 008.61 in the first or in any diagnosis position. In the 2008-2018 period, a total of 17 535 791 at-risk person-years were considered and 74 211 (423.2 cases × 100 000 per year) RVGE hospitalizations were observed. Higher hospitalization rates occurred in males (456.6 vs. 387.9 × 100 000 per year) and in children aged 1 year (507.8 × 100 000 per year). Poisson regression analysis showed a decrease of -1.25% in hospitalization rates (-1.19% to -1.31%, p < 0.001) per unit increase in vaccination coverage. This is the first study that correlates hospitalization rate reduction with a percentage increase in vaccination coverage. Our findings strongly support RV vaccination as an effective public health strategy for reducing RVGE-related hospitalizations.

Attitudes and Beliefs towards Rotavirus Vaccination in a Sample of Italian Women: A Cross-Sectional Study

(1) Background: Rotavirus is the leading cause of severe diarrhea and dehydration in infants and young children worldwide. Despite the proven benefits of vaccination, vaccine hesitancy and refusal remains a significant barrier to achieving high vaccination coverage in many countries, such as Italy. (2) Methods: An online survey was conducted among women aged between 18 and 50 years from Abruzzo Region, Italy. The survey was composed of two main sections: demographic characteristics and attitudes and knowledge about rotavirus vaccination, based on a five-point Likert scale. Logistic regression analysis was performed to evaluate factors associated with willingness to get the rotavirus vaccination. (3) Results: A total of 414 women were enrolled in the study. Women who were unaware of rotavirus more frequently had a lower education level (university degree 62.5% vs. 78.7%, p = 0.004) and reported having no children (p < 0.001). About half of the enrolled women thought that rotavirus infection is dangerous (190, 55.6%) and that rotavirus can cause a serious illness (201, 58.8%). Regarding associated factors, women informed by a physician were more likely get a vaccination compared to women informed by friends or relatives (OR 34.35, 95% CI 7.12-98.98, p < 0.001). (4) Conclusions: The present study showed low levels of knowledge and attitudes towards rotavirus vaccination. These results highlight the need for developing and improving additional public education programs for parents.

The Economic Value of Rotavirus Vaccination When Optimally Implemented in a High-Income Country

Rotavirus vaccination was introduced in high-income countries starting in 2006, with no recommendation for optimal implementation. Economic evaluations were presented before launch projecting potential impacts. Few economic reassessments have been reported following reimbursement. This study compares the short- to long-term economic value of rotavirus vaccination between pre-launch predictions and real-world evidence collected over 15 years, proposing recommendations for optimal vaccine launch. A cost-impact analysis compared rotavirus hospitalisation data after the introduction of vaccination between pre-launch modelled projections and observed data collected in the RotaBIS study in Belgium. A best model fit of the observed data was used to simulate launch scenarios to identify the optimal strategy. Data from other countries in Europe were used to confirm the potential optimal launch assessment. The Belgian analysis in the short term (first 8 years) indicated a more favourable impact for the observed data than predicted pre-launch model results. The long-term assessment (15 years) showed bigger economic disparities in favour of the model-predicted scenario. A simulated optimal vaccine launch, initiating the vaccination at least 6 months prior the next seasonal disease peak with an immediate very high vaccine coverage, indicated important additional potential gains, which would make vaccination very cost impactful. Finland and the UK are on such a route leading to long-term vaccination success, whereas Spain and Belgium have difficulties in achieving optimum vaccine benefits. An optimal launch of rotavirus vaccination may generate substantial economic gains over time. For high-income countries that are considering implementing rotavirus vaccination, achieving an optimal launch is a critical factor for long-term economic success.

Established and new rotavirus vaccines: a comprehensive review for healthcare professionals

Robust scientific evidence related to two rotavirus (RV) vaccines available worldwide demonstrates their significant impact on RV disease burden. Improving RV vaccination coverage may result in better RV disease control. To make RV vaccination accessible to all eligible children worldwide and improve vaccine effectiveness in high-mortality settings, research into new RV vaccines continues. Although current and in-development RV vaccines differ in vaccine design, their common goal is the reduction of RV disease risk in children <5 years old for whom disease burden is the most significant. Given the range of RV vaccines available, informed decision-making is essential regarding the choice of vaccine for immunization. This review aims to describe the landscape of current and new RV vaccines, providing context for the assessment of their similarities and differences. As data for new vaccines are limited, future investigations will be required to evaluate their performance/added value in a real-world setting.

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.

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 .

Defining the Recipe for an Optimal Rotavirus Vaccine Introduction in a High-Income Country in Europe

Observational data over 15 years of rotavirus vaccine introduction in Belgium have indicated that rotavirus hospitalisations in children aged <5 years plateaued at a higher level than expected, and was followed by biennial disease peaks. The research objective was to identify factors influencing these real-world vaccine impact data. We constructed mathematical models simulating rotavirus-related hospitalisations by age group and year for those children. Two periods were defined using different model constructs. First, the vaccine uptake period encompassed the years required to cover the whole at-risk population. Second, the post-uptake period covered the years in which a new infection/disease equilibrium was reached. The models were fitted to the observational data using optimisation programmes with regression and differential equations. Modifying parameter values identified factors affecting the pattern of hospitalisations. Results indicated that starting vaccination well before the peak disease season in the first year and rapidly achieving high coverage was critical in maximising early herd effect and minimising secondary sources of infection. This, in turn, would maximise the reduction in hospitalisations and minimise the size and frequency of subsequent disease peaks. The analysis and results identified key elements to consider for countries initiating an optimal rotavirus vaccine launch programme.

Explaining the formation of a plateau in rotavirus vaccine impact on rotavirus hospitalisations in Belgium

BACKGROUND

Observational data on the reduction in hospitalisations after rotavirus vaccine introduction in Belgium suggest that vaccine impact plateaued at an unexpectedly high residual hospitalisation rate. The objective of this analysis was to identify factors that influence real-world vaccine impact.

METHODS

Data were collected on hospitalisations in children aged ≤ 5 years with rotavirus disease from 11 hospitals since 2005 (the RotaBIS study). The universal rotavirus vaccination campaign started late in 2006. A mathematical model simulated rotavirus hospitalisations in different age groups using vaccine efficacy and herd effect, influenced by vaccine coverage, vaccine waning, and secondary infection sources. The model used optimisation analysis to fit the simulated curve to the observed data, applying Solver add-in software. It also simulated an 'ideal' vaccine introduction maximising hospitalisation reduction (maximum coverage, maximum herd effect, no waning), and compared this with the best-fit simulated curve. Modifying model input values identified factors with the largest impact on hospitalisations.

RESULTS

Compared with the 'ideal' simulation, observed data showed a slower decline in hospitalisations and levelled off after three years at a higher residual hospitalisation rate. The slower initial decline was explained by the herd effect in unvaccinated children. The higher residual hospitalisation rate was explained by starting the vaccine programme in November, near the rotavirus seasonal peak. This resulted in low accumulated vaccine coverage during the first rotavirus disease peak season, with the consequential appearance of secondary infection sources. This in turn reduced the herd effect, resulting in a diminished net impact.

CONCLUSIONS

Our results indicate that countries wishing to maximise the impact of rotavirus vaccination should start vaccinating well ahead of the rotavirus seasonal disease peak. This maximises herd effect during the first year leading to rapid and high reduction in hospitalisations. Secondary infection sources explain the observed data in Belgium better than vaccine waning.

Rotavirus disease and health care utilisation among children under 5 years of age in highly developed countries: A systematic review and meta-analysis

BACKGROUND

Rotavirus (RV) infection is the leading cause of diarrhoea-associated morbidity and mortality globally among children under 5 years of age. RV vaccination is available, but has not been implemented in many national immunisation plans, especially in highly developed countries. This systematic review aimed to estimate the prevalence and incidence of health care use for RV gastroenteritis (RVGE) among children aged under 5 years in highly developed countries without routine RV vaccination.

METHODS

We searched MEDLINE and Embase databases from January 1^st 2000 to December 17^th 2018 for publications reporting on incidence or prevalence of RVGE-related health care use in children below 5 years of age: primary care and emergency department (ED) visits, hospitalisations, nosocomial infections and deaths. We included only studies with laboratory-confirmed RV infection, undertaken in highly developed countries with no RV routine vaccination plans. We used random effects meta-analysis to generate summary estimates with 95% confidence intervals (CI) and prediction intervals.

RESULTS

We screened 4033 abstracts and included 74 studies from 21 countries. Average incidence rates of RVGE per 100 000 person-years were: 2484 (95% CI 697-5366) primary care visits, 1890 (1597-2207) ED visits, 500 (422-584) hospitalisations, 34 (20-51) nosocomial infections and 0.04 (0.02-0.07) deaths. Average proportions of cases of acute gastroenteritis caused by RV were: 21% (95% CI 16-26%) for primary care visits; 32% (25-38%) for ED visits; 41% (36-47%) for hospitalisations, 29% (25-34%) for nosocomial infections and 12% (8-18%) for deaths. Results varied widely between and within countries, and heterogeneity was high (I² > 90%) in most models.

CONCLUSION

RV in children under 5 years causes many healthcare visits and hospitalisations, with low mortality, in highly developed countries without routine RV vaccination. The health care use estimates for RVGE obtained by this study can be used to model RV vaccine cost-effectiveness in highly developed countries.

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.

Concomitant administration of a liquid formulation of human rotavirus vaccine (porcine circovirus-free) with routine childhood vaccines in infants in the United States: Results from a phase 3, randomized trial

BACKGROUND

In response to the detection of porcine circovirus type 1 (PCV-1) in the human rotavirus vaccine (HRV), a PCV-free HRV (no detection of PCV-1 and PCV-2 according to the detection limit of tests used) was developed. Liquid (Liq) PCV-free HRV previously showed immunogenicity and safety profiles comparable to lyophilized (Lyo) HRV.

METHODS

This was a phase 3a, randomized, single-blind study (NCT03207750) conducted in the United States. Healthy infants aged 6-12 weeks received 2 doses (0, 2 months) of either Liq PCV-free HRV or Lyo HRV with routine vaccines (0, 2, 4 months): diphtheria-tetanus-acellular pertussis, hepatitis B and inactivated poliovirus combination vaccine (DTaP-HBV-IPV), monovalent tetanus toxoid-conjugated vaccine against Haemophilus influenzae type b (Hib-TT), and 13-valent pneumococcal conjugate vaccine. Co-primary objectives were: (i) to assess non-inferiority of immune responses to routine vaccine antigens 1 month post-dose 3 following co-administration with Liq PCV-free HRV compared to Lyo HRV; (ii) to rule out a 10% decrease in seroresponse to pertussis antigens after dose 3. Other objectives were to evaluate immunogenicity and safety of HRV vaccines.

RESULTS

Of 1272 vaccinated infants, 990 (489 in Liq PCV-free HRV and 501 in Lyo HRV group) were included in the per-protocol set. All statistical criteria were met, thus co-primary objectives were demonstrated. Seroprotection/seropositivity rates in both groups were high: 100% for diphtheria/tetanus, ≥99.3% for HBV, ≥99.8% for polio, ≥99.8% for each pertussis antigen, ≥90.8% for all pneumococcal serotypes except serotype 3 (≥69.1%), and ≥ 97.4% for Hib. Most infants seroconverted for anti-RV antibodies (76.3% of Liq PCV-free HRV and 78.9% of Lyo HRV recipients). Geometric mean concentrations/titers were comparable between groups. Incidences of adverse events and serious adverse events were similar between groups.

CONCLUSION

Routine pediatric vaccines co-administered with Liq PCV-free HRV showed non-inferior immune responses and similar safety profiles to those following co-administration with Lyo HRV.

Occurrence of severe rotavirus gastroenteritis in children younger than three years of age before and after the introduction of rotavirus vaccine: a prospective observational study in four pediatric clinics in Shibata City, Niigata Prefecture, Japan

In Japan, rotavirus (RV) vaccines have already been introduced but not used for universal vaccination as of 2018. Therefore, we identified cases of severe rotavirus gastroenteritis (RVGE) in children younger than three years of age and investigated the occurrence of infection before and after the introduction of RV vaccines. An ecological study through prospective surveillance was conducted in four pediatric clinics in Shibata City, Niigata Prefecture, Japan, during the 2011 to 2018 RVGE epidemic seasons. We divided the study period into three eras: pre-vaccine introduction era (2011), low-mid coverage transitional era (2012 to 2014, RV vaccine coverage rate: 32.9–56.5%), and high coverage plateau era (2015 to 2018, 67.7–81.7%). In this study, the incidence rate of severe RVGE was significantly lower in the plateau era than in the pre-vaccine introduction and transitional eras. Furthermore, the hospitalization rate due to RVGE in Shibata City was lower in the plateau era than in the pre-vaccination introduction and transitional eras. The number of hospitalizations due to RVGE in subjects who required or did not require intravenous rehydration at the pediatric clinics significantly decreased with the increase in vaccine coverage rates by more than 70% in the plateau era.

Fifteen years of experience with the oral live-attenuated human rotavirus vaccine: reflections on lessons learned

INTRODUCTION

Rotavirus (RV) disease remains a prominent cause of disease burden in children <5 years of age worldwide. However, implementation of RV vaccination has led to significant reductions in RV mortality, compared to the pre-vaccination era. This review presents 15 years of real-world experience with the oral live-attenuated human RV vaccine (HRV; Rotarix). HRV is currently introduced in ≥80 national immunization programs (NIPs), as 2 doses starting from 6 weeks of age.

AREAS COVERED

The clinical development of HRV and post-marketing experience indicating the impact of HRV vaccination on RV disease was reviewed.

EXPERT OPINION

In clinical trials, HRV displayed an acceptable safety profile and efficacy against RV-gastroenteritis, providing broad protection against heterotypic RV strains by reducing the consequences of severe RV disease in infants. Real-world evidence shows substantial, rapid reduction in the number of RV infections and associated hospitalizations following introduction of HRV in NIPs, regardless of economic setting. Indirect effects against RV disease are also observed, such as herd protection, decrease in nosocomial infections incidence, and a reduction of disease-related societal/healthcare costs. However, not all countries have implemented RV vaccination. Coverage remains suboptimal and should be improved to maximize the benefits of RV vaccination.

Immunogenicity and safety of porcine circovirus-free human rotavirus vaccine in healthy infants: a phase III, randomized trial

BACKGROUND

Porcine circovirus type 1 (PCV-1) material was detected in the human rotavirus vaccine (HRV) in 2010. In this study (NCT02914184) we compared immunogenicity and safety of the PCV-free HRV vaccine (PCV-free HRV) with HRV. PCV-free HRV is an HRV with no detection of PCV-1 and PCV-2 according to the limit of detection of the tests used.

METHODS

Healthy infants 6-12 weeks of age were randomized (1:1:1:1) to receive 2 doses of 1 of the 3 lots of PCV-free HRV or HRV. The study objectives were to demonstrate lot-to-lot consistency of the PCV-free HRV and non-inferiority of PCV-free HRV as compared to HRV in terms of immunogenicity, 1-2 months post-dose 2. Reactogenicity and safety were also assessed.

RESULTS

Overall, 1612 infants were enrolled and 1545 completed the study. Study objectives were demonstrated since the pre-defined criteria were met. Among participants receiving PCV-free HRV and HRV, 79.27% and 81.76% seroconverted and geometric mean concentrations were 159.5 and 152.8 U/mL, respectively. The incidences of adverse events and serious adverse events were similar between the pooled PCV-free HRV and HRV groups.

CONCLUSIONS

The 3 PCV-free HRV lots demonstrated consistency and PCV-free HRV was non-inferior compared to HRV in terms of immunogenicity.

Evidence of the impact of monovalent rotavirus vaccine on childhood acute gastroenteritis hospitalization in Togo

BACKGROUND

Monovalent rotavirus vaccine (RV1) was introduced in the immunization schedule of Togo in June 2014. We evaluated the impact of rotavirus vaccines on acute gastroenteritis (AGE) and rotavirus-associated hospitalizations in Togolese children.

METHODS

Sentinel surveillance for AGE (defined as ≥3 liquid or semi-liquid stools/24 h lasting <7 days) hospitalizations among children <5 years of age was conducted in two sites in the capital city, Lome. ELISA was used for diagnosis of rotavirus infection in children with AGE. Additionally, review of hospitalization registers was performed at five hospitals to assess trends in AGE hospitalizations among children aged <5 years. For the vaccine impact assessment, pre-rotavirus vaccine introduction (July 2010-June 2014) and post-rotavirus vaccine introduction (July 2014-June 2016) periods were compared for annual changes in proportions of hospitalizations associated with AGE and rotavirus.

RESULTS

During the pre-vaccine period, sentinel surveillance showed that 1017 patients were enrolled and 57% (range, 53-62%) tested positive for rotavirus, declining to 42% (23% reduction) in the first post-vaccine year and to 26% (53% reduction) in the second post-vaccine year; declines were most marked among infants. The patient register review showed that, compared with pre-vaccine rotavirus seasons, declines in hospitalizations due to all-cause AGE during post-vaccine rotavirus seasons were 48% among <1 year age-group in both first and second years following vaccine introduction. Among 1-4 year olds no reduction was noted in the first year and a 19% decline occurred in the second year.

CONCLUSIONS

We report rapid and marked reduction in the number of AGE hospitalizations and the proportion of AGE hospitalizations attributable to rotavirus in the first two years post- RV1 implementation in Togo. It is necessary to monitor long-term vaccine impact on rotavirus disease burden through continued surveillance.

Universal rotavirus vaccination program in Sicily: Reduction in health burden and cost despite low vaccination coverage

Rotavirus is considered the main cause of severe gastroenteritis and nosocomial infections in Pediatric units, especially during late winter and early spring season in temperate region. In 2013 Sicilian Region, for the first time in Italy, introduced universal Rotavirus vaccination. This study aims to estimate health and economic impact on rotavirus Gastroenteritis (RVGE) among children aged 0–59 months in Sicily, after rotavirus vaccine introduction.

We analyzed hospital discharge records including a diagnosis of RVGE occurred from 1^st January 2009 to 31^st December 2016 among hospitalized children aged 0 to 59 months, residents in Sicily. RVGEs were defined as all hospitalizations with an ICD-9-CM diagnosis code of 008.61 on first or any diagnosis position. Also an economic impact analysis on Health Regional System was conducted.

We observed a consistent decline of hospitalization after rotavirus vaccination introduction from 394 per 100,000 in 2009–2012 to 220 per 100,000 in 2013–2016. We found a change in the peak of reported cases by at least one month from March-April in the pre-vaccination period to May-June in the post-vaccination period. Since 2013, we estimated that the annual average cost saved is 1,134,056 € when considering direct and indirect costs to health care as well as vaccination costs.

Our study is the first analysis conducted as far as we are aware in a high-income setting with poor coverage (lower than 50%), demonstrating a significant reduction of RVGE hospitalizations in Sicily after vaccine introduction. Moreover, was observed a consistent impact of vaccination on health care cost saving.

Indirect Rotavirus Vaccine Effectiveness for the Prevention of Rotavirus Hospitalization: A Systematic Review and Meta-Analysis

Two rotavirus vaccines, RotaTeq and Rotarix, are licensed for global use; however, the protection they confer to unvaccinated individuals through indirect effects remains unknown. We systematically reviewed the literature and quantified indirect rotavirus vaccine effectiveness (VE) for preventing rotavirus hospitalization in children aged less than 5 years. From 148 identified abstracts, 14 studies met our eligibility criteria. In our main analysis using a random-effects model, indirect rotavirus VE was 48% (95% confidence interval [CI]: 39-55%). In a subgroup analysis by country income level, indirect VE was greater in high-income countries (52%; 95% CI: 43-60%) than in low- and middle-income countries (LMICs) (25%; 95% CI: 5-41%). In a sensitivity analysis using a quality-effects model, the indirect VE in LMICs was not statistically significant (25%; 95% CI: 0-44%). Our findings highlight the importance of increasing rotavirus vaccine coverage, particularly in LMICs where evidence for indirect VE is limited and rotavirus burden is high.

A review of recommendations for rotavirus vaccination in Europe: Arguments for change

BACKGROUND

More than 10 years after the authorisation of two rotavirus vaccines of demonstrated efficacy and with a strongly positive benefit-risk profile, uptake in Europe remains low. Only 13 countries in Europe provide a fully-funded rotavirus universal mass vaccination (UMV) programme, three provide a partially-funded programme, and one provides full funding for a reduced programme targeting at-risk infants. Around 40% of countries in Europe currently have no existing recommendations for rotavirus vaccine use in children from the national government.

METHODS

We provide an overview of the status of rotavirus vaccine recommendations across Europe and the factors impeding uptake. We consider the evidence for the benefits and risks of vaccination, and argue that cost-effectiveness and cost-saving benefits justify greater access to rotavirus vaccines for infants living in Europe.

RESULTS

Lack of awareness of the direct and indirect burden caused by rotavirus disease, potential cost-saving from rotavirus vaccination including considerable benefits to children, families and society, and government/insurer cost constraints all contribute to complacency at different levels of health policy in individual countries.

CONCLUSIONS

More than 10 years after their introduction, available data confirm the benefits and acceptable safety profile of infant rotavirus UMV programmes. Europe serves to gain considerably from rotavirus UMV in terms of reductions in healthcare resource utilization and related costs in both vaccinated subjects and their unvaccinated siblings through herd protection.

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.

Update on the epidemiology of rotavirus in the Middle East and North Africa

Rotavirus (RV) is the leading cause of severe acute gastroenteritis (AGE) worldwide. Consequently, we conducted a systematic literature review on articles studying RV in the 25 countries of the MENA region during the past 15years (2000-2015). The methods and reporting were set according to the 2015 preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) and based on the elements from the international prospective register of systematic reviews (PROSPERO). Our literature search identified 169 studies meeting our predefined inclusion criteria. Studies reporting on RV were conducted in 19 out of the 24 countries of the MENA region. The largest number of studies was reported in Turkey (n=32), Iran (n=31), Saudi Arabia (n=19) and Egypt (n=17). The majority of studies reporting on RV gastroenteritis rates were clinical observational studies. In 115 studies out of 169, RV was reported among in-patients whereas 35 studies reported RV among outpatients. The predominantly reported RV genotype in the region was G1[P8] followed by G2[P4] and G9[P8]. The majority of studies (n=108) were conducted among children less than 5years of age whereas the remaining studies reported on AGE among other age groups and rarely adults. In MENA countries, RV infection was reported all year round with peaks described in cold as well as hot months. This systematic review provides a current update on the epidemiology of RV-associated gastroenteritis in countries of the MENA region and draws attention to the major gaps existing in the continuous monitoring of RV.

Impact of rotavirus vaccine on all-cause diarrhea and rotavirus hospitalizations in Madagascar

BACKGROUND

Rotavirus vaccine was introduced into the Extended Program on Immunization in Madagascar in May 2014. We analyzed trends in prevalence of all cause diarrhea and rotavirus hospitalization in children <5years of age before and after vaccine introduction and assessed trend of circulating rotavirus genotypes at Centre Hospitalier Universitaire Mère Enfant Tsaralalàna (CHU MET).

METHODS

From January 2010 to December 2016, we reviewed the admission logbook to observe the rate of hospitalization caused by gastroenteritis among 19619 children <5years of age admitted at the hospital. In June 2013-December 2016, active rotavirus surveillance was also conducted at CHUMET with support from WHO. Rotavirus antigen was detected by EIA from stool specimen of children who are eligible for rotavirus gastroenteritis surveillance at sentinel site laboratory and rotavirus positive specimens were further genotyped at Regional Reference Laboratory by RT-PCR.

RESULTS

Diarrhea hospitalizations decreased after rotavirus vaccine introduction. The median proportion of annual hospitalizations due to diarrhea was 26% (range: 31-22%) before vaccine introduction; the proportion was 25% the year of vaccine introduction, 17% in 2015 and 16% in 2016. Rotavirus positivity paralleled patterns observed in diarrhea. Before vaccine introduction, 56% of stool specimens tested positive for rotavirus; the percent positive was 13% in 2015, 12% in 2016. Diverse genotypes were detected in the pre-vaccine period; the most common were G3P[8] (n=53; 66%), G2P[4] (n=12; 15%), and G1P[8] (n=11; 14%). 6 distinct genotypes were found in 2015; the most common genotype was G2P[4] (n=10; 67%), the remaining, 5, G12[P8], G3[P8], G1G3[P4], G3G12[P4][P8] and G1G3[NT] had one positive specimen each.

CONCLUSIONS

Following rotavirus vaccine introduction all-cause diarrhea and rotavirus-specific hospitalizations declined dramatically. The most common genotypes detected in the pre-vaccine period were G3P[8] and G2P[4] in 2015, the post vaccine period.

Risk of intussusception following rotavirus vaccination: An evidence based meta-analysis of cohort and case-control studies

BACKGROUND

International post-licensure studies on rotavirus vaccines have identified an increased risk of intussusception in infants after administration. The first developed rotavirus vaccine (Rotashield (RRV-TV)) was suspended post-licensure in 1999 after an association with intussusception was found. The currently available second-generation rotavirus vaccines (Rotateq (RV5) and Rotarix (RV1)), are recommended as a routine vaccine by the World Health Organisation (WHO). Post-licensure studies of these vaccines have shown a smaller but temporal increased risk for developing intussusception.

METHODS

A meta-analysis was performed to summarise available evidence and to give an overall risk of developing intussusception from case-control and cohort studies for all rotavirus vaccines that have been manufactured up to date. A search was conducted on MEDLINE, PubMed, EMBASE and Google Scholar up to May 2017. Eligible studies assessed the relationship between the rotavirus vaccine administration and subsequent development of intussusception both after receiving the first dose and after receiving all doses combined. Data was extracted on study characteristics, methods and outcomes. Results were pooled using the random-effect model.

RESULTS

Six cohort studies involving 4506265 total first doses and five case-control studies involving a total sample of 9643 children were included in this analysis. The cohort data revealed that there was an associated increased risk of intussusception after the first 7days post first dose of the vaccine (RR:3.71, 95% CI:1.08-12.69) and after receiving all doses of the rotavirus vaccine (RR:3.47, 95% CI:1.23-9.78). Similarly, the case-control data found an increased risk of intussusception following the first dose (OR: 8.45, 95% CI: 4.08-17.50) and following all doses (OR: 1.59, 95% CI: 1.11-2.27).

CONCLUSIONS

Findings of this meta-analysis suggest that the rotavirus vaccine is associated with an increased risk on the development of intussusception, principally seen after administration of the first dose of vaccine.

Sustained low rotavirus activity and hospitalisation rates in the post-vaccination era in Belgium, 2007 to 2014

In 2006, Belgium was the first country in the European Union to recommend rotavirus vaccination in the routine infant vaccination schedule and rapidly achieved high vaccine uptake (86-89% in 2007). We used regional and national data sources up to 7 years post-vaccination to study the impact of vaccination on laboratory-confirmed rotavirus cases and rotavirus-related hospitalisations and deaths. We showed that (i) from 2007 until 2013, vaccination coverage remained at 79-88% for a complete course, (ii) in children 0-2 years, rotavirus cases decreased by 79% (95% confidence intervals (CI): 68--89%) in 2008-2014 compared to the pre-vaccination period (1999--2006) and by 50% (95% CI: 14-82%) in the age group ≥ 10 years, (iii) hospitalisations for rotavirus gastroenteritis decreased by 87% (95% CI: 84-90%) in 2008--2012 compared to the pre-vaccination period (2002--2006), (iv) median age of rotavirus cases increased from 12 months to 17 months and (v) the rotavirus seasonal peak was reduced and delayed in all post-vaccination years. The substantial decline in rotavirus gastroenteritis requiring hospitalisations and in rotavirus activity following introduction of rotavirus vaccination is sustained over time and more pronounced in the target age group, but with evidence of herd immunity.

Lost workdays and healthcare use before and after hospital visits due to rotavirus and other gastroenteritis among young children in Norway

BACKGROUND

Cost-effectiveness of rotavirus vaccination is affected by assumptions used in health economic evaluations. To inform such evaluations, we assessed healthcare use before and after hospitalisations due to rotavirus and other acute gastroenteritis (AGE) among children <5years of age in Norway and estimated daycare and work absenteeism.

METHODS

We conducted post-discharge interviews with caregivers of 282 children hospitalised with AGE at two hospitals in Norway during April 2014-February 2017. We collected data on healthcare use and absenteeism from daycare and work. We examined healthcare seeking and absenteeism patterns for RV-specific and other gastroenteritis.

RESULTS

Caregivers of 485 (37%) of 1 298 hospitalised children were invited to participate, and 282 (58%) completed the questionnaire. Among these, 106 (38%) were rotavirus-positive, 119 (42%) were rotavirus-negative, and for 57 (20%) children no rotavirus testing was performed. Overall, 97% of children had been in contact with a healthcare provider before hospital admission and 28% had contacted a healthcare provider after discharge. Children that attended daycare were absent from daycare for a mean of 6.3days (median 5days). Caregivers of these children reported work absenteeism in 74% of cases. The mean duration of work absenteeism among caregivers was 5.9days (median 5days) both for RV-positive and RV-negative cases.

CONCLUSION

In Norway, work absenteeism and healthcare use before and after hospitalisation due to rotavirus and non-rotavirus gastroenteritis are considerable and impose an economic burden on the healthcare system and society.

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.

The Sustained Rotavirus Vaccination Impact on Nosocomial Infection, Duration of Hospital Stay, and Age: The RotaBIS Study (2005-2012)

Introduction

The benefits of rotavirus (RV) vaccination in developed countries have focused on reductions in mortality, hospitalization and medical visits, and herd protection. We investigated other aspects related to RV-induced nosocomial infection, duration of hospital stay, age shift, and sustained vaccine impact (VI) over time.

Method

RotaBIS (Rotavirus Belgian Impact Study; ClinicalTrials.gov identifier, NCT01563146) annually collects retrospective data on hospitalization linked to RV testing in children up to 5 years old from 11 pediatric wards located all over Belgium. Data from 2005 to 2012 have been split in pre- (2005–2006) and post-vaccination (2007–2012) period. Information was collected on age, gender, RV test result, nosocomial infection caused by RV and duration of hospital stay.

Results

Over the 6-year period after the introduction of the RV vaccine, an 85% reduction in nosocomial infections was observed (221 in 2005 to 33 in 2012, p < 0.001). A significant reduction of almost 2 days in average duration of hospital stay per event was observed overall (7.62 days in 2005 to 5.77 days in 2012, p < 0.001). The difference is mainly explained by the higher reduction in number of nosocomial infections. A pronounced age shift (+24%, p < 0.01) of RV nosocomial infection to infants ≤2 months old was observed, increasing with length of post-vaccination period. VI was maintained over the follow-up (±79% VI per birth cohort). A decrease was seen depending on age, 85% (95% CI 76–91%) in the youngest to 63% (95% CI 22–92%) in the oldest age group.

Conclusion

The higher reduction in nosocomial infection may affect the overall average duration of hospital stay for RV infection. No change in VI by birth cohort, but a reduction by age group was observed. These findings could be important for decision-makers considering the introduction of universal mass RV vaccination programs.

Trial registration

ClinicalTrials.gov identifier, NCT01563146.

Funding

GlaxoSmithKline Biologicals SA (Rixensart, Belgium).

Rotavirus vaccination and intussusception - Science, surveillance, and safety: A review of evidence and recommendations for future research priorities in low and middle income countries

As of January 2016, 80 countries have introduced rotavirus vaccines into their national immunization programs. Many have documented significant declines in rotavirus-specific and all-cause diarrheal illnesses following vaccine introduction. Two globally licensed rotavirus vaccines have been associated with a low risk of intussusception in several studies. In July 2014, the Rotavirus Organization of Technical Allies Council convened a meeting of research and advocacy organizations, public health experts, funders, and vaccine manufacturers to discuss post-marketing intussusception surveillance and rotavirus vaccine impact data. Meeting objectives were to evaluate updated data, identify and prioritize research gaps, discuss best practices for intussusception monitoring in lower-income settings and risk communication, and provide insight to country-level stakeholders on best practices for intussusception monitoring and communication. Meeting participants agreed with statements from expert bodies that the benefits of vaccination with currently available rotavirus vaccines outweigh the low risk of vaccination-associated intussusception. However, further research is needed to better understand the relationship of intussusception to wild-type rotavirus and rotavirus vaccines and delineate potential etiologies and mechanisms of intussusception. Additionally, evidence from research and post-licensure evaluations should be presented with evidence of the benefits of vaccination to best inform policymakers deciding on vaccine introduction or vaccination program sustainability.

Precise reply and clarifications on behalf of Sicilian Public Health Authorities to the case report published by La Rosa and collegues

As a results of the case report “Post-rotavirus vaccine intussusception in identical twins: a case report” recently published on Human Vaccines & Immunotherapy by La Rosa et al., the principal Sicilian Public Health Authorities decided to specify several points and underline some important details omitted by the authors. In particular, aims to underline the remarkable benefit for Sicilian Regional Health service after the introduction of the rotavirus vaccination. Universal mass vaccination against rotavirus is properly managed by the Regional Health Authorities and is contributing to a consistent increase of public health in the Sicilian pediatric population; any modification of such a program should be based on robust scientific evidences. Finally, a single case report should not be considered as a basis to recommend a change in the clinical practice but instead a possible point of start for discussion and research.

Reply letter and clarifications on behalf of La Rosa and colleagues to Sicilian Public Health Authorities

In May 2016 we published in the journal Human Vaccines and Immunotherapy. 1 79 80 the case-report "Post-rotavirus vaccine intussusception in identical twins: a case report." We received a reply letter from "Sicilian Public Health Authorities" that placed attention to some points of our work. We would like to do some clarifications.

Epidemiological trends for hospital admissions for acute rotavirus gastroenteritis in Belgium following the introduction of routine rotavirus vaccination and the subsequent switch from lyophilized to liquid formulation of Rotarix™

This study describes epidemiological trends for acute rotavirus gastroenteritis (RVGE) in Belgium in children aged ⩽5 years during the period June 2007 to May 2014 after the introduction of routine rotavirus (RV) vaccination. This period encompassed the switch from lyophilized to the liquid formulation of Rotarix™ (GlaxoSmithKline, Belgium) in August 2011. Uptake of RV vaccine remained consistently high throughout the study period with Rotarix the brand most often used. RV was present in 9% (1139/12 511) of hospitalized cases with acute gastroenteritis included in the study. Epidemiological trends for hospital admissions for RVGE remained consistent throughout the study period, with no evidence of any change associated with the switch from lyophilized to liquid formulation of Rotarix. This suggests both formulations perform similarly, with the liquid formulation not inferior regarding ability to reduce hospital admissions for acute RVGE in children aged ⩽5 years. A strong seasonal effect was observed with most RVGE occurring in the winter months but with some variability in intensity, with highest incidence found in those aged 6–24 months. The main observation was the decreased number of hospital admissions for RVGE in Belgium that occurred during winter 2013/2014.

A significant and consistent reduction in rotavirus gastroenteritis hospitalization of children under 5 years of age, following the introduction of universal rotavirus immunization in Israel

Universal rotavirus vaccination with RotaTeq was introduced in Israel in December 2010. We examined hospitalization rates of children under 5 years of age due to all-cause and rotavirus gastroenteritis, both before and 3 years after universal introduction of the vaccination. An ongoing hospital-based surveillance network that was established in November 2007, accessed information regarding hospitalization of children due to gastroenteritis (n = 6205) in 3 hospitals in northern Israel, with an annual average of about 60,000 children under 5 years of age living in the catchment area of these hospitals. Stool samples were tested for rotavirus by immunochromatography. Compared to the period preceding implementation of the universal rotavirus vaccination (2008-2010), hospitalizations due to rotavirus gastroenteritis in children <5 years of age decreased significantly, by 55% (95% CI 43%-67%) during the period of universal vaccination (2011-2013), a decrease that was sustained throughout the 3 year period. This reduction was greater in children aged 0-23 months (60-61%) than in toddlers aged 24-59 months (36%). A 32% (95% CI 21%-45%) decrease in the incidence of all-cause gastroenteritis was also observed. During the period preceding universal vaccination, rotavirus diarrhea showed typical winter seasonality, with highest incidence in December. However, the winter peak was substantially blunted during the period of universal immunization. Surveillance of rotavirus gastroenteritis should continue to assess the long-term impact of such a program. Our findings are of relevance to high and middle-income countries considering the introduction of a universal rotavirus immunization program.

Improvement in hospital Quality of Care (QoC) after the introduction of rotavirus vaccination: An evaluation study in Belgium

During each winter period hospital emergency rooms and pediatric wards are often overwhelmed by high patient influx with infectious diseases leading to chaotic conditions with poor quality of care (QoC) delivery as a consequence. The conditions could be improved if we were able to better control the influx by introducing for instance better prevention strategies against some of the most frequent infectious diseases. New prevention strategies using vaccination against rotavirus infection were introduced in Belgium in November 2006. We developed a measure of hospital QoC suitable for assessing the impact of pediatric rotavirus vaccination. The study is retrospective collecting routine data on bed and staff management in one pediatric hospital in Belgium. The data were divided in pre- and post-vaccination periods during rotavirus-epidemic and non-epidemic periods. The scores were constructed using Explanatory Factor Analysis (EFA). All patients enrolled were admitted to the pediatric ward over the period from 1 January 2004 to 31 December 2009. The results of the epidemic period indicated that bed-day occupancy, bed-day turnover and unplanned readmissions for acute gastroenteritis were lower in the post-vaccination compared with the pre-vaccination periods. The QoC scores were therefore significantly lower (indicating improved QoC) after the introduction of rotavirus vaccination, compared with pre-vaccination. The data suggests that the reduction in the winter peak of rotavirus-related hospitalizations after the introduction of the vaccine reduces pressure on hospital resources and improves the quality of hospital care. The findings should be further tested in similar settings.

Population-Level Impact of Ontario's Infant Rotavirus Immunization Program: Evidence of Direct and Indirect Effects

OBJECTIVE

To evaluate the direct and indirect population impact of rotavirus (RV) immunization on hospitalizations and emergency department (ED) visits for acute gastroenteritis (AGE) in Ontario before and after the publicly-funded RV immunization program.

METHODS

Administrative data was used to identify ED visits and hospitalizations for all Ontarians using ICD-10 codes. We used two outcome definitions: RV-specific AGE (RV-AGE) and codes representing RV-, other viral and cause unspecified AGE ("overall AGE"). The pre-program and public program periods were August 1, 2005 to July 31, 2011; and August 1, 2011 to March 31, 2013, respectively. A negative binominal regression model that included the effect of time was used to calculate rates and rate ratios (RRs) and 95% confidence intervals (CIs) for RV-AGE and overall AGE between periods, after adjusting for age, seasonality and secular trends. Analyses were conducted for all ages combined and age stratified.

RESULTS

Relative to the pre-program period, the adjusted RRs for RV-AGE and overall AGE hospitalizations in the public program period were 0.29 (95%CI: 0.22-0.39) and 0.68 (95%CI: 0.62-0.75), respectively. Significant reductions in RV-AGE hospitalizations were noted overall and for the following age bands: < 12 months, 12-23 months, 24-35 months, 3-4 years, and 5-19 years. Significant declines in overall AGE hospitalizations were observed across all age bands, including older adults > = 65 years (RR 0.80, 95%CI: 0.72-0.90). The program was associated with adjusted RRs of 0.32 (95% CI: 0.20-0.52) for RV-AGE ED visits and 0.90 (95% CI: 0.85-0.96) for overall AGE ED visits.

CONCLUSIONS

This large, population-based study provides evidence of the impact of RV vaccine in preventing hospitalizations and ED visits for RV-AGE and overall AGE, including herd effects.

Health Impact of Rotavirus Vaccination in Developing Countries: Progress and Way Forward

Two rotavirus vaccines have been licensed in >100 countries worldwide since 2006. As of October 2105, these vaccines have been implemented in the national immunization programs of 79 countries, including 36 low-income countries that are eligible for support for vaccine purchase from Gavi, the Vaccine Alliance. Rotavirus vaccines were initially introduced in Australia and countries of the Americas and Europe after completion of successful clinical trials in these regions, and the impact of routine vaccination in reducing the health burden of severe childhood gastroenteritis in these regions has been well documented. Because of concerns around the performance of orally administered rotavirus vaccines in developing countries, vaccine implementation in these settings only began after additional clinical trials were completed and the World Health Organization issued a global recommendation for use of rotavirus vaccines in 2009. This supplementary issue of Clinical Infectious Diseases includes a collection of articles describing the impact and effectiveness of routine rotavirus vaccination in developing countries that were among the early adopters of rotavirus vaccine. The data highlight the benefits of vaccination and should provide valuable evidence to sustain vaccine use in these countries and encourage other countries to adopt routine rotavirus vaccination to reduce the health burden of severe childhood gastroenteritis.

Use of Patients With Diarrhea Who Test Negative for Rotavirus as Controls to Estimate Rotavirus Vaccine Effectiveness Through Case-Control Studies

BACKGROUND

Case-control studies are often performed to estimate postlicensure vaccine effectiveness (VE), but the enrollment of controls can be challenging, time-consuming, and costly. We evaluated whether children enrolled in the same hospital-based diarrheal surveillance used to identify rotavirus cases but who test negative for rotavirus (test-negative controls) can be considered a suitable alternative to nondiarrheal hospital or community-based control groups (traditional controls).

METHODS

We compared calculated VE estimates as a function of varying values of true VE, attack rates of rotavirus and nonrotavirus diarrhea in the population, and sensitivity and specificity of the rotavirus enzyme immunoasssay. We also searched the literature to identify rotavirus VE studies that used traditional and test-negative control groups and compared VE estimates obtained using the different control groups.

RESULTS

Assuming a 1% attack rate for severe rotavirus diarrhea, a 3% attack rate for severe nonrotavirus diarrhea in the population, a test sensitivity of 96%, and a specificity of 100%, the calculated VE estimates using both the traditional and test-negative control groups closely approximated the true VE for all values from 30% to 100%. As true VE decreased, the traditional case-control approach slightly overestimated the true VE and the test-negative case-control approach slightly underestimated this estimate, but the absolute difference was only ±0.2 percentage points. Field VE estimates from 10 evaluations that used both traditional and test-negative control groups were similar regardless of control group used.

CONCLUSIONS

The use of rotavirus test-negative controls offers an efficient and cost-effective approach to estimating rotavirus VE through case-control studies.

Impact of vaccination uptake on hospitalizations due to rotavirus acute gastroenteritis in 2 different socioeconomic areas of Spain

Rotavirus is the leading cause of hospitalization due to acute gastroenteritis (AGE) in infants and toddlers. However, rotavirus vaccination has been associated with a decline in hospitalization rates due to rotavirus AGE. A descriptive retrospective study was conducted to analyze the impact of rotavirus vaccination on the rate of hospitalizations due to AGE among children ≤2 years old in 2 areas of the province of Almería, Spain. After eight years of rotavirus vaccination, rates of hospitalizations due to rotavirus AGE are diminished. This decline is closely related to vaccine coverage in the studied areas.

Diversity in Rotavirus-Host Glycan Interactions: A "Sweet" Spectrum

Interaction with cellular glycans is a critical initial step in the pathogenesis of many infectious agents. Technological advances in glycobiology have expanded the repertoire of studies delineating host glycan-pathogen interactions. For rotavirus, the VP8* domain of the outer capsid spike protein VP4 is known to interact with cellular glycans. Sialic acid was considered the key cellular attachment factor for rotaviruses for decades. Although this is true for many rotavirus strains causing infections in animals, glycan array screens show that many human rotavirus strains bind nonsialylated glycoconjugates, called histo-blood group antigens, in a strain-specific manner. The expression of histo-blood group antigens is determined genetically and is regulated developmentally. Variations in glycan binding between different rotavirus strains are biologically relevant and provide new insights into multiple aspects of virus pathogenesis such as interspecies transmission, host range restriction, and tissue tropism. The genetics of glycan expression may affect susceptibility to different rotavirus strains and vaccine viruses, and impact the efficacy of rotavirus vaccination in different populations. A multidisciplinary approach to understanding rotavirus-host glycan interactions provides molecular insights into the interaction between microbial pathogens and glycans, and opens up new avenues to translate findings from the bench to the human population.

Effect of pentavalent rotavirus vaccine introduction on hospital admissions for diarrhoea and rotavirus in children in Rwanda: a time-series analysis

BACKGROUND

In May, 2012, Rwanda became the first low-income African country to introduce pentavalent rotavirus vaccine into its routine national immunisation programme. Although the potential health benefits of rotavirus vaccination are huge in low-income African countries that account for more than half the global deaths from rotavirus, concerns remain about the performance of oral rotavirus vaccines in these challenging settings.

METHODS

We conducted a time-series analysis to examine trends in admissions to hospital for non-bloody diarrhoea in children younger than 5 years in Rwanda between Jan 1, 2009, and Dec 31, 2014, using monthly discharge data from the Health Management Information System. Additionally, we reviewed the registries in the paediatric wards at six hospitals from 2009 to 2014 and abstracted the number of total admissions and admissions for diarrhoea in children younger than 5 years by admission month and age group. We studied trends in admissions specific to rotavirus at one hospital that had undertaken active rotavirus surveillance from 2011 to 2014. We assessed changes in rotavirus epidemiology by use of data from eight active surveillance hospitals.

FINDINGS

Compared with the 2009-11 prevaccine baseline, hospital admissions for non-bloody diarrhoea captured by the Health Management Information System fell by 17-29% from a pre-vaccine median of 4051 to 2881 in 2013 and 3371 in 2014, admissions for acute gastroenteritis captured in paediatric ward registries decreased by 48-49%, and admissions specific to rotavirus captured by active surveillance fell by 61-70%. The greatest effect was recorded in children age-eligible to be vaccinated, but we noted a decrease in the proportion of children with diarrhoea testing positive for rotavirus in almost every age group.

INTERPRETATION

The number of admissions to hospital for diarrhoea and rotavirus in Rwanda fell substantially after rotavirus vaccine implementation, including among older children age-ineligible for vaccination, suggesting indirect protection through reduced transmission of rotavirus. These data highlight the benefits of routine vaccination against rotavirus in low-income settings.

FUNDING

Gavi, the Vaccine Alliance and the Government of Rwanda.

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.

Value of Post-Licensure Data on Benefits and Risks of Vaccination to Inform Vaccine Policy: The Example of Rotavirus Vaccines

In 1999, the first rhesus-human reassortant rotavirus vaccine licensed in the U.S. was withdrawn within a year of its introduction after it was linked with intussusception at a rate of ~1 excess case per 10,000 vaccinated infants. While clinical trials of 60,000-70,000 infants of each of the two current live oral rotavirus vaccines, RotaTeq (RV5) and Rotarix (RV1), did not find an association with intussusception, post-licensure studies have documented a risk in several high and middle income countries, at a rate of ~1-6 excess cases per 100,000 vaccinated infants. However, considering this low risk against the large health benefits of vaccination that have been observed in many countries, including in countries with a documented vaccine-associated intussusception risk, policy makers and health organizations around the world continue to support the routine use of RV1 and RV5 in national infant immunization programs. Because the risk and benefit data from affluent settings may not be directly applicable to developing countries, further characterization of any associated intussusception risk following rotavirus vaccination as well as the health benefits of vaccination is desirable for low income settings.

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.

Dissecting the indirect effects caused by vaccines into the basic elements

Vaccination directly protects vaccinated individuals, but it also has the potential for indirectly protecting the unvaccinated in a population (herd protection). Unintended negative consequences such as the re-manifestation of infection, mainly expressed as age shifts, result from vaccination programs as well. We discuss the necessary conditions for achieving optimal herd protection (i.e., high quality vaccine-induced immunity, substantial effect on the force of infection, and appropriate vaccine coverage and distribution), as well as the conditions under which age shifts are likely to occur. We show examples to illustrate these effects. Substantial ambiguity in observing and quantifying these indirect vaccine effects makes accurate evaluation troublesome even though the nature of these outcomes may be critical for accurate assessment of the economic value when decision makers are evaluating a novel vaccine for introduction into a particular region or population group. More investigation is needed to identify and develop successful assessment methodologies for precisely analyzing these outcomes.

Intussusception and Monovalent Rotavirus Vaccination in Singapore: Self-Controlled Case Series and Risk-Benefit Study

OBJECTIVE

To investigate the association between monovalent human rotavirus vaccine (RV1) and intussusception among Asian infants and the impact of older age of vaccination. To perform risk-benefit analysis of RV1 vaccination programs in Singapore.

STUDY DESIGN

We performed a self-controlled case series by extracting intussusception cases in infants aged <12 months from hospital databases (2005-2012) and with vaccination histories from a national immunization registry. Relative incidences were calculated by comparing incidence during defined risk periods after vaccination with times outside these periods. In the risk benefit analysis, we estimated excess intussusception hospitalization in relation to the number of infants vaccinated for hypothetical vaccination coverage scenarios.

RESULTS

There were 86 infants hospitalized with intussusception; 20 cases had received at least 1 dose of RV1. Nearly all (19) had received their first dose at age >12 weeks old. The age-adjusted relative incidence of intussusception in the 1- to 7-day period post dose one was 8.36 (95% CI 2.42-28.96). Of all childhood hospitalizations because of rotavirus, 71% (570 cases) could be prevented with 90% vaccination coverage. There would be approximately 1 excess intussusception case per 65,000 infants vaccinated.

CONCLUSIONS

Risk of intussusception increases about 8-fold during 1-7 days after receipt of first dose RV1 in infants of Chinese, Malay, and Indian ethnicity in Singapore, Asia. High vaccine coverage program in Singapore would be beneficial with only a low risk of excess intussusception. The relative risk of intussusception post-RV1 vaccination is not higher in Asia despite differences in background intussusception incidence compared with US and Australia, or older age of vaccination.

Exploring the potential impact of rotavirus vaccination on work absenteeism among female administrative personnel of the City of Antwerp through a retrospective database analysis

OBJECTIVES

Rotavirus vaccination has been reimbursed in Belgium since November 2006 with a high uptake (>85%). Economic analyses of the vaccine have been reported, including estimates of indirect cost gain related to the reduction in work absenteeism. The objective of this study was to evaluate the latter parameter using real-life data.

DESIGN AND SETTING

A simple model estimated the reduction in absent workdays per working mother with a firstborn baby after the introduction of the rotavirus vaccine. Next, data on work absences were retrospectively analysed (from 2003 to 2012) using a database of administrative employees (n=11,600 working women per year) in the City of Antwerp. Observed reductions in absenteeism after the introduction of the vaccine were compared with the results from the model. These reductions would most likely be observed during the epidemic periods of rotavirus (from January to the end of May) for short-duration absences of ≤ 5 days. We compared data from outside epidemic periods (from June to December), expecting no changes over time prevaccine and postvaccine introduction, as well as with a control group of women aged 30-35 years with no first child.

RESULTS

Model estimates were 0.73 working days gained per working mother. In the database of the City of Antwerp, we identified a gain of 0.88 working days during the epidemic period, and an accumulated gain of 2.24 days over a 3-year follow-up period. In the control group, no decrease in absenteeism was measured. Giving vaccine access to working mothers resulted in an estimated accumulated net cost gain of €187 per mother.

CONCLUSIONS

Reduction in absenteeism among working mothers was observed during periods of the epidemic after the introduction of the rotavirus vaccine in Belgium. This reduction is in line with estimates of indirect cost gains used in economic evaluations of the rotavirus vaccine.

TRIAL REGISTRATION NUMBER

HO-12-12768.