Report of the ‘European Expert Meeting on Rotavirus Vaccination’, Tampere, Finland, 19–20 May 2009

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).

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.

The unpredictable diversity of co-circulating rotavirus types in Europe and the possible impact of universal mass vaccination programmes on rotavirus genotype incidence

This article reviews the incidence of group A rotavirus (RV) types isolated from children with acute gastroenteritis (AGE) in European countries during the last 5-10 years, with the aim of establishing an overview of RV diversity before the introduction of universal mass vaccination (UMV) programmes against RV disease in most European countries. Consistent with findings from previous surveys, a high degree of diversity of co-circulating RV types exists in different locations of Europe, and over different RV seasons. Whilst RV UMV can potentially change the diversity of co-circulating genotypes, there are at present insufficient data for Europe to come to firm conclusions. Even in countries outside Europe, with several years of RV surveillance following the introduction of RV UMV (Brazil, Australia, USA), it is not clear whether changes observed in the diversity of particular RV types are due to natural fluctuations or immunological pressure exerted by RV UMVs. Consequently, it will be very difficult for European countries that have RV UMVs to conclude whether incidence changes of RV types in children with AGE are driven by immune pressures from vaccination or simply reflect natural temporal and spatial fluctuations. Whilst the monitoring of co-circulating RV strains should be continued, it should be acknowledged that the licensed monovalent and pentavalent RV vaccines are similarly effective in developed countries and that levels of RV type-specific neutralising antibodies after RV vaccination are only partially correlated with the degree of protection achieved; therefore, the significance of RV diversity for RV vaccination may be less important than is often assumed.

A hospital based study on inter- and intragenotypic diversity of human rotavirus A VP4 and VP7 gene segments, Germany

BACKGROUND

Efforts to reduce the impact of group A rotaviruses on human morbidity and mortality rely on oral immunisation with live attenuated or recombinant vaccines. A major challenge in immunisation is the vast inter- and intragenotypic diversity accomplished by circulating rotaviruses.

OBJECTIVES

To monitor rotavirus inter- and intragenotypic diversity in hospitalised children.

STUDY DESIGN

From January 2008 to December 2009 stool samples from 1994 paediatric in-patients suffering from diarrhoea were screened for rotavirus. Rotavirus G- and P-genotypes were determined by nucleotide sequencing and phylogenetic analysis was performed.

RESULTS

Rotavirus A was detected in stool samples of 341 children, comprising G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], as well as uncommon G12P[6] genotypes and mixed infections. Predominant strains shifted from G1P[8] and G9P[8] genotypes in the first season to G3P[8] and G4P[8] genotypes in the second season. The highest intragenotypic diversity was detected in G1 strains and consisted of co-circulating G1-Ic, G1-Id, G1-Ie and G1-II rotaviruses. The G2 analysis revealed different intragenotypic lineages: G2-IIa, G2-IIb and G2-IIc. Interestingly, the circulating G4-Ib rotaviruses were characterised by insertions of 3 or 6 additional coding nucleotides within variable region 4 of VP7. Whereas different G9-III VP7 gene segments were detected G3-Ia sequences were highly homologous. In the VP4 analysis P[8]-III gene segment predominated over P[4]-Vb, P[8]-I, P[8]-IV and P[6]-I.

CONCLUSIONS

A remarkable rotavirus heterogeneity was detected in the limited local setting and time span. Continued monitoring and nucleotide sequencing is necessary to document possible effects of rising immunisation levels on intragenotypic rotavirus diversity.

Pentavalent rotavirus vaccine (RotaTeq): a review of its use in the prevention of rotavirus gastroenteritis in Europe

In Europe, rotavirus gastroenteritis is associated with a significant health, economic and social burden, as it is responsible for large numbers of hospitalizations and other healthcare encounters among infants and children, as well as numerous days of work lost by parents and caregivers. RotaTeq is a three-dose, orally administered, live, pentavalent human-bovine reassortant rotavirus vaccine used for the active immunization of infants for prevention of rotavirus gastroenteritis. The protective efficacy of RotaTeq has been evaluated in terms of its effects on the incidence of rotavirus gastroenteritis and on healthcare resource use. Clinical trial data from REST (a randomized, double-blind, placebo-controlled, multinational study in approximately 70,000 healthy infants aged 6-12 weeks) and various subgroup analyses, including a large European cohort, have shown that RotaTeq may be administered at the same time as various other routine vaccines, has high and sustained efficacy covering the main period of risk for rotavirus gastroenteritis, has early protective efficacy after the first and second doses, reduces rotavirus gastroenteritis-associated hospitalization and emergency department and physician visits, and is generally well tolerated. Moreover, RotaTeq has demonstrated efficacy against the five most prevalent serotypes of rotavirus in Europe (G1-G4, G9), in terms of reductions in associated healthcare resource use. There is also evidence that the widespread use of RotaTeq may provide herd immunity, as it appears to have indirect benefits in older, unvaccinated children. Reports on the 'real world' effectiveness of RotaTeq in Europe are just emerging, but data from the US have shown a rapid and marked reduction in rotavirus burden nationwide during the approximately 2-year period following the introduction of RotaTeq and the subsequent availability of official recommendations advocating universal use of the vaccine as part of routine childhood immunization. Similar benefits have also been demonstrated in Australia after the introduction of a publicly funded rotavirus vaccination programme. Postmarketing surveillance data from the US have not identified any concerns, such as an association with intussusception or Kawasaki disease, related to the safety of RotaTeq. In conclusion, RotaTeq is a generally well tolerated vaccine that has efficacy against the five most prevalent serotypes of rotavirus in Europe and provides sustained efficacy over the main risk period for rotavirus gastroenteritis in infants and children, reducing hospitalizations and emergency department visits by decreasing the incidence and severity of illness.

Nosocomial Rotavirus Gastroenteritis in pediatric patients: a multi-center prospective cohort study

Background

Few data are available on the incidence of nosocomial Rotavirus infections (NRVI) in pediatric hospitals and on their economic impact. The goals of this study were: to evaluate the incidence of NRVI in various Italian pediatric wards during the course of two peak RV seasons; to investigate possible risk factors for NRVI; to estimate the costs caused by NRVI.

Methods

prospective cohort study. Population: all the children under 30 months of age who were admitted without any symptom or diagnosis of gastroenteritis in the pediatric hospitals of Florence, Naples, Brescia and Ancona, Italy, during the winter-spring periods 2006-2007 and 2007-2008. Serial RV rapid tests and clinical monitoring were carried out on the cohort. Telephone interviews were performed from 3 to 5 days after discharge.

Results

520 out of 608 children completed the study (85.6%). The overall incidence of NRVI was 5.3% (CI95% 3.6-7.5), (7.9 per 1,000 days of hospital stay, CI 95% 5.3-11.3). The average duration of hospital stay was significantly longer for children who had NRVI (8.1 days, SD 5.4) than for non-infected children (6.4 days, SD 5.8, difference 1.7 days, p = 0.004). The risk of contracting NRVI increased significantly if the child stayed in hospital more than 5 days, RR = 2.8 (CI95% 1.3-6), p = 0.006. In Italy the costs caused by NRVI can be estimated at 8,019,155.44 Euro per year. 2.7% of the children hospitalized with no gastroenteritis symptoms tested positive for RV.

Conclusions

Our study showed a relevant incidence of NRVI, which can increase the length of the children's stay in hospital. Limiting the number of nosocomial RV infections is important to improve patients' safety as well as to avoid additional health costs.