Efficacy of human rotavirus vaccine against rotavirus gastroenteritis during the first 2 years of life in European infants: randomised, double-blind controlled study

Epidemiology of rotavirus infection among young children with acute diarrhoea in Burkina Faso

BACKGROUND

In anticipation of vaccine introduction, we assessed epidemiology of rotavirus disease among children visiting medical centre due to acute diarrhoea in Ouagadougou, Burkina Faso.

METHODS

Between November 2008 and February 2010, stool specimens from 447 children less than 5 years of age suffering from diarrhoea were tested for the presence of rotavirus by antigen detection using an immunochromatographic test. Sociodemographic, environmental and clinical factors were assessed during the study.

RESULTS

Rotavirus antigen was detected in 151 (33.8%) of the patients. Most of the cases (94.2%) were in children < 24 months of age. Fever and vomiting were the symptoms most commonly reported in association with rotavirus diarrhoea and the patients were often hospitalized. Rotavirus-associated diarrhoea occurred mostly during the season from December to April (dry season). Rotavirus infection was significantly less frequent in breast-fed than among bottle-fed babies.

CONCLUSIONS

The results of this study underscore the need to control rotavirus infections among young children in Burkina Faso and may argue a decision on the introduction of rotavirus vaccine in Burkina Faso.

Global impact of rotavirus vaccines

The WHO has recently recommended the inclusion of rotavirus vaccine in the national immunization programs of all countries. In countries in the Americas, Europe and Australia that have adopted routine childhood immunization against rotavirus, significant reductions in the burden of severe childhood diarrhea have been observed. Besides protecting vaccinated children, disease rates also appear to be reduced in unvaccinated children, suggesting indirect benefits from vaccination (i.e., herd protection). Early clinical trial data from Africa and Asia are promising, and further efforts are needed to optimize the benefits of vaccination in developing countries where vaccines are likely to have their greatest impact.

Hospitalisation for rotavirus gastroenteritis in the paediatric population in the Veneto Region, Italy

BACKGROUND

This study evaluates the epidemiological impact of RVGE hospitalisation in the Veneto Region during the period spanning from 2000-2007 along with the associated costs. The analysis was conducted in an area where rotavirus vaccination is not included into immunization programmes and is an attempt to assess the potential benefits of such introduction.

METHODS

To update the estimates of acute RVGE hospitalisation rates in children ≤5 years in the Veneto Region, we conducted an 8 year retrospective observational population-based analysis (2000-2007).

RESULTS

Over the study period, a total of 4,119 admissions for RVGE were reported, with a mean hospital stay of 3.5 days. The population-based hospitalisation RVGE incidence rate was 195.8 per 100,000 children aged ≤5 years (lower than other European countries).

CONCLUSIONS

RVGE is an important cause of paediatric hospitalisation in the Veneto Region. The data reaffirm the substantial burden of rotavirus hospitalisations in children and the potential health benefits of the vaccination as well as the possibility of adding rotavirus vaccination to the current schedule.

Recommendations for the use of rotavirus vaccines in infants

Rotavirus infection occurs in the majority of healthy children before five years of age, and is the most common diarrheal illness associated with hospitalization. The majority of children present with symptoms of vomiting, diarrhea and fever. As a result, rotavirus gastroenteritis is responsible for greater morbidity than other common childhood diarrheal illnesses. The highest risk of severe disease is in children younger than two years of age. It is estimated that one in 20 children will require an emergency department visit. In addition to community-acquired infections, hospital-acquired infections are also significant. There are currently two licensed rotavirus vaccines in Canada. Both vaccines are administered orally and are highly effective against severe disease and hospitalization. Large pre- and postmarketing studies have shown no increased risk of intussusception with the current rotavirus vaccines. The present statement provides information concerning the clinical disease and rotavirus vaccines in Canada.

[Toward the elimination of rotavirus gastroenteritis by universal vaccination]

Rotavirus is the most important cause of severe gastroenteritis in children worldwide, and is most effectively controlled by vaccines. The Strategic Advisory Group of Experts (SAGE) of the World Health Organization (WHO) recommended, in 2009, the inclusion of rotavirus vaccination of infants into all national immunization programs. Two, live, orally-administrable vaccines are licensed globally. They are Rotarix, a G1P[8] monovalent, human rotavirus-based vaccine (GlaxoSmithKline), and RotaTeq, a pentavalent, bovine-human reassortant vaccine (Merck). Although the two vaccines are very different in antigenic composition and administration schedule, they are almost equally safe with respect to intussusception and 90-100% efficacious against severe rotavirus diarrhea. Countries where either vaccine was introduced into the national childhood immunization program have witnessed not only a drastic decrease in the number of rotavirus hospitalizations but a near 50% reduction in the number of all-cause-diarrhea hospitalizations. Rotavirus diarrhea, an emerging infectious disease because of its discovery in 1973, may now be among vaccine preventable diseases.

The cost-effectiveness of rotavirus vaccination in Malawi

BACKGROUND

Rotarix (GlaxoSmithKline), a newly licensed rotavirus vaccine requiring 2 doses, may have the potential to save hundreds of thousands of lives in Africa. Nations such as Malawi, where Rotarix is currently under phase III investigation, may nevertheless face difficult economic choices in considering vaccine adoption.

METHODS

The cost-effectiveness of implementing a Rotarix vaccine program in Malawi was estimated using published estimates of rotavirus burden, vaccine efficacy, and health care utilization and costs.

RESULTS

With 49.5% vaccine efficacy, a Rotarix program could avert 2582 deaths annually. With GAVI Alliance cofinancing, adoption of Rotarix would be associated with a cost of $5.07 per disability-adjusted life-year averted. With market pricing, Rotarix would be associated with a base case cost of $74.73 per disability-adjusted life-year averted. Key variables influencing results were vaccine efficacy, under-2 rotavirus mortality, and program cost of administering each dose.

CONCLUSIONS

Adopting Rotarix would likely be highly cost-effective for Malawi, particularly with GAVI support. This finding holds true across uncertainty ranges for key variables, including efficacy, for which data are becoming available.

Prevention of rotavirus gastroenteritis in infants and children: rotavirus vaccine safety, efficacy, and potential impact of vaccines

Rotavirus infection is the most common cause of severe gastroenteritis globally, with greater than 86% of deaths occurring in low-income and middle-income countries. There are two rotavirus vaccines currently licensed in the United States and prequalified by the World Health Organization. RV1 is a monovalent attenuated human rotavirus strain, given orally in two doses. RV5 is a pentavalent human-bovine reassortant rotavirus vaccine, given orally in three doses. A third rotavirus vaccine, LLV, is a lamb rotavirus strain given orally as a single dose, which is currently available only in China. RV1 and RV5 have been shown to be highly efficacious in developed countries, and initial results from trials in Africa and Asia are promising as well. At least three other vaccines are in development, which are being developed by manufacturers of developing countries. Further studies are needed to clarify issues including administration of oral rotavirus vaccines with breastfeeding and other oral vaccines, and alterations in dosing schedule. Using new data on global diarrheal burden, rotavirus is estimated to cause 390,000 deaths in children younger than 5 years. Should rotavirus vaccines be introduced in the routine immunization programs of all countries, a potential of 170,000 deaths could be prevented annually. The largest impact on mortality would be seen in low-income and middle-income countries, despite poor immunization coverage and lower efficacy. Therefore, international efforts are needed to ensure that rotavirus vaccines reach the populations with highest burden of rotavirus disease.

Rotavirus infections and vaccines: burden of illness and potential impact of vaccination

Rotaviruses are the most common cause of severe gastroenteritis in children. By 5 years of age virtually every child worldwide will have experienced at least one rotavirus infection. This leads to an enormous disease burden, where every minute a child dies because of rotavirus infection and another four are hospitalized, at an annual societal cost in 2007 of $US2 billion. Most of the annual 527 000 deaths are in malnourished infants living in rural regions of low and middle income countries. In contrast, most measurable costs arise from medical expenses and lost parental wages in high income countries. Vaccines are the only public health prevention strategy likely to control rotavirus disease. They were developed to mimic the immunity following natural rotavirus infection that confers protection against severe gastroenteritis and consequently reduces the risk of primary healthcare utilization, hospitalization and death. The two currently licensed vaccines--one a single human strain rotavirus vaccine, the other a multiple strain human-bovine pentavalent reassortant rotavirus vaccine--are administered to infants in a two- or three-dose course, respectively, with the first dose given at 6-14 weeks of age. In various settings they are safe, immunogenic and efficacious against many different rotavirus genotypes. In high and middle income countries, rotavirus vaccines confer 85-100% protection against severe disease, while in low income regions of Africa and Asia, protection is less, at 46-77%. Despite this reduced efficacy in low income countries, the high burden of diarrheal disease in these regions means that proportionately more severe cases are prevented by vaccination than elsewhere. Post-licensure effectiveness studies show that rotavirus vaccines not only reduce rotavirus activity in infancy but they also decrease rates of rotavirus diarrhea in older and unimmunized children. A successful rotavirus vaccination program will rely upon sustained vaccine efficacy against diverse and evolving rotavirus strains and efficient vaccine delivery systems. The potential introduction of rotavirus vaccines into the world's poorest countries with the greatest rates of rotavirus-related mortality is expected to be very cost effective, while rotavirus vaccines should also be cost effective by international standards when incorporated into developed countries immunization schedules. Nonetheless, cost effectiveness in each country still depends largely on the local rotavirus mortality rate and the price of the vaccine in relation to the per capita gross domestic product.

Prevention and treatment of viral diarrhea in pediatrics

Diarrhea is the second largest cause of mortality worldwide in children from the perinatal period to the age of 5 years. Rotavirus has been the most commonly identified viral cause of diarrhea in children. Norovirus is now recognized as the second most common viral pathogen. Adenovirus, astrovirus and sapovirus are the other major viral causes of pediatric gastroenteritis. Strategies for prevention include basic hygiene, optimization of nutrition and, ultimately, vaccination. Two new vaccines have recently been licensed for the prevention of rotavirus, the monovalent human rotavirus vaccine (Rotarix) and the pentavalent bovine-human reassortant vaccine (RotaTeq). These vaccines have already dramatically decreased the morbidity associated with rotavirus in countries where they are widely used. Efforts to develop a norovirus vaccine face substantial hurdles. Treatment of the viral pathogens is primarily limited to symptomatic measures.

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.

Effectiveness of rotavirus vaccination against childhood diarrhoea in El Salvador: case-control study

OBJECTIVE

To evaluate the effectiveness of a monovalent rotavirus vaccine against severe rotavirus disease and to assess its impact on diarrhoea in children aged less than 2 years after national introduction in El Salvador, a low-middle income country in Central America.

DESIGN

Matched case-control study.

SETTING

Seven hospitals in cities across El Salvador, January 2007 to June 2009.

PARTICIPANTS

323 children aged less than 2 years admitted with laboratory confirmed rotavirus diarrhoea and 969 healthy controls matched for age and neighbourhood.

MAIN OUTCOME MEASURE

Effectiveness of rotavirus vaccination ((1-adjusted odds ratio of vaccination)x100) against rotavirus diarrhoea requiring hospital admission.

RESULTS

Cases and controls were similar for breast feeding, premature birth, maternal education, and socioeconomic variables. G1P[8] strains were identified in 92% of rotavirus cases. Effectiveness of two doses of vaccination against diarrhoea requiring hospital admission was 76% (95% confidence interval 64% to 84%). Protection was significantly lower (P=0.046) among children aged 12 months or more (59%, 27% to 77%) compared with children aged 6-11 months (83%, 68% to 91%). One dose of vaccine was 51% (26% to 67%) effective. At the sentinel hospitals, all admissions for diarrhoea among children under 5 declined by 40% in 2008 and by 51% in 2009 from the prevaccine year 2006.

CONCLUSIONS

A monovalent rotavirus vaccine was highly effective against admissions for rotavirus diarrhoea in children aged less than 2 years in El Salvador and substantially reduced the number of such admissions in this low-middle income setting. The impact on disease epidemiology after vaccination, particularly among older children, warrants future attention.

Immunogenicity and safety of the human rotavirus vaccine Rotarix co-administered with routine infant vaccines following the vaccination schedules in Europe

This study assessed the immunogenicity and safety of a human rotavirus vaccine RIX4414; the effect of co-administration of childhood vaccines on the immune responses was also assessed. Healthy infants aged 6-14 weeks received two doses of RIX4414/placebo concomitantly with the primary childhood vaccination (Infanrix hexa, Infanrix quinta,Meningitec and/or Prevnar), respecting the vaccination schedule of each country. Anti-rotavirus IgA seroconversion rate (ELISA cut-off 20 U/ml) was measured pre-vaccination and 1-2 months post-Dose 2. Immune response against diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b, inactivated polio virus, pneumococcal polysaccharide conjugate (France and Germany) and meningococcal group C conjugate vaccines (Spain) were measured approximately 1-month post-Dose 3. An overall anti-rotavirus IgA seroconversion rate of 86.5%(95% CI: 83.9-88.8) was observed in the RIX4414 group 1-month post-Dose 2. The seroconversion rate in Finland and Italy (3 and 5-month schedule) was 94.6%(95% CI: 90.0-97.5) and 92.3%(95% CI: 64.0-99.8), respectively. Immune response to the childhood vaccines was unaffected following co-administration with RIX4414. Reactogenicity profile was similar for RIX4414 and placebo groups. RIX4414 was immunogenic and well tolerated in European infants and the co-administration of routine childhood vaccines with RIX4414 did not negatively impact the immune responses to these vaccines.

Evaluation of a gastroenteritis severity score for use in outpatient settings

OBJECTIVE

The objective of this study was to evaluate the internal reliability, construct validity, and ease of administration of a gastroenteritis disease severity score, the modified Vesikari score (MVS), which does not require in-person assessment.

METHODS

The MVS was created by replacing 1 variable (percent dehydration) in the original score with the need for future health care visits. We used the MVS to assess the global severity of disease in a cohort of children 3 to 48 months of age with acute gastroenteritis who were evaluated in 1 of 11 participating pediatric emergency departments. In this prospective study, caregivers recorded symptoms at home in a diary and reported the results via telephone at follow-up evaluation 14 days later. To evaluate internal reliability, we examined correlations between the items included in the score. Construct validity was evaluated by assessing the correlation between the total score and other proxy outcomes of disease severity, MVS distribution, and consistency between sites.

RESULTS

A total of 455 children were enrolled, and 415 were successfully contacted for follow-up evaluation. Internal reliability was acceptable, with Cronbach's alpha of 0.59. Disease severity was correlated with day care (P = .01) and work (P = .002) absenteeism. The MVS was normally distributed, and mean scores did not differ between the 11 sites.

CONCLUSIONS

The MVS seems to measure effectively the global severity of disease in a cohort of children with acute gastroenteritis. These data support the use of the MVS as an outcome measure in future clinical trials.

Vaccines for preventing rotavirus diarrhoea: vaccines in use

BACKGROUND

Rotavirus results in higher diarrhoea-related death in children less than five years of age than any other single agent, particularly in low- and middle-income countries. The World Health Organization has recommended the use of rotavirus vaccines in childhood immunization schedules.

OBJECTIVES

To evaluate rotavirus vaccines approved for use (Rotarix, RotaTeq, and Lanzhou Lamb Rotavirus (LLR)) for preventing rotavirus diarrhoea.

SEARCH STRATEGY

In February 2010, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (published in The Cochrane Library 2009, Issue 1), MEDLINE, EMBASE, LILACS, and BIOSIS. We also searched the ICTRP (January 2010) and checked reference lists of identified studies.

SELECTION CRITERIA

Randomized controlled trials comparing rotavirus vaccines approved for use with placebo, no intervention, or another vaccine in children.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility, extracted data, and assessed risk of bias. Dichotomous data were combined using the risk ratio (RR) and 95% confidence intervals (CI).

MAIN RESULTS

Thirty-four trials that included 175,944 participants met the inclusion criteria. They evaluated Rotarix (26 trials; 99,841 participants) and RotaTeq (eight trials; 76,103 participants), and had variable risk of bias (where information provided). None of the identified trials used LLR or compared rotavirus vaccines. Compared to placebo, Rotarix and RotaTeq were both effective at reducing rotavirus diarrhoea (severe cases and cases of any severity). They also reduced all-cause diarrhoea (severe cases), and hospitalizations and need for medical attention caused by rotavirus diarrhoea. However, few data were available for Rotarix and all-cause diarrhoea. Versus the placebo groups, participants in each vaccine group had similar numbers of deaths, serious adverse events, reactogenicity profiles (fever, diarrhoea, and vomiting), and adverse events that required discontinuation of the vaccination schedule. Both vaccines were immunogenic (measured by virus shedding in stool and/or seroconversion). Subgroup analyses indicate that both vaccines are effective in countries with different incomes, but few data are available.

AUTHORS' CONCLUSIONS

Rotarix and RotaTeq are effective vaccines for the prevention of rotavirus diarrhoea. The balance between benefit and harm favours benefit. Ongoing safety monitoring should be continued. Trials comparing LLR with placebo should be conducted and the results made available.

The effect of rotavirus vaccine on diarrhoea mortality

Background Approximately 39% of the global diarrhoea deaths in children aged 5 years may be attributable to rotavirus infection. Two rotavirus vaccines were recently introduced to the market, with evidence of efficacy in the USA, Europe and Latin America. We sought to estimate the effectiveness of these vaccines against rotavirus morbidity and mortality.

Methods We conducted a systematic review of published efficacy and effectiveness trials of rotavirus vaccines. Study descriptors and outcome measures were abstracted into standardized tables and the quality of each study was graded. We performed meta-analyses for any outcome with two or more data points, and used child health epidemiology reference group (CHERG) Rules for Evidence Review to estimate the effect of the vaccine on rotavirus mortality.

Results We identified six papers for abstraction, reporting results from four studies. No studies reported diarrhoea or rotavirus deaths, but all studies showed reductions in hospitalizations due to rotavirus or diarrhoea of any aetiology, severe and any rotavirus infections and diarrhoea episodes of any aetiology in children who received rotavirus vaccine compared with placebo. Effectiveness against very severe rotavirus infection best approximated effectiveness against the fraction of diarrhoea deaths attributable to rotavirus, and was estimated to be 74% (95% confidence interval: 35–90%).

Conclusions Rotavirus vaccines are efficacious against rotavirus morbidity and mortality and have the potential to substantially reduce child mortality in low-income countries if implemented appropriately.

Universal mass vaccination against rotavirus gastroenteritis: impact on hospitalization rates in austrian children

BACKGROUND

Since July 2007, rotavirus vaccinations have been subsidized in Austria for all children from the seventh week up to the sixth month of life. Vaccination coverage over the whole period was 72% with an increase to 87% in 2008.

METHODS

In a sentinel network including 11 pediatric hospital wards in Austria, data of children up to 15 years of age and hospitalized due to rotavirus gastroenteritis between January 2001 and December 2008 have been collected.

RESULTS

The hospitalization rates of children up to 12 months of age with rotavirus gastroenteritis were 2066 x 10(-5) between 2001 and 2006 and decreased to 631 x 10(-5) in 2008. For children between 12 and 24 months of age the hospitalization rate decreased from 1822 x 10(-5) (2001-2006) to 1456 x 10(-5) in 2008. In children aged 2 to less than 5 years, incidence rates were 436 x10(-5) (2001-2006) and 461 x 10(-5) in 2008. In older children, the hospitalization rates remained unchanged. In the target population for the RV-vaccine, a decrease of hospitalization rates due to rotavirus gastroenteritis of 74% was observed compared to the era before the introduction of the vaccine. The field effectiveness of the vaccine was estimated between 61% and 98%, depending on assumptions about the vaccination status.

CONCLUSIONS

Within 18 months, the universal mass vaccination program against rotavirus led to a substantial decrease in the hospitalization rates of the target cohort of the immunization program in Austria.

Continuing impact of infectious diseases on childhood deaths in England and Wales, 2003-2005

BACKGROUND

Data on the contribution of specific infections to childhood deaths in developed countries are limited.

METHODS

Infection-related deaths in children aged 28 days to 14 years who died in England and Wales between 2003 and 2005 were identified from routine anonymized death certificate dataset provided by the Office for National Statistics to the Health Protection Agency, using predefined International Classification of Diseases codes for infection.

RESULTS

There were 1368 infection-related deaths documented, constituting 20% of all childhood deaths. An underlying medical condition was recorded in 50% (676 cases), the most common being prematurity in infants (322/660, 52%), cerebral palsy in 1 to 4 year olds (46/190, 24%), and malignancy (46/163, 28%) in 5 to 14 year olds. Of the 837 deaths where a pathogen was coded, 494 (59%) specified bacterial infection, 256 (31%) viral infection, and 69 (8%) fungal infection. Among deaths with recorded bacterial infections, a lower proportion of meningococcal and pneumococcal infections (14% [22/155] vs. 60% [205/339], P < 0.0001) and a higher proportion of Gram-negative enteric bacilli (78/155 cases [50%] vs. 17/339 cases [5%], P < 0.0001) were reported in children with and without documented underlying medical conditions, respectively.

CONCLUSIONS

Infections continue to make a major contribution to deaths in children, particularly among those with underlying conditions. Identification of the pathogens associated with childhood deaths should help prioritize the development of intervention strategies for reducing pediatric mortality. Linkage of death registrations to national infectious disease surveillance systems should be undertaken to strengthen monitoring of infectious deaths and evaluate the effect of interventions.

Clinical characteristics of rotavirus gastroenteritis in children in a medical center

BACKGROUND

Rotavirus is one of the major causes of severe gastroenteritis in infants and young children worldwide.

METHODS

We retrospectively analyzed the demographic and clinical profiles of rotavirus infection among children hospitalized in the Cathay General Hospital, Taiwan from May 2004 to April 2007. Children under 15 years of age with gastroenteritis were enrolled in the study and had stool specimens tested for the presence of rotavirus.

RESULTS

There were 238 participating patients, most of whom were aged 3-5 years (44%). The most common symptom was diarrhea (98.7%), and the peak month was May (20.4%). All patients were discharged alive with no complications.

CONCLUSION

Gastroenteritis due to rotavirus infection was found in older children between 6 and 12 years of age, as well as in hospitalized children between 3 and 5 years of age. Most cases occurred in the spring.

6th World Congress of the World Society for Pediatric Infectious Diseases (WSPID)

The 6th World Congress of the World Society for Pediatric Infectious Diseases (WSPID) was held in Buenos Aires, Argentina between 18 and 22 November, 2009. This is one of the biggest pediatric infectious disease assemblies in the world and it brought together pediatricians and pediatric infectious disease and vaccine experts. Numerous topics about pediatric infectious diseases were discussed during the congress. The scientific program focused on vaccines and vaccine-preventable diseases, including epidemiological and vaccine efficacy trials and updates on topics of childhood infectious disease. We summarize the current knowledge about some childhood vaccines and vaccine-preventable diseases, including rotavirus vaccines, conjugated pneumococcal vaccines (PCV-7, PHiD-CV and PCV-13), varicella, pertussis meningococcal and pandemic H1N1 vaccines. The next WSPID congress will be held in Melbourne, Australia between 16 and 20 November 2011.

Klebsiella pneumoniae bacteraemia complicating rotavirus gastroenteritis in two infants with glucocorticoid deficiency

Rotavirus gastroenteritis was complicated by Klebsiella Pneumoniae bacteraemia in two infants with glucocorticoid deficient conditions who were treated with 'stress dose' hydrocortisone during their illness. Delayed healing in the context of glucocorticoid administration combined with damage from rotavirus infection may result in increased risk of mucosal invasion by gastrointestinal bacteria and subsequent enteric gram-negative bacteraemia.

Update on Rotarix: an oral human rotavirus vaccine

Worldwide, rotaviruses are the single most important agents of severe gastroenteritis in infants and young children. Globally, it is estimated that every year rotavirus gastroenteritis causes more than 125 million episodes of diarrhea and nearly 527,000 deaths, mainly in developing countries. The development of new effective and safe rotavirus vaccines was recognized as the most effective intervention strategy that could yield a significant impact on the burden of rotavirus disease. Rotarix is an oral live-attenuated human rotavirus vaccine containing a single G1P[8] strain. The first oral dose may be administered as early as 6 weeks of age, with a minimum interval of 4 weeks prior to second dose; the vaccination course should be completed by the age of 24 weeks according to the manufacturer. In the USA, the upper age limit for the second dose has recently been recommended at 32 weeks of age by the Advisory Committee on Immunization Practices. The development program for Rotarix including Phase I, II and III multicenter studies involving over 100,000 infants has been established in Latin America, Europe, Asia and Africa. The vaccine proved to be well tolerated, immunogenic, efficacious, safe and not associated with intussusception. It provided 85-96% protection against severe rotavirus gastroenteritis caused by G1 and non-G1 serotypes in Latin American and European clinical trials; and of public health importance, Rotarix reduced hospitalizations of all-cause gastroenteritis by 40 and 75%, respectively. Efficacy against G2P[4] strains ranged from 41% in Latin America to 81% in Europe. In the former, Rotarix afforded sustained high protection (80.5%; 95% CI: 71.3-87.1) against severe rotavirus gastroenteritis during the first 2 years of life in a region with a changing pattern of wild-type rotavirus circulation. In a recently completed vaccine trial in South Africa and Malawi, Rotarix showed an overall efficacy of 61.2% (95% CI: 44.0-73.2) by 1 year of age. Although these rates are lower than those from developed and middle-income countries, they look promising given the lack of other effective interventions. With the expanding introduction of rotavirus vaccines into national immunization programs, postmarketing surveillance should be conducted to measure the impact of rotavirus vaccination, as well as continued monitoring of circulating rotavirus strains.

Effect of rotavirus vaccination on death from childhood diarrhea in Mexico

BACKGROUND

A phased introduction of a monovalent rotavirus vaccine occurred in Mexico from February 2006 through May 2007. We assessed the effect of vaccination on deaths from diarrhea in Mexican children in 2008 and 2009.

METHODS

We obtained data on deaths from diarrhea, regardless of cause, from January 2003 through May 2009 in Mexican children under 5 years of age. We compared diarrhea-related mortality in 2008 and during the 2008 and 2009 rotavirus seasons with the mortality at baseline (2003-2006), before the introduction of the rotavirus vaccine. Vaccine coverage was estimated from administrative data.

RESULTS

By December 2007, an estimated 74% of children who were 11 months of age or younger had received one dose of rotavirus vaccine. In 2008, there were 1118 diarrhea-related deaths among children younger than 5 years of age, a reduction of 675 from the annual median of 1793 deaths during the 2003-2006 period. Diarrhea-related mortality fell from an annual median of 18.1 deaths per 100,000 children at baseline to 11.8 per 100,000 children in 2008 (rate reduction, 35%; 95% confidence interval [CI], 29 to 39; P<0.001). Among infants who were 11 months of age or younger, diarrhea-related mortality fell from 61.5 deaths per 100,000 children at baseline to 36.0 per 100,000 children in 2008 (rate reduction, 41%; 95% CI, 36 to 47; P<0.001). As compared with baseline, diarrhea-related mortality was 29% lower for children between the ages of 12 and 23 months, few of whom were age-eligible for vaccination. Mortality among unvaccinated children between the ages of 24 and 59 months was not significantly reduced. The reduction in the number of diarrhea-related deaths persisted through two full rotavirus seasons (2008 and 2009).

CONCLUSIONS

After the introduction of a rotavirus vaccine, a significant decline in diarrhea-related deaths among Mexican children was observed, suggesting a potential benefit from rotavirus vaccination.

Effect of human rotavirus vaccine on severe diarrhea in African infants

BACKGROUND

Rotavirus is the most common cause of severe gastroenteritis among young children worldwide. Data are needed to assess the efficacy of the rotavirus vaccine in African children.

METHODS

We conducted a randomized, placebo-controlled, multicenter trial in South Africa (3166 infants; 64.1% of the total) and Malawi (1773 infants; 35.9% of the total) to evaluate the efficacy of a live, oral rotavirus vaccine in preventing severe rotavirus gastroenteritis. Healthy infants were randomly assigned in a 1:1:1 ratio to receive two doses of vaccine (in addition to one dose of placebo) or three doses of vaccine--the pooled vaccine group--or three doses of placebo at 6, 10, and 14 weeks of age. Episodes of gastroenteritis caused by wild-type rotavirus during the first year of life were assessed through active follow-up surveillance and were graded with the use of the Vesikari scale.

RESULTS

A total of 4939 infants were enrolled and randomly assigned to one of the three groups; 1647 infants received two doses of the vaccine, 1651 infants received three doses of the vaccine, and 1641 received placebo. Of the 4417 infants included in the per-protocol efficacy analysis, severe rotavirus gastroenteritis occurred in 4.9% of the infants in the placebo group and in 1.9% of those in the pooled vaccine group (vaccine efficacy, 61.2%; 95% confidence interval, 44.0 to 73.2). Vaccine efficacy was lower in Malawi than in South Africa (49.4% vs. 76.9%); however, the number of episodes of severe rotavirus gastroenteritis that were prevented was greater in Malawi than in South Africa (6.7 vs. 4.2 cases prevented per 100 infants vaccinated per year). Efficacy against all-cause severe gastroenteritis was 30.2%. At least one serious adverse event was reported in 9.7% of the infants in the pooled vaccine group and in 11.5% of the infants in the placebo group.

CONCLUSIONS

Human rotavirus vaccine significantly reduced the incidence of severe rotavirus gastroenteritis among African infants during the first year of life. (ClinicalTrials.gov number, NCT00241644.)

Is it cost-effective to introduce rotavirus vaccination in the Dutch national immunization program?

This study assessed whether the inclusion of two rotavirus (RV) vaccines in the Dutch national immunization programme is cost-effective. Costs and outcomes in unvaccinated and vaccinated populations are compared for a time period of 20 years. In the baseline, assuming competitive market forces in relation to vaccine costs, Rotarix is more cost-effective than RotaTeq, resulting in a cost-utility ratio (CUR) of euro 53,000 per DALY (third payer perspective) and euro 49,000 per DALY (societal perspective), but both considered as being not cost-effective. Vaccine-related costs, annual epidemic-size, and indirect protection are the major factors that determine cost-effectiveness of RV vaccination.

Efficacy of the pentavalent rotavirus vaccine, RotaTeq®, in Finnish infants up to 3 years of age: the Finnish Extension Study

Rotavirus Efficacy and Safety Trial (REST) enrolled nearly 70,000 infants, of whom more than 23,000 were from Finland. REST determined the efficacy of the pentavalent rotavirus vaccine (RV5) against rotavirus-related hospitalisations and emergency department (ED) visits in the first year after vaccination. Finnish infants initially in REST transitioned into the Finnish Extension Study (FES), where they were followed for rotavirus-related hospitalisations and ED visits through their second year of life and beyond. FES identified 150 (31%) additional rotavirus gastroenteritis (RVGE) cases beyond those identified in REST in the Finnish participants. Overall, RV5 reduced RVGE hospitalisations and ED visits, regardless of the rotavirus serotype, by 93.8% (95% confidence interval [CI]: 90.8-95.9%) for up to 3.1 years following the last vaccine dose. Vaccine efficacy against combined hospitalisations and ED visits between ages 4 months to 11 months, 12 months to 23 months, and 24 months to 35 months was 93.9% (95% CI: 89.1-96.9%), 94.4% (95% CI: 90.2-97.0%), and 85.9% (95% CI: 51.6-97.2%), respectively. The reduction of hospitalisations and ED visits due to any acute gastroenteritis, rotavirus or not, was 62.4% (95% CI: 57.6-66.6%) over the entire follow-up period. The results from FES confirm that RV5 induces high and sustained protection against rotavirus-related hospitalisations and ED visits, and has a very substantial impact on all gastroenteritis-related hospitalisations and ED visits into the third year of life in Finnish children.

Rotaviruses: from basic research to disease prevention by vaccination

The third European Rotavirus Biology Meeting, very ably organized by J Gray and M Iturriza-Gómara (Health Protection Agency, London, UK), took place at Cameron House in the picturesque environment of Loch Lomond, with beautiful and warm weather supporting the event. A total of 62 scientists, mainly from Europe but also from India and the USA, participated. The social program included a guided tour of the Glengoyne Distillery (north of Glasgow), who have produced Scotch whisky for almost 200 years, and a Scottish-themed dinner with ‘celebration of the haggis’, performances by two Highland dancers and subsequent ceilidh dancing. The scientific program covered various aspects of rotavirus biology, molecular epidemiology and vaccine development.

A mathematical model of the indirect effects of rotavirus vaccination

Rotavirus (RV) infections progressively confer natural immunity against subsequent infection. Similarly to natural infection, vaccination with a live attenuated vaccine potentially reduces RV transmission and induces herd protection. A mathematical transmission model was developed to project the impact of a vaccination programme on the incidence of RV infection and disease for five countries in the European Union. With vaccination coverage rates of 70%, 90% and 95% the model predicted that, in addition to the direct effect of vaccination, herd protection induced a reduction in RV-related gastroenteritis (GE) incidence of 25%, 22% and 20%, respectively, for RV-GE of any severity, and of 19%, 15%, and 13%, respectively, for moderate-to-severe RV-GE, 5 years after implementation of a vaccination programme.

A critical review on a globally-licensed, live, orally-administrable, monovalent human rotavirus vaccine: Rotarix

Rotavirus is the major cause of severe gastroenteritis in children worldwide, and two, live, orally-administrable vaccines are licensed globally. They are Rotarix, a monovalent, human rotavirus-based vaccine (GlaxoSmithKline), and RotaTeq, a pentavalent, bovine-human reassortant vaccine (Merck). The RIX4414 strain, a G1P[8] virus, is contained in the Rotarix vaccine. It grows efficiently in the human intestine, as evidenced by vaccine virus shedding into faeces. Efficient multiplication of RIX4414 in the intestines may play a role in stimulating immune effectors other than neutralizing antibodies that may explain the protective immunity against fully heterotypic G2P[4] strains. The protective efficacy against severe rotavirus gastroenteritis afforded by Rotarix is consistently better against strains that share with RIX4414 both G and P serotypes (i.e., G1P[8]), or only P serotype (i.e., G3P[8], G4P[8] and G9P[8]). The Rotarix vaccine is safe regarding intussusception if its first dose is administered between 6 and 12 weeks of age and the last dose by 24 weeks of age with a minimum interval of 4 weeks between the two doses. The expansion by Advisory Committee on Immunization Practices, USA, of the age limit for the first dose to age <15 weeks, and the last dose by 8 months requires close monitoring.

Estimating average inpatient and outpatient costs and childhood pneumonia and diarrhoea treatment costs in an urban health centre in Zambia

Background

Millions of children die every year in developing countries, from preventable diseases such as pneumonia and diarrhoea, owing to low levels of investment in child health. Investment efforts are hampered by a general lack of adequate information that is necessary for priority setting in this sector. This paper measures the health system costs of providing inpatient and outpatient services, and also the costs associated with treating pneumonia and diarrhoea in under-five children at a health centre in Zambia.

Methods

Annual economic and financial cost data were collected in 2005-2006. Data were summarized in a Microsoft excel spreadsheet to obtain total department costs and average disease treatment costs.

Results

The total annual cost of operating the health centre was US$1,731,661 of which US$1 284 306 and US$447,355 were patient care and overhead departments costs, respectively. The average cost of providing out-patient services was US$3 per visit, while the cost of in-patient treatment was US$18 per bed day. The cost of providing dental services was highest at US$20 per visit, and the cost of VCT services was lowest, with US$1 per visit. The cost per out-patient visit for under-five pneumonia was US$48, while the cost per bed day was US$215. The cost per outpatient visit attributed to under-five diarrhoea was US$26, and the cost per bed day was US$78.

Conclusion

In the face of insufficient data, a cost analysis exercise is a difficult but feasible undertaking. The study findings are useful and applicable in similar settings, and can be used in cost effectiveness analyses of health interventions.

Effect of prophylactic paracetamol administration at time of vaccination on febrile reactions and antibody responses in children: two open-label, randomised controlled trials

BACKGROUND

Although fever is part of the normal inflammatory process after immunisation, prophylactic antipyretic drugs are sometimes recommended to allay concerns of high fever and febrile convulsion. We assessed the effect of prophylactic administration of paracetamol at vaccination on infant febrile reaction rates and vaccine responses.

METHODS

In two consecutive (primary and booster) randomised, controlled, open-label vaccination studies, 459 healthy infants were enrolled from ten centres in the Czech Republic. Infants were randomly assigned with a computer-generated randomisation list to receive three prophylactic paracetamol doses every 6-8 h in the first 24 h (n=226) or no prophylactic paracetamol (n=233) after each vaccination with a ten-valent pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) co-administered with the hexavalent diphtheria-tetanus-3-component acellular pertussis-hepatitis B-inactivated poliovirus types 1, 2, and 3-H influenzae type b (DTPa-HBV-IPV/Hib) and oral human rotavirus vaccines. The primary objective in both studies was the reduction in febrile reactions of 38.0 degrees C or greater in the total vaccinated cohort. The second objective was assessment of immunogenicity in the according-to-protocol cohort. These studies are registered with ClinicalTrials.gov, numbers NCT00370318 and NCT00496015.

FINDINGS

Fever greater than 39.5 degrees C was uncommon in both groups (after primary: one of 226 participants [<1%] in prophylactic paracetamol group vs three of 233 [1%] in no prophylactic paracetamol group; after booster: three of 178 [2%] vs two of 172 [1%]). The percentage of children with temperature of 38 degrees C or greater after at least one dose was significantly lower in the prophylactic paracetamol group (94/226 [42%] after primary vaccination and 64/178 [36%] after booster vaccination) than in the no prophylactic paracetamol group (154/233 [66%] after primary vaccination and 100/172 [58%] after booster vaccination). Antibody geometric mean concentrations (GMCs) were significantly lower in the prophylactic paracetamol group than in the no prophylactic paracetamol group after primary vaccination for all ten pneumococcal vaccine serotypes, protein D, antipolyribosyl-ribitol phosphate, antidiphtheria, antitetanus, and antipertactin. After boosting, lower antibody GMCs persisted in the prophylactic paracetamol group for antitetanus, protein D, and all pneumococcal serotypes apart from 19F.

INTERPRETATION

Although febrile reactions significantly decreased, prophylactic administration of antipyretic drugs at the time of vaccination should not be routinely recommended since antibody responses to several vaccine antigens were reduced.

FUNDING

GlaxoSmithKline Biologicals (Belgium).

Public health impact and cost effectiveness of mass vaccination with live attenuated human rotavirus vaccine (RIX4414) in India: model based analysis

OBJECTIVES

To examine the public health impact of mass vaccination with live attenuated human rotavirus vaccine (RIX4414) in a birth cohort in India, and to estimate the cost effectiveness and affordability of such a programme.

DESIGN

Decision analytical Markov model encompassing all direct medical costs. Infection risk and severity depended on age, number of previous infections, and vaccination history; probabilities of use of inpatient and outpatient health services depended on symptom severity.

DATA SOURCES

Published clinical, epidemiological, and economic data. When possible, parameter estimates were based on data specific for India. Population Simulated Indian birth cohort followed for five years.

MAIN OUTCOME MEASURES

Decrease in rotavirus gastroenteritis episodes (non-severe and severe), deaths, outpatient visits, and admission to hospital; incremental cost effectiveness ratio of vaccination expressed as net cost in 2007 rupees per life year saved.

RESULTS

In the base case, vaccination prevented 28,943 (29.7%) symptomatic episodes, 6981 (38.2%) severe episodes, 164 deaths (41.0%), 7178 (33.3%) outpatient visits, and 812 (34.3%) admissions to hospital per 100,000 children. Vaccination cost 8023 rupees (about pound100, euro113, $165) per life year saved, less than India's per capita gross domestic product, a common criterion for cost effectiveness. The net programme cost would be equivalent to 11.6% of the 2006-7 budget of the Indian Department of Health and Family Welfare. Model results were most sensitive to variations in access to outpatient care for those with severe symptoms. If this parameter was increased to its upper limit, the incremental cost effectiveness ratio for vaccination still fell between one and three times the per capita gross domestic product, meeting the World Health Organization's criterion for "cost effective" interventions. Uncertainty analysis indicated a 94.7% probability that vaccination would be cost effective according to a criterion of one times per capita gross domestic product per life year saved, and a 97.8% probability that it would be cost effective according to a criterion of three times per capita gross domestic product.

CONCLUSIONS

Across a wide range of assumptions, mass RIX4414 vaccination in India would probably prevent substantial morbidity and mortality at a cost per life year saved below typical thresholds of cost effectiveness. The opportunity costs of such a programme in this or similar settings, however, should be weighed up carefully.

Licensed Vaccines for Rotavirus Prevention in the US: A Review

Objective:

To review the pharmacology, efficacy, safety, and tolerability of RotaTeq and RotaRix, 2 rotavirus vaccines.

Data Sources:

English-language articles were obtained via MEDLINE (1966-August 2009) and EMBASE (1980-August 2009) searches using the key words rotavirus vaccine, epidemiology, diarrhea, intussusception, RotaShield, RotaTeq, and RotaRix. Bibliographies of selected articles were used to identify additional sources.

Study Selection and Data Extraction:

Available published articles reporting the results of human studies of rotavirus vaccines were reviewed for inclusion in this article. Additional information regarding clinical trials and adverse events was obtained from the manufacturer's prescribing information for each vaccine.

Data Synthesis:

RotaTeq is a live, attenuated human-bovine pentavalent vaccine, and RotaRix is a live, attenuated human vaccine. Both vaccines are approved for the prevention of rotavirus infection and recommended for routine immunization in healthy infants aged 14 weeks to 8 months. The vaccines differ in virologic characteristics, but clinical trials indicate similar efficacy and safety. Each vaccine is more than 70% effective in preventing any severity of rotavirus gastroenteritis and more than 98% effective in preventing severe disease through one full season of rotavirus exposure postvaccination. Efficacy begins to wane during the second season of rotavirus exposure. Post hoc analyses of clinical trials indicated an 85–100% reduction in hospitalizations and emergency department visits following vaccination. Both vaccines have been well tolerated. Fever, vomiting, and diarrhea are the most reported adverse events. Intussusception and Kawasaki syndrome have been reported, but occurrence of these events has not been shown to be significant in comparison with the background rate for each adverse event.

Conclusions:

RotaTeq and RotaRix are effective for the prevention of rotavirus infection in the US, Europe, and Latin America. Additional studies are needed to assess their duration of protection, worldwide efficacy, effect on the reduction of healthcare resource utilization, and adverse event monitoring.