Prevention of rotavirus disease: guidelines for use of rotavirus vaccine. American Academy of Pediatrics

Safety monitoring of ROTAVAC vaccine and etiological investigation of intussusception in India: study protocol

Background

ROTAVAC, an indigenous rotavirus vaccine, was introduced in the universal immunization program of India in four states in 2016 and expanded to five more states in 2017. The clinical trial on efficacy of ROTAVAC did not detect an increased risk of intussusception, but the trial was not large enough to detect a small risk. This protocol paper describes the establishment and implementation of a surveillance system to monitor the safety of rotavirus vaccine and investigate the potential infectious etiologies of intussusception.

Methods

This is a multi-centric hospital-based active surveillance being conducted at 28 hospitals in nine states of India. Data gathered from surveillance will be used to assess the risk of intussusception after ROTAVAC administration and to determine the infectious etiologies of intussusception. For safety assessment of ROTAVAC vaccine, children aged less than two years with intussusception admitted at the sentinel hospitals are enrolled into surveillance, a case report form completed, and a copy of the vaccination card obtained. The risk of intussusception following rotavirus vaccination will be assessed using a self-controlled case-series design. The investigation for potential infectious etiologies of intussusception is through a matched case-control design. Children enrolled for the safety assessment serve as cases and for each case, an age, gender and location matched control is enrolled within 30 days of case enrollment. Stool specimens are obtained from cases and controls. All forms and specimens are sent to the referral laboratory for data entry, analysis, multiplexed molecular testing, and storage.

Discussion

Anticipated public health benefits of this surveillance include the generation of information useful to national government on safety of vaccine and to make future decisions on vaccine use through risk-benefit analysis. Investigating infectious agents may help to determine the potential infectious etiologies of intussusception.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5809-7) contains supplementary material, which is available to authorized users.

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.

Vaccinations in children on immunosuppressive medications for renal disease

Renal diseases are often treated with immunosuppressive medications, placing patients at risk of infections, some of which are vaccine-preventable. However, in such patients vaccinations may be delayed or disregarded due to complications of the underlying disease process and challenges in its management. The decision to administer vaccines to immunosuppressed children is a risk-benefit balance as such children may have a qualitatively diminished immunological response or develop diseases caused by the vaccine pathogen. Vaccination may cause a flare-up of disease activity or provocation of graft rejection in renal transplant recipients. Moreover, it cannot be assumed that a given antibody level provides the same protection in immunosupressed children as in healthy ones. We have evaluated the safety and efficacy of licensed vaccines in children on immunosuppressive therapy and in renal transplant recipients. The limited evidence available suggests that vaccines are most effective if given early, ideally before the requirement for immunosuppressive therapy, which may require administration of accelerated vaccine courses. Once treatment with immunosuppressive drugs is started, inactivated vaccines are usually considered to be safe when the disease is quiescent, but supplemental doses may be required. In the majority of cases, live vaccines are to be avoided. All vaccines are generally contraindicated within 3-6 months of a renal transplant.

Lessons Learned From Making and Implementing Vaccine Recommendations in the U.S

After publication of certain vaccine recommendations made by the Advisory Committee on Immunization Practices, several unexpected events have occurred during implementation of these recommendations. These have included changes in recommendations following adverse events involved with a particular vaccine and the conferral of community protection as an offshoot of vaccination of a specific population. Vaccine shortages and hesitancy have also been proven impediments to full implementation, and vaccine recommendations have not gone unaffected by either public perception of a vaccine or by cost considerations.

The dichotomy of pathogens and allergens in vaccination approaches

Traditional prophylactic vaccination to prevent illness is the primary objective of many research activities worldwide. The golden age of vaccination began with an approach called variolation in ancient China and the evolution of vaccines still continues today with modern developments such as the production of Gardasil(TM) against HPV and cervical cancer. The historical aspect of how different forms of vaccination have changed the face of medicine and communities is important as it dictates our future approaches on both a local and global scale. From the eradication of smallpox to the use of an experimental vaccine to save a species, this review will explore these successes in infectious disease vaccination and also discuss a few significant failures which have hampered our efforts to eradicate certain diseases. The second part of the review will explore designing a prophylactic vaccine for the growing global health concern that is allergy. Allergies are an emerging global health burden. Of particular concern is the rise of food allergies in developed countries where 1 in 10 children is currently affected. The formation of an allergic response results from the recognition of a foreign component by our immune system that is usually encountered on a regular basis. This may be a dust-mite or a prawn but this inappropriate immune response can result in a life-time of food avoidance and lifestyle restrictions. These foreign components are very similar to antigens derived from infectious pathogens. The question arises: should the allergy community be focussing on protective measures rather than ongoing therapeutic interventions to deal with these chronic inflammatory conditions? We will explore the difficulties and benefits of prophylactic vaccination against various allergens by means of genetic technology that will dictate how vaccination against allergens could be utilized in the near future.

A critical time for rotavirus vaccines: a review

Universal introduction of rotavirus vaccines into childhood immunization programs is expected to substantially reduce the mortality from rotavirus gastroenteritis in developing countries (currently estimated at 702,000 annual deaths among children less than 5 years of age). In addition, it is expected to virtually eliminate hospitalizations due to rotavirus gastroenteritis in developed countries. Two rotavirus vaccines, Rotarix (GlaxoSmithKline Biologicals, Belgium) and RotaTeq (Merck & Co., USA) have recently completed Phase III clinical trials, each involving more than 60,000 children. Both vaccines appear safe with respect to intussusception, and are highly efficacious in preventing severe gastroenteritis due to rotavirus strains carrying predominantly serotype G1. The monovalent human rotavirus vaccine Rotarix, possessing serotype P1A[8],G1, is being first introduced into developing countries, whereas the pentavalent bovine-human reassortant rotavirus vaccine RotaTeq, comprising G-types G1, G2, G3, G4 and P-type P1A[8], will be initially introduced into the USA and Europe. Current disease burden estimates and economic justification will be required wherever the vaccines are introduced. Confirmation of the safety of both vaccines will require extensive postlicensure evaluation in which it will be key to assure adherence to administration of the first dose of either vaccine before 3 months of age. Assessment of the ability of each vaccine to provide protection against an increasingly diverse population of rotavirus strains will crucially depend on continuous global strain surveillance. Finally, efforts to improve existing rotavirus vaccines and to develop alternative vaccines should continue, so as to ensure that the prerotavirus vaccine era is consigned to a historical context.

Vaccine Safety Surveillance Systems: Critical Elements and Lessons Learned in the Development of the US Vaccine Safety Datalink's Rapid Cycle Analysis Capabilities

Since the late 1990s, there have been tremendous strides made in improving the capacity for carrying out routine active surveillance of new vaccines in the United States. These strides have led to new surveillance systems that are now in place. Some of the critical elements that are part of successful vaccine or drug safety surveillance systems include their use of (i) longitudinal data from a discrete enumerated population base, (ii) frequent, routine transfers of small amounts of data that are easy to collect and collate, (iii) avoidance of mission creep, (iv) statistical capabilities, (v) creation of an “industrialized process” approach and (vi) political safe harbor.

Vaccines for preventing rotavirus diarrhoea: vaccines in use

BACKGROUND

Rotavirus results in more diarrhoea-related deaths in children less than five years of age than any other single agent in countries with high childhood mortality. It is also a common cause of diarrhoea-related hospital admissions in countries with low childhood mortality. Currently licensed rotavirus vaccines include a monovalent rotavirus vaccine (RV1; Rotarix, GlaxoSmithKline Biologicals) and a pentavalent rotavirus vaccine (RV5; RotaTeq, Merck & Co., Inc.). Lanzhou lamb rotavirus vaccine (LLR; Lanzhou Institute of Biomedical Products) is used in China only.

OBJECTIVES

To evaluate rotavirus vaccines approved for use (RV1, RV5, and LLR) for preventing rotavirus diarrhoea.

SEARCH METHODS

We searched MEDLINE (via PubMed) (1966 to May 2012), the Cochrane Infectious Diseases Group Specialized Register (10 May 2012), CENTRAL (published in The Cochrane Library 2012, Issue 5), EMBASE (1974 to 10 May 2012), LILACS (1982 to 10 May 2012), and BIOSIS (1926 to 10 May 2012). We also searched the ICTRP (10 May 2012), www.ClinicalTrials.gov (28 May 2012) and checked reference lists of identified studies.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) in children comparing rotavirus vaccines approved for use with placebo, no intervention, or another vaccine.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility, extracted data, and assessed risk of bias. We combined dichotomous data using the risk ratio (RR) and 95% confidence intervals (CI). We stratified the analysis by child mortality, and used GRADE to evaluate evidence quality.

MAIN RESULTS

Forty-one trials met the inclusion criteria and enrolled a total of 186,263 participants. Twenty-nine trials (101,671 participants) assessed RV1, and 12 trials (84,592 participants) evaluated RV5. We did not find any trials assessing LLR.RV1Children aged less than one year: In countries with low-mortality rates, RV1 prevents 86% of severe rotavirus diarrhoea cases (RR 0.14, 95% CI 0.07 to 0.26; 40,631 participants, six trials; high-quality evidence), and, based on one large multicentre trial in Latin America and Finland, probably prevents 40% of severe all-cause diarrhoea episodes (rate ratio 0.60, 95% CI 0.50 to 0.72; 17,867 participants, one trial; moderate-quality evidence). In countries with high-mortality rates, RV1 probably prevents 63% of severe rotavirus diarrhoea cases (RR 0.37, 95% CI 0.18 to 0.75; 5414 participants, two trials; moderate-quality evidence), and, based on one trial in Malawi and South Africa, 34% of severe all-cause diarrhoea cases (RR 0.66, 95% CI 0.44 to 0.98; 4939 participants, one trial; moderate-quality evidence).Children aged up to two years: In countries with low-mortality rates, RV1 prevents 85% of severe rotavirus diarrhoea cases (RR 0.15, 95% CI 0.12 to 0.20; 32,854 participants, eight trials; high-quality evidence), and probably 37% of severe all-cause diarrhoea episodes (rate ratio 0.63, 95% CI 0.56 to 0.71; 39,091 participants, two trials; moderate-quality evidence). In countries with high-mortality rates, based on one trial in Malawi and South Africa, RV1 probably prevents 42% of severe rotavirus diarrhoea cases (RR 0.58, 95% CI 0.42 to 0.79; 2764 participants, one trial; moderate-quality evidence), and 18% of severe all-cause diarrhoea cases (RR 0.82, 95% CI 0.71 to 0.95; 2764 participants, one trial; moderate-quality evidence).RV5Children aged less than one year: In countries with low-mortality rates, RV5 probably prevents 87% of severe rotavirus diarrhoea cases (RR 0.13, 95% CI 0.04 to 0.45; 2344 participants, three trials; moderate-quality evidence), and, based on one trial in Finland, may prevent 72% of severe all-cause diarrhoea cases (RR 0.28, 95% CI 0.16 to 0.48; 1029 participants, one trial; low-quality evidence). In countries with high-mortality rates, RV5 prevents 57% of severe rotavirus diarrhoea (RR 0.43, 95% CI 0.29 to 0.62; 5916 participants, two trials; high-quality evidence), but there was insufficient data to assess the effect on severe all-cause diarrhoea.Children aged up to two years: Four studies provided data for severe rotavirus and all-cause diarrhoea in countries with low-mortality rates. Three trials reported on severe rotavirus diarrhoea cases and found that RV5 probably prevents 82% (RR 0.18, 95% CI 0.07 to 0.50; 3190 participants, three trials; moderate-quality evidence), and another trial in Finland reported on severe all-cause diarrhoea cases and found that RV5 may prevent 96% (RR 0.04, 95% CI 0.00 to 0.70; 1029 participants, one trial; low-quality evidence). In high-mortality countries, RV5 prevents 41% of severe rotavirus diarrhoea cases (RR 0.59, 95% CI 0.43 to 0.82; 5885 participants, two trials; high-quality evidence), and 15% of severe all-cause diarrhoea cases (RR 0.85, 95% CI 0.75 to 0.98; 5977 participants, two trials; high-quality evidence).There was no evidence of a vaccine effect on mortality (181,009 participants, 34 trials; low-quality evidence), although the trials were not powered to detect an effect on this end point.Serious adverse events were reported in 4565 out of 99,438 children vaccinated with RV1 and in 1884 out of 78,226 children vaccinated with RV5. Fifty-eight cases of intussusception were reported in 97,246 children after RV1 vaccination, and 34 cases in 81,459 children after RV5 vaccination. No significant difference was found between children receiving RV1 or RV5 and placebo in the number of serious adverse events, and intussusception in particular.

AUTHORS' CONCLUSIONS

RV1 and RV5 prevent episodes of rotavirus diarrhoea. The vaccine efficacy is lower in high-mortality countries; however, due to the higher burden of disease, the absolute benefit is higher in these settings. No increased risk of serious adverse events including intussusception was detected, but post-introduction surveillance studies are required to detect rare events associated with vaccination.

Vaccines for preventing rotavirus diarrhoea: vaccines in use

BACKGROUND

Rotavirus results in more diarrhoea-related deaths in children less than five years of age than any other single agent in low- and middle-income countries. It is also a common cause of diarrhoea-related hospital admissions in high-income countries. The World Health Organization (WHO) recommends that all children should be vaccinated with a monovalent rotavirus vaccine (RV1; Rotarix, GlaxoSmithKline Biologicals) or a pentavalent rotavirus vaccine (RV5; RotaTeq, Merck & Co., Inc.), with a stronger recommendation for countries where deaths due to diarrhoea comprise more than 10% of all deaths. Lanzhou lamb rotavirus vaccine (LLR; Lanzhou Institute of Biomedical Products) is used in China only.

OBJECTIVES

To evaluate rotavirus vaccines approved for use (RV1, RV5, and LLR) for preventing rotavirus diarrhoea. Secondary objectives were to evaluate the efficacy of rotavirus vaccines on all-cause diarrhoea, hospital admission, death, and safety profiles.

SEARCH METHODS

For this update, we searched MEDLINE (via PubMed) in October 2011, and in June 2011 we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (published in The Cochrane Library 2011, Issue 2), , EMBASE, LILACS, and BIOSIS. We also searched the ICTRP (28 June 2011) and checked reference lists of identified studies.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility, extracted data, and assessed risk of bias. They combined dichotomous data using the risk ratio (RR) and 95% confidence intervals (CI) and used GRADE to evaluate evidence quality, which was reflected as follows: high quality ("vaccine prevents..."); moderate quality ("vaccine probably prevents..."); or low quality ("vaccine may prevent...").

MAIN RESULTS

Forty-three trials, including nine new trials for this update, met the inclusion criteria and enrolled 190,551 participants. Thirty-one trials assessed RV1, and 12 trials evaluated RV5. We did not find any trials assessing LLR.In children aged less than one year, RV1, compared to placebo, probably prevents 70% of all cases of rotavirus diarrhoea (RR 0.30, 95% CI 0.18 to 0.50; seven trials, 12,130 participants; moderate-quality evidence), and 80% of severe rotavirus diarrhoea cases (RR 0.20, 95% CI 0.11 to 0.35; seven trials, 35,004 participants; moderate-quality evidence). Similarly, RV5 prevents 73% of all rotavirus diarrhoea cases (RR 0.27, 95% CI 0.22 to 0.33; four trials, 7614 participants; high-quality evidence), and 77% of severe rotavirus diarrhoea cases (RR 0.23, 95% CI 0.08 to 0.71; three trials, 6953 participants; high-quality evidence). Both vaccines prevent over 80% of rotavirus diarrhoea cases that require hospitalization. For all-cause diarrhoea, based on two multi-centred trials from South Africa, Malawi, and Europe, RV1 may reduce severe cases by 42% (RR 0.58, 95% CI 0.40 to 0.84; two trials, 8291 participants; low--quality evidence). Also, based on one trial from Finland, RV5 may reduce severe cases by 72% (RR 0.28, 95% CI 0.16 to 0.48; one trial, 1029 participants; low-quality evidence).During the second year of life, compared to placebo, RV1 probably prevents 70% of all cases of rotavirus diarrhoea of any severity (RR 0.30, 95% CI 0.21 to 0.43; six trials, 8041 participants; moderate-quality evidence), and 84% of severe rotavirus diarrhoea cases (RR 0.16, 95% CI 0.12 to 0.21; eight trials, 32,854 participants; moderate-quality evidence). RV5 prevents 49% of all rotavirus diarrhoea cases of any severity (RR 0.51, 95% CI 0.36 to 0.72; four trials, 9784 participants; high-quality evidence), and 56% of severe rotavirus diarrhoea cases (RR 0.44, 95% CI 0.22 to 0.88; four trials, 9783 participants; high-quality evidence). For all-cause diarrhoea, RV1 probably reduces severe cases by 51% (RR 0.49, 95% CI 0.40 to 0.60; two trials, 6269 participants; moderate-quality evidence), and RV5 showed no difference with placebo (three trials, 8533 participants).Reported serious adverse events (including intussusception) after vaccination were measured in 95,178 children for RV1 and 77,480 for RV5, with no difference between the vaccines.

AUTHORS' CONCLUSIONS

RV1 and RV5 vaccines are effective in preventing rotavirus diarrhoea. These data support the WHO's global vaccine recommendation. The potential for reduced vaccine efficacy in low-income countries needs to be investigated. No increased risk of intussusception was detected, but surveillance monitoring studies are probably advisable in countries introducing the vaccine nationally.

Estimating the rotavirus hospitalization disease burden and trends, using capture-recapture methods

BACKGROUND

Rotavirus surveillance is needed to provide estimates of disease burden and to evaluate the effect of vaccination programs. Our objective was to use capture-recapture methods to estimate rotavirus hospitalization rates and to examine trends over time.

METHODS

Children <3 years of age residing in Hamilton County, Ohio hospitalized with acute gastroenteritis, and laboratory-confirmed rotavirus between 1997 and 2008 were identified through 2 independent surveillance systems: an active system with prospective enrollment of children admitted with acute gastroenteritis and a passive system of children identified by rotavirus testing as part of their usual medical care. Capture-recapture methods compared cases from both systems to estimate the number of missed cases from either system. Using census data for Hamilton County, rates per 10,000 with 95% confidence intervals (CI) for rotavirus hospitalizations were estimated.

RESULTS

Overall, 486 cases were identified using active surveillance and 244 using passive surveillance, with 127 cases captured by both. Using capture-recapture methods, the overall rate in children <3 years old was 26.9/10,000; CI: 24.1, 30.6. Rates varied by year: highest in 1998 (48.1/10,000; CI: 32.4, 92.2) and lowest in 2008 (3.2/10,000; CI: 2.1, 6.1) after rotavirus vaccine introduction. Among children <5 years old, rates were highest in <3-month-old children (51.8/10,000; CI: 39.4, 75.1) and lowest in older age groups: 24 to 35 months (20.5/10,000; CI: 14.7, 30.3) and 36 to 59 months (4.1/10,000; CI: 2.9, 7.2). Rates from capture-recapture methods and adjusted active system were comparable.

CONCLUSIONS

Capture-recapture methods were a useful tool to estimate rotavirus disease burden and to monitor trends, especially in the era of rotavirus immunization.

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.

Age dependence of the risk of intussusception following [corrected] rhesus-human reassortant rotavirus tetravalent vaccine: is it beyond doubt?

The relation between the risk of intussusception and age at the time of receipt of the first dose of rhesus-human reassortant rotavirus tetravalent vaccine (RRV-TV) has been studied extensively on the basis of Centers for Disease Control and Prevention (CDC) matched case-control study data, using various statistical methods, including conditional logistic regression and quadratic smoothing splines. However, different conclusions have been reported in published analyses regarding the dependence of the risk of intussusception on age at first dose. The authors reanalyzed the CDC matched case-control data set using unrestricted and restricted quadratic smoothing spline methods for various exposure windows (i.e., intervals postvaccination). These analyses indicated that the use of different models may lead to different conclusions. The restricted quadratic smoothing spline with appropriately chosen knot locations showed a statistically significant increased risk of intussusception associated with RRV-TV for the exposure window 3-14 days after the first dose at an age as young as 49 days, the youngest age in the data set at which vaccine was administered; this implies an increased risk of intussusception associated with RRV-TV at all ages studied.

Real-time surveillance to assess risk of intussusception and other adverse events after pentavalent, bovine-derived rotavirus vaccine

BACKGROUND

A pentavalent, bovine-derived rotavirus vaccine (RotaTeq, Merck) was licensed in 2006 for use in infants. A previously licensed rotavirus vaccine was withdrawn due to elevated risk of intussusception. We prospectively evaluated the risk of intussusception and other pre-specified adverse events among RotaTeq recipients in the Vaccine Safety Datalink.

METHODS

The exposed population included children from age 4 to 48 weeks who received RotaTeq between May 2006 and May 2008. Adverse events over the subsequent 30 days were ascertained from inpatient, outpatient, and emergency department files; cases of intussusception were validated by medical record review. An adaptation of sequential probability ratio testing was employed to compare the cumulative number of observed and expected adverse events on a weekly basis, and a "signal" was generated if the log-likelihood ratio reached a predetermined threshold. This allowed near real-time monitoring to detect selected adverse events. The expected number of cases of intussusception was determined from historical rates in the VSD population.

RESULTS

There were 207,621 doses of RotaTeq administered to the study population; 42% were first doses. Five children had computerized diagnosis codes for intussusception, and 6.75 cases were expected based on historical rates (relative risk = 0.74). No elevation in risk was identified for intussusception or any other adverse event. Two of five children with suspected intussusception based on diagnosis codes met the case criteria after medical record review.

CONCLUSIONS

This study illustrates the feasibility of rapid vaccine safety assessment and provides additional evidence that RotaTeq is not associated with an increased risk of intussusception.

Will pediatricians adopt the new rotavirus vaccine?

OBJECTIVES

Our objective was to determine the following among US pediatricians: (1) perceptions regarding burden of rotavirus disease and need for a vaccine; (2) intentions for recommending a newly licensed rotavirus vaccine; (3) perceived barriers to implementation; and (4) factors associated with plans for vaccine adoption.

PATIENTS AND METHODS

A network of 431 pediatricians was recruited from a random sample of American Academy of Pediatrics' members. The network was designed to be representative of the American Academy of Pediatrics with respect to region of the country, practice type, and practice setting. During January and February 2006, physicians were surveyed by Internet or mail. The survey contained a paragraph summarizing results of the new rotavirus vaccine trial. Respondents were asked about intentions to use the vaccine and anticipated barriers.

RESULTS

The survey response rate was 71%. Of the respondents, 52% strongly agreed and 37% somewhat agreed with the need for a rotavirus vaccine. If recommended for routine use, 50% would strongly recommend and 34% would recommend but not strongly; 52% would begin to use within 6 months and 27% from 6 months to 1 year. The top 3 "definite" barriers to implementation included concerns about uniform coverage of vaccine by insurers, lack of adequate reimbursement, and parental reluctance because of withdrawal of previous rotavirus vaccine. In multivariate analysis, factors associated with very likely adoption of the vaccine included perception of a high burden of rotavirus disease and a high level of confidence in prelicensure studies of vaccine safety. The presence of physician concerns about safety of the new vaccine and the perception of parental concerns about vaccine safety in general were negatively associated with adoption.

CONCLUSIONS

The majority of pediatricians reported willingness to implement the new rotavirus vaccine, most within 6 months. Major barriers to optimal implementation included provider concerns about reimbursement issues and parental acceptance of the vaccine.

A case-control study to determine risk factors for hospitalization for rotavirus gastroenteritis in U.S. children

OBJECTIVE

The objective of this case-control study nested within a surveillance study conducted at 3 hospitals (Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Children's Hospital of New Orleans, New Orleans, LA; and Hasbro Children's Hospital, Providence, RI) was to identify risk factors for rotavirus gastroenteritis requiring hospitalization.

PATIENTS

Cases were children < or =59 months of age who were admitted with acute gastroenteritis (AGE) and found to have rotavirus infection. Controls were selected from a birth certificate registry (Cincinnati and Providence) or a registry of patients from a large practice consortium in 11 locations (New Orleans).

RESULTS

Three hundred forty-nine rotavirus-infected cases and 1242 control subjects were enrolled. Breast feeding was protective against hospitalization for rotavirus AGE for infants <6 months of age. (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-13.2). Low-birth-weight (<2500 g) infants had increased risk for hospitalization even beyond the first few months of life (OR, 2.8; 95% CI, 1.6-5.0). Children in child care were more likely to be hospitalized for rotavirus AGE than those cared for at home, particularly those > or =24 months of age (OR, 3.0; 95% CI, 1.8-5.3). Other characteristics associated with rotavirus AGE hospitalization were children <24 months of age covered by Medicaid or without insurance (OR, 2.1; 95% CI, 1.4-3.2) and having another child in the house <24 months of age (OR, 1.6; 95% CI, 1.1-2.3). The data suggest that maternal age <25 years (OR, 1.4; 95% CI, 1.0-2.0) and a mother with less than a high school education (OR, 1.5; 95% CI, 1.0-2.3) may also increase risk of rotavirus hospitalization.

CONCLUSION

There are socioeconomic and environmental factors and aspects of the child's medical and dietary history that identify children at risk for hospitalization with rotavirus AGE.

Rhesus rotavirus vaccine effectiveness and factors associated with receipt of vaccine

BACKGROUND

The rhesus rotavirus tetravalent vaccine (RotaShield) had an efficacy of 75%-100% in preventing severe rotavirus disease in prelicensure clinical trials. Before RotaShield's withdrawal because of reports of intussusception, there was an opportunity to evaluate the postlicensure effectiveness of the vaccine. The objective of this study was to determine the effectiveness of the RotaShield vaccine against rotavirus gastroenteritis requiring hospitalization and to evaluate factors associated with vaccine receipt.

METHODS

Rotavirus cases were identified through active hospital-based rotavirus surveillance at 3 children's hospitals in Cincinnati, New Orleans and Providence. Cases were selected if they had been eligible for vaccine during the 10-month period when vaccine was available. Controls were matched to cases by date and county or state of birth. Immunization records were obtained from cases and controls to document receipt of RotaShield. Vaccine effectiveness (VE) was calculated for 1, 2, and 3 doses of vaccine with 95% confidence intervals (CI).

RESULTS

For the 10-month period, 136 cases and 440 controls were enrolled. For 3 versus 0 doses of RotaShield, the VE was 100% (CI: 75%, 100%); for 2 versus 0 doses, the VE was 100% (CI: 62%, 100%), and for 1 versus 0 doses the VE was 89% (CI: 49%, 97%). RotaShield receipt was associated with white race, having more than 1 adult in the household, having insurance and having an older, more educated mother.

CONCLUSIONS

This postlicensure study of RotaShield effectiveness found the vaccine to be highly effective in preventing rotavirus disease requiring hospitalization.

The Epidemiology of Paediatric Intussusception in Singapore: 1997 to 2004

Introduction: The world’s first rotavirus vaccine, Rotashield® or RRV-TV, was registered in the US in 1998, but withdrawn within a year because of an observed association with intussusception (IS). Surveillance for IS has consequently become important in safety monitoring of new-generation rotavirus vaccines during development. Post-marketing surveillance is also important, and requires the availability of local baseline epidemiology data on IS. Materials and Methods: An eight-year study of IS in children under 2 years of age in Singapore was performed by retrospective review of admissions to KK Women’s and Children’s Hospital, the main paediatric hospital, from 1997 to 2001, followed by prospective surveillance of all hospitals from 2001 to 2004, using the case definition of the Brighton Collaboration Intussusception Working Group. Results: The average IS incidence was 60 per 100,000 in under-ones, and 32 per 100,000 in under-twos, with a downward trend between 1999 and 2004. Ninety-two per cent of subjects were aged below one year, with 51% aged 6 months to 11 months. The mean age at which IS occurred increased from 6.4 months to 12.5 months over the study period. The male-to-female ratio was 1.3:1. No trend in IS numbers was observed over different months of the year. Conclusion: IS in Singapore shows no seasonality, but has demonstrated a trend of decreasing incidence in recent years. While highest in the first year of life, the risk of IS is increasing in the second year of life. Males have a slightly higher risk. Key words: Adverse effects, Rotavirus vaccines

The Lyme vaccine: a cautionary tale

People living in endemic areas acquire Lyme disease from the bite of an infected tick. This infection, when diagnosed and treated early in its course, usually responds well to antibiotic therapy. A minority of patients develops more serious disease, particularly after a delay in diagnosis or therapy, and sometimes chronic neurological, cardiac, or rheumatological manifestations. In 1998, the FDA approved a new recombinant Lyme vaccine, LYMErix, which reduced new infections in vaccinated adults by nearly 80%. Just 3 years later, the manufacturer voluntarily withdrew its product from the market amidst media coverage, fears of vaccine side-effects, and declining sales. This paper reviews these events in detail and focuses on the public communication of risks and benefits of the Lyme vaccine and important lessons learned.

The new pentavalent rotavirus vaccine composed of bovine (strain WC3) -human rotavirus reassortants

BACKGROUND

Infantile gastroenteritis caused by human rotaviruses is a prevalent disease throughout the world, causing dehydration and hospitalization in all countries. In developing countries, it is associated with a high mortality. A licensed vaccine against rotavirus was withdrawn because of a causal association with intussusception. A new vaccine has been developed and is a candidate for licensure.

METHODS

To recount the early development and recent demonstration of the safety and efficacy of the new vaccine. A bovine rotavirus attenuated for humans was isolated and reassorted with human rotaviruses of serotypes G1-4 and P1 to create a pentavalent vaccine. Multiple placebo-controlled clinical trials, including one involving approximately 70,000 infants, were conducted in multiple developed countries.

RESULTS

The pentavalent vaccine was well tolerated by infants less than 8 months of age, and the incidence of intussusception was similar among vaccine and placebo recipients. More than 90% of infants had a significant rise in serum antirotavirus IgA titer after 3 doses. Efficacy of 95% against severe disease causing hospitalization or emergency care was demonstrated, and pentavalent vaccine prevented 74% of all rotavirus disease.

CONCLUSIONS

If widely used, pentavalent vaccine would control rotavirus disease in the United States and other developed countries and could also have a major effect in developing countries.

Intussusception after administration of the rhesus tetravalent rotavirus vaccine (Rotashield): the search for a pathogenic mechanism

OBJECTIVES

The rhesus tetravalent rotavirus vaccine (RRV) was withdrawn from the routine program for childhood immunization in the United States because of the rare and unexpected occurrence of intussusception in the 2-week period after administration of the first dose.

METHODS

To search for the pathogenesis of this association, we compared the pathology of surgical specimens from infants who had surgical reduction of their intussusceptions within 2 weeks of receiving the vaccine (case patients; n = 8) with the pathology of specimens from children who had surgery > 2 weeks after immunization (n = 6) or who had never been immunized (n = 26). Tissue was examined for evidence of the vaccine strain of rotavirus by reverse transcriptase-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemical staining.

RESULTS

RRV was identified by RT-PCR in tissue samples from 7 of the 8 case patients and in 2 of the 6 children who received the vaccine at a more distant time (29 and 58 days before surgery), but it was not identified in samples from any of the nonvaccinated children. No evidence of rotavirus tissue involvement was detected in any of the children by in situ hybridization or immunohistochemical staining. Pathologic evidence (for example, inclusion bodies, smudge cells) of adenovirus infection was present in 35% of the 37 specimens examined by routine staining and immunohistochemistry.

CONCLUSIONS

The fact that RRV was detected by RT-PCR but not by either of the other assays could be explained by RRV being present in the lumen of the gut but not in the tissues of appendix, ileum, or Peyer's patches. The Peyer's patches were not hyperplastic, and we could not establish the pathogenic mechanism for this association.

Intussusception among young children in Europe

Intussusception, a potentially lethal condition with poorly understood etiology, is the most common cause of acute intestinal obstruction in children younger than 5 years old. In some cases, the condition has been associated with administration of the first licensed rotavirus vaccine, the reassortant rhesus-human tetravalent rotavirus vaccine (RRV-TV; RotaShield). No such association has to date been reported from large phase III safety trials with new rotavirus vaccines. As 2 new, live-attenuated oral rotavirus vaccines are currently under review for approval by the European Union regulatory authorities, a review of the clinical, etiologic and epidemiologic aspects of intussusception in Europe is urgently needed. We conducted a review of Medline literature, published from 1995 onwards on intussusception in the World Health Organization's European Region. The results are compared with data from previous reviews and other regions. The classic triad of intussusception symptoms (abdominal pain, abdominal mass, bloody stools) was present in 29-33% of patients according to the medical literature reviewed. Conservative treatment (barium, air or saline enema) was the rule (81% of cases), and few complications were observed during treatment. Treatment outcome was generally favorable, with recurrence occurring in approximately 1 in 10 patients, and only 1 death reported. Structural lead points were seen in 3% of patients; no other reliable data on the etiology of intussusception were found. The incidence of acute intussusception in young children in Europe, according to 6 heterogeneous hospital-based studies, ranged from 0.66 to 2.24 per 1000 children in inpatient departments and from 0.75 to 1.00 per 1000 children in emergency departments. Peak incidences were found in children 3-9 months of age. There are still gaps in our knowledge of intussusception with respect to its etiology and especially by which mechanisms RRV-TV might have caused it to occur. Data from regions outside Europe showed that rotavirus infection and disease are not associated with intussusception. As new rotavirus vaccines become available for use in Europe, postlicensure surveillance for intussusception is indicated and may be instrumental in further understanding the epidemiology of this condition and in further assessing the safety of future vaccines.

Intussusception incidence relative to rotavirus vaccine use in Honolulu

Rotavirus vaccine was in use during the period August 1998 to October 1999. Epidemics of intussusception during this period were allegedly due to rotavirus vaccine, which prompted the vaccine to be withdrawn. Hawaii's geographic location between Asia and the mainland United States may subject it to infectious disease epidemic periods midway between occurrence in Asia and occurrence in the mainland United States. In contrast, immunization recommendations are temporally identical across all 50 states. The purpose of this study was to determine whether an epidemic of intussusception was experienced in Honolulu during the period of rotavirus vaccine use. This is a retrospective study of data obtained from inpatient and emergency department discharge diagnosis codes of intussusception for children up to 36 months of age. The incidence data were plotted by time periods to identify possible epidemic periods. The data are graphed. The arrows on the graphs indicate the period of time that rotavirus vaccine was in use. These graphs are most consistent with an increase in the cases of intussusception during the period July 2000 to December 2000, and a possible decline of intussusception during the rotavirus vaccine period. These incidence data are inconsistent with a temporal association between rotavirus vaccine and an epidemic of intussusception in Honolulu.

Rotavirus gastroenteritis

Rotavirus is the single most important cause of severe, dehydrating gastroenteritis in infants and young children worldwide. Rotavirus gastroenteritis is associated with high morbidity in developed countries and significant mortality in developing countries. Virtually all children are infected with rotavirus by 3 years of age. Fecal-oral transmission is the most likely route of virus spread. Group A serotype strains G1 through G4 account for more than 90% of rotavirus gastroenteritis in humans, with G1 being the predominant serotype. The virus preferentially infects the mature small-intestinal enterocytes. Rotavirus gastroenteritis is characterized by fever, vomiting, and diarrhea, with vomiting particularly prominent. Dehydration is a frequent complication because of the severity of the diarrhea and the associated vomiting. Rehydration and maintenance of proper fluid and electrolyte balance remain the mainstay of treatment. Hygienic measures have little effect on the reduction of rotavirus infection rates. The disease can be effectively controlled by universal rotavirus vaccination.

Intussusception and rotavirus vaccines

The association between the first oral rotavirus vaccine to be licensed in the U.S. (Rotashield) and intussusception has presented a major challenge to the effort to reduce the global burden related to rotavirus infection. Although the risk of developing intussusception following immunization with Rotashield is low, debate continues about the estimation of intussusception risk and the events surrounding the withdrawal of the vaccine. The experience with Rotashield has highlighted the wisdom of parallel clinical trials in developing and developed countries and the value of post-licensure surveillance for the detection of uncommon adverse events. This review retraces the steps leading up to the withdrawal of the Rotashield vaccine and reflects on how this experience has influenced the development of other rotavirus vaccines.

The VP6 protein of rotavirus interacts with a large fraction of human naive B cells via surface immunoglobulins

Immunity to human group A rotavirus (RV), a major cause of viral gastroenteritis in infants, involves B lymphocytes that provide RV-specific antibodies. Additionally, some arguments suggest that naive B cells could be implicated in the first steps of the immune response against RV. The aim of our study was to analyze the interaction of VP6 and VP7 RV capsid proteins with human B cells depending on the immune status of the individual, i.e., naive or RV experienced. For this purpose, a two-color virus-like particle flow cytometry assay was devised to evaluate the blood B-lymphocyte reactivity to VP6 and VP7 proteins from healthy RV-exposed adults, recently infected infants, and neonates at birth. Both VP6 and VP7 interactions with B cells were mediated by surface immunoglobulins and probably by their Fab portions. VP7-reactive B lymphocytes were mainly detected from RV-experienced patients and almost exclusively in the CD27-positive memory cell fraction. Conversely, VP6-reactive B lymphocytes were detected at similar and high frequencies in adult, infant, and neonate samples. In adult samples, VP6 reacted with about 2% of the CD27-negative (CD27(neg)) naive B cells. These results demonstrated that the VP6 RV protein interacted with a large fraction of naive B lymphocytes from both adults and neonates. We propose that naive B cell-VP6 interaction might influence the strength and quality of the acquired immune response and should be considered for elaborating RV vaccine strategies.

A comparison of the effects of oral inoculation with Rotashield and pentavalent reassortant rotavirus vaccine (WC3-PV) on suckling CB17scid mice

The effects of oral inoculation into infant CB17(scid) mice of two reassortant rotavirus vaccines were compared. The vaccines were Rotashield and WC3-PV, a mixture of five reassortants (G1, G2, G3, G4 and P1; pentavalent reassortant vaccine). Control mice were inoculated with a placebo. At 6 days post-inoculation (p.i.), 8 of 13 (62 %; P<0.005) Rotashield-inoculated mice developed hepatitis and/or bile-duct obstruction compared with none of 11 mice given WC3-PV and none of 14 given placebo. In the Rotashield-inoculated mice, only serotype G3 rhesus rotavirus (RRV) was isolated from multiple sites, including intestine, liver, pancreas, spleen, blood and mesenteric lymph nodes. Recovery of RRV from Rotashield-inoculated mice followed a biphasic pattern. The two peaks of RRV recovery appeared to coincide firstly with replication in the intestine during days 1-3 p.i., and secondly with virus infection of the liver from days 10 to 15 p.i. WC3 reassortants of four different serotypes were detected only at day 1 p.i. in the intestine, liver, pancreas and blood cells from three WC3-PV-inoculated mouse pups. However, WC3-PV did not produce any hepatopathology. Rotashield and WC3-PV appeared to exhibit different biological activity in infant CB17(scid) mouse pups.

Vaccines for rotavirus gastroenteritis universally needed for infants

Rotavirus causes severe and often lifethreatening illness. Universal application of a safe and protective vaccine is justified in both developed and developing nations. Two vaccine candidates, one monovalent (Rotarix) and one multivalent (Rotateq), appear to meet these requirements and are likely to be licensed in the United States in the next 2 or 3 years. Both vaccines exhibited similar safety characteristics. There is little doubt that Rotateq and Rotarix will be shown to be effective for routine protection of infants. Unfortunately, despite numerous clinical trials, the most common serotype (PlaGa) commonly has been encountered as a natural challenge. Therefore, it is not known whether either vaccine possesses advantages in different epidemiological situations. Continuing the analogy with influenza virus, it may be that optimum protection against different serotypes requires a vaccine that is precisely homologous in antigen composition. If so, Rotateq would provide protection against the most common serotype PlaG1 because in includes both Pla and G1 rotavirus reassortants. Further, it would be expected to provide superior protection against G2, G3, and G4 wild-type virus because it contains reassortants of those specificities. In the case of a natural challenge with a serotype that was not G1, G2, G3, or G4, a Rotateq preparation containing a WC3 reassortant expressing the new G serotype could be formulated readily. The monotypic Rotarix may provide ideal protection against the PlaG1 rotavirus because it is composed solely of the PlaG1 strain. It may also provide cross-protection against other rotavirus serotypes adequate to protect against severe and life-threatening disease. In such a case, its monotypic composition may also provide significant economic savings in manufacturing. The resolution of these questions may have to await extensive post-licensure experience with each vaccine. In the future, possible application of rotavirus vaccine for other situations also should be explored, including use in older children to limit nosocomial infection, use in geriatric populations, use in the immunocompromised host, and possibly use in parents and other adults in contact with infants with rotavirus. Both Rotarix and Rotateq likely are to be launched at prices beyond those affordable in the poorest and neediest less-developed countries. It is essential that there be vigorous pursuit of new technologies to manufacture these products at drastically reduced cost if their true lifesaving potential is to be achieved.

An analysis of rotavirus vaccine reports to the vaccine adverse event reporting system: more than intussusception alone?

BACKGROUND

The rhesus-human rotavirus reassortant-tetravalent vaccine (RRV-TV) was licensed on August, 31, 1998, and subsequently recommended for routine infant immunizations in the United States. After approximately 1 million doses had been administered, an increase in acute risk of intussusception in vaccinees led to the suspension of the use of RRV-TV and its withdrawal from the market. These postmarketing safety studies focused on a single adverse event (intussusception) and, to minimize the risk of a false-positive finding, accepted only cases that met a strict case definition. Safer rotavirus vaccines are needed to prevent the substantial global morbidity and mortality caused by rotavirus infections; their development and future use may benefit from a better understanding of the postmarketing safety profile of RRV-TV beyond intussusception.

OBJECTIVE

To characterize more completely the postmarketing surveillance safety profile of RRV-TV more completely by review and analysis of Vaccine Adverse Event Reporting System (VAERS) case reports to better understand 1) whether severe adverse events other than intussusception may have occurred after RRV-TV and 2) the likely scope of gastrointestinal illnesses, of which the previously identified, highly specific intussusception cases may account for just a fraction.

SETTING AND PARTICIPANTS

Infants vaccinated with RRV-TV and other vaccines in the United States and for whom a report was submitted to VAERS during September 1, 1998, to December 31, 1999.

METHODOLOGY

To detect adverse events of interest other than intussusception, we used proportional morbidity analysis to compare the adverse event profile of VAERS reports among infants who received routine vaccines including RRV-TV (after excluding confirmed and suspected intussusception reports) with infants who received identical vaccine combinations but without RRV-TV. Next, to better capture all described diagnoses, signs, and symptoms associated with the suspected adverse events, a set of new codes was developed and assigned to each VAERS report. All 448 nonfatal RRV-TV-associated reports (including intussusception) were recoded manually from the clinical description on the VAERS report and categorized into clinical groups to better describe a spectrum of reported illnesses after the vaccine. Each report was assigned to one of the following hierarchical and mutually exclusive clinical groups: 1) diagnosed intussusception; 2) suspected intussusception; 3) illness consistent with either gastroenteritis or intussusception; 4) gastroenteritis; 5) other gastrointestinal diagnoses (ie, not consistent with intussusception or rotavirus-like gastroenteritis); and 6) nongastrointestinal diagnoses.

RESULTS

Even after excluding intussusception cases, a higher proportion of RRV-TV reports than non-RRV-TV reports included fever and various gastrointestinal symptoms, most notably bloody stool but also vomiting, diarrhea, abdominal pain, gastroenteritis, abnormal stool, and dehydration. Distribution of RRV-TV reports by clinical groups was as follows: diagnosed intussusception (109 [24%], suspected intussusception (36 [8%]), and illness consistent with gastroenteritis or intussusception (33 [7%]), gastroenteritis (101 [22%]), other gastrointestinal diagnoses (10 [2%]), and nongastrointestinal outcomes (159 [35%]). The median time interval between vaccination and illness onset decreased incrementally among the first 4 clinical groups: from 7 days for diagnosed intussusceptions to 3 days for gastroenteritis.

CONCLUSIONS

Intussusception and gastroenteritis were the most commonly reported outcomes; however, a substantial number of reports indicate signs and symptoms consistent with either illness, possibly suggestive of a spectrum of gastrointestinal illness(es) related to RRV-TV. Although VAERS data have recognized limitations such as underreporting (that may differ by vaccine) and are nearly always insufficient to prove causality between a vaccine and an adverse event, this safety profile of RRV-TV may aid better understanding of the pathophysiology of intussusception as well as development of future safer rotavirus vaccines.

Intravenous rehydration for gastroenteritis: how long does it really take?

BACKGROUND

For treatment of mild to moderate dehydration arising from viral gastroenteritis, the American Academy of Pediatrics recommends oral rehydration therapy over a 4-hour period. However, oral rehydration therapy remains largely underused by emergency physicians. Studies suggest that a major barrier is a perception that the time requirement for oral rehydration therapy is too long relative to intravenous (IV) hydration.

OBJECTIVE

: To test the hypothesis that children who receive IV hydration for gastroenteritis spend significantly less than 4 hours in the emergency department (ED).

DESIGN/METHODS

A prospective case series involving a consecutive sample of 549 children treated with IV hydration for mild to moderate dehydration at an urban pediatric ED. Treatment time was defined as period elapsed between when a physician placed a patient in an ED room and when he/she discharged the patient. We excluded time spent in the waiting room before seeing a physician. Using a standardized procedure, we collected data in September/October 2000 (fall), November 2000 to January 2001 (winter), and April/May 2001 (spring). To provide a measure of average pass-through time at this ED, we also collected data on all patients treated during consecutive 7-day periods in the fall (n = 502), winter (n = 776), and spring (n = 653). We performed univariate analysis of continuous variables using t tests for independent samples.

RESULTS

549 subjects received IV treatment for dehydration; of whom 55% were female, and mean age was 9.7 years. Treatment time for patients undergoing IV hydration exceeded 4 hours (mean = 5.4 +/- 2.4 hours; median = 5.0 hours). Mean time for IV treatment of dehydration was significantly longer than the mean time for treating other patients (5.4 vs. 1.2 hours, P < 0.001). Mean IV treatment times were: fall (5.1 hours), winter (5.5 hours), and spring (4.7 hours). Mean treatment time exceeded 4 hours regardless of time of day, day of the week, or age of child.

CONCLUSIONS

Contrary to our hypothesis, mean treatment time for IV therapy for mild to moderate dehydration exceeded the 4-hour period recommended by the American Academy of Pediatrics for oral rehydration. The data did not support the perception by emergency physicians that children treated with IV hydration spend significantly less time than 4 hours in the ED. These findings have implications for addressing one of the major barriers to the use of oral rehydration therapy in the ED setting.

Safety, efficacy, and immunogenicity of a live, quadrivalent human-bovine reassortant rotavirus vaccine in healthy infants

OBJECTIVES

To investigate safety, efficacy, and immunogenicity of live quadrivalent rotavirus vaccine (QRV) containing human-bovine (WC3) reassortant rotavirus serotypes G1, G2, G3, and P1a.

STUDY DESIGN

This was a randomized, double-blinded, placebo-controlled trial. During 1993 to 1994, at 10 US study sites, 439 healthy infants approximately 2 to 6 months of age, were enrolled to receive 3 doses of oral QRV or placebo at approximately 8-week intervals.

RESULTS

The vaccine was generally well tolerated; no serious vaccine-related adverse experiences were reported. Risk differences and 95% confidence intervals suggested no differences between vaccine and placebo recipients in the incidences of fever, irritability, vomiting, or diarrhea during the 14 days after any dose. QRV was 74.6% efficacious (95% CI: 49.5%, 88.3%) in preventing rotavirus acute gastroenteritis (AGE), regardless of severity and 100% efficacious (95% CI: 43.5%, 100%) in preventing severe rotavirus AGE through one rotavirus season. Serotype G1 was identified in most infants with rotavirus AGE. A >or=3-fold rise in serum neutralizing antibody to G1 was observed in 57% (45/79) of vaccinees. A >or=3-fold rise in serum anti-rotavirus IgA and fecal anti-rotavirus IgA was observed in 88% (162/185) and 65% (104/159) of vaccinees, respectively.

CONCLUSIONS

QRV was generally well tolerated, immungenic, and highly effective against rotavirus gastroenteritis.

Rotavirus vaccine for preventing diarrhoea

BACKGROUND

Rotaviruses cause viral gastroenteritis and result in more deaths from diarrhoea in children under 5 years of age than any other single agent, particularly in low- and middle-income countries.

OBJECTIVES

To assess rotavirus vaccines in relation to preventing rotavirus diarrhoea, death, and adverse events.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group's trial register (October 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to October 2003), EMBASE (January 1980 to October 2003), LILACS (1982 to October 2003), Biological Abstracts (January 1982 to October 2003), reference lists of articles, and contacted researchers and rotavirus vaccine manufacturers.

SELECTION CRITERIA

Randomized controlled trials comparing rotavirus vaccines to placebo, no intervention, or other rotavirus vaccines in children and adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial methodological quality, and contacted trial authors for additional information.

MAIN RESULTS

Sixty-four trials provided information on efficacy and safety of three main types of rotavirus vaccine (bovine, human, and rhesus) for 21,070 children. Different levels of efficacy were demonstrated with different vaccines varying from 22 to 89% to prevent one episode of rotavirus diarrhoea, 11 to 44% to prevent one episode of all-cause diarrhoea, and 43 to 90% to prevent one episode of severe rotavirus diarrhoea. Rhesus vaccine demonstrated a similar efficacy against one episode of rotavirus diarrhoea (37 and 44% respectively), and one episode of all-cause diarrhoea (around 15%) for trials performed in high and middle-income countries. Results on mortality and safety of the vaccines were scarce and incomplete. We noticed important heterogeneity among the pooled studies and were unable to discard a biased estimation of effect.

REVIEWER'S CONCLUSIONS

Current evidence shows that rhesus rotavirus vaccines (particularly RRV-TV) and the human rotavirus vaccine 89-12 are efficacious in preventing diarrhoea caused by rotavirus and all-cause diarrhoea. Evidence about safety, and about mortality or prevention of severe outcomes, is scarce and inconclusive. Bovine rotavirus vaccines were also efficacious, but safety data are not available. Trials of new rotavirus vaccines will hopefully improve the evidence base. Randomized controlled trials should be performed simultaneously in high-, middle-, and low-income countries.

Effect of oral administration of tormentil root extract (Potentilla tormentilla) on rotavirus diarrhea in children: a randomized, double blind, controlled trial

OBJECTIVES

To determine the effectiveness of tormentil root extract (TRE) for treatment of rotavirus diarrhea in children.

BACKGROUND

Rotavirus, one of the most widely spread pathogens of acute, dehydrating diarrhea in children, is estimated to cause >800 000 annual deaths of young children in developing countries. Currently no rotavirus vaccine is available. Management involves rehydration therapy. Available antiperistaltic or antisecretory drugs to reduce the severity of diarrhea can cause serious side effects in children.

METHODS

A randomized, double blinded, placebo-controlled trial was conducted at Children's Hospital for Infectious Diseases #3, St. Petersburg, Russia in 40 children ranging in age from 3 months to 7 years with rotavirus diarrhea. We constructed 2 groups for comparison: a treatment group that consisted of 20 children treated with tormentil root extract; and a control group of 20 children who received a placebo. All patients received 3 drops of tormentil root extract or placebo per year of life, three times daily until discontinuation of diarrhea, or a maximum of 5 days. An objective method was used to evaluate diarrhea, and physical examination was used to assess degree of dehydration in children.

RESULTS

The duration of diarrhea in the tormentil root extract treatment group was 3 days, compared with 5 days in the control group (P < 0.0001). In the treatment group 8 of 20 (40%) children were diarrhea-free 48 h after admission to the hospital, compared with 1 of 20 (5%) in the control group (P < 0.0001). Subjects in the treatment group received smaller volumes of parenteral fluids than subjects in the control group.

CONCLUSIONS

The administration of tormentil root extract in controlled doses shortened the duration of rotavirus diarrhea and decreased the requirement for rehydration solutions. Tormentil root extract appears to be an effective measure to treat rotavirus diarrhea in children.

A survey of pediatricians on the reintroduction of a rotavirus vaccine

OBJECTIVE

Rhesus-based rotavirus tetravalent vaccine (RRV-TV; RotaShield) was withdrawn voluntarily from the market in October 1999, and recommendations for use were suspended. Rotavirus infection continues to be a significant health problem affecting children worldwide. The objective of this study was to investigate whether pediatricians would either reconsider using RRV-TV or consider other, newer, and presumably safer rotavirus vaccines if they were recommended routinely and to determine factors that influence their opinion.

METHODS

A questionnaire was sent to a random sample of 250 members of the Wisconsin Chapter of the American Academy of Pediatrics (AAP) and to 437 randomly selected members of the Georgia Chapter of the AAP. Nonresponders received reminder questionnaires.

RESULTS

Of the 687 pediatricians surveyed, 384 (56%) responded. Responses from 319 eligible immunization providers were included in the final analysis. Although only 15% of respondents reported that they would give RRV-TV if it were available today, 94% reported that they would use a new rotavirus vaccine if proved to be safer than RRV-TV and if recommended by the AAP and Advisory Committee on Immunization Practices for routine use among infants. Barriers to reintroducing a rotavirus vaccine were fear of adverse reactions among 95% of pediatricians, followed by potential high vaccine cost (63%) and amount of time required to educate parents (57%).

CONCLUSIONS

Pediatricians reported that they would use a rotavirus vaccine if it was safer than RRV-TV and routinely recommended by the AAP and the Advisory Committee on Immunization Practices.

Intussusception, rotavirus, and oral vaccines: summary of a workshop

Rotavirus gastroenteritis continues to cause substantial morbidity and mortality worldwide, despite widespread breastfeeding and use of oral rehydration therapy. This burden of disease indicates that an effective, safe rotavirus vaccine is needed, and in 1998 the first rhesus-human reassortant rotavirus tetravalent vaccine, Rotashield, was licensed in the United States. However, the recommendations for its use were withdrawn in 1999 because of the recognition of an uncommon but serious adverse event, intussusception. A workshop in September 2001 was held to review the subsequent developments and research regarding this association, the proceedings of which are summarized here. Although the pathogenesis of this association remains unknown, epidemiologic evidence supports a causal relationship, with a population attributable risk of approximately 1 per 10 000 (range of 1 in 5000 to 1 in 12 000) vaccine recipients. Whether this association will exist with other candidate rotavirus vaccine strains and whether the attributable risk for intussusception would be similar in other populations administered this vaccine are unclear. Because perceptions of vaccine safety derive from the relative disease burdens of the illness prevented and adverse events induced, the acceptance of rare adverse events may vary substantially in different settings. Nevertheless, a continuing consensus on the need for a safe and effective vaccine to prevent rotavirus gastroenteritis, especially for use in developing countries, exists.

Rotavirus vaccines: development, current issues and future prospects

The potential benefit of safe and effective rotavirus vaccination in reducing morbidity and especially mortality from rotavirus gastroenteritis among children in developing countries has long been recognised. More recently, the focus of attention shifted to developed countries, where cost-effectiveness analyses justified the routine introduction of rotavirus vaccines into childhood immunisation schedules. The recent withdrawal in the U.S.A. of the first licensed rotavirus vaccine (the tetravalent rhesus reassortant rotavirus vaccine), following investigation into reports of intussusception among a number of vaccinees, has directed attention once more towards rotavirus vaccine use in developing countries. However, issues relating to vaccine safety, efficacy, and cost, remain to be overcome before widespread introduction of rotavirus vaccines can be anticipated.

The future of rotavirus vaccines

In 1998, a simian-human reassortant rotavirus vaccine was licensed and recommended for routine use in children. Within 1 year, however, the vaccine was found to be a cause of intussusception, estimated to be approximately 1 case per 10,000 immunized children, and the recommendations were withdrawn. Although the etiology and pathogenesis of vaccine-associated intussusception remain unclear, immunologic studies suggest several hypotheses. Development of new rotavirus vaccines necessitates the need for large, prelicensure, clinical trials to determine safety. Candidate vaccines currently in clinical trials include a bovine-human reassortant pentavalent vaccine and an attenuated human rotavirus monovalent vaccine. Important issues to be addressed include the acceptable, if any, degree of risk of developing intussusception and economic issues concerning the distribution of the vaccine in developing countries. The continuing interest of pharmaceutical companies in developing a safe and effective vaccine is encouraging, especially given the enormous burden of rotavirus disease in developing countries.