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

No increased risk of intussusception after pentavalent rotavirus vaccination in China: a retrospective birth cohort using electronic health records of Ningbo city

Some post-licensure studies have shown a potential increased risk of intussusception following vaccination with rotavirus vaccines. This is the first study that aimed to assess the incidence and risk of intussusception within 90 days after vaccination with RotaTeq in Chinese infants. A population-based birth cohort from 27th November 2018 to 30th June 2021 included all newborns in Ningbo city. The records of intussusception were identified through the ICD-10 code K56.1 or Chinese keywords "Chang Tao" from all hospital discharge records. Each episode was confirmed in line with the Brighton criteria, and only Brighton level 1 cases were included. The association of RotaTeq vaccination and intussusception was evaluated using the Poisson regression. A total of 108,405 eligible subjects from birth cohort were eligible, with 52.30% males. Among them, 26, 847 (24.77%) infants received at least one dose of RotaTeq, and 95.52% of them were fully vaccinated, with 76, 934 doses in total. After adjudication, none of the cases occurred post first, or second dose, the cumulative number of cases that occurred 1-7, 1-14, 1-21, 1-42, and 1-90 days post third dose was 0, 1, 1, 3, and 7, respectively. Adjusting for age, sex, birth year, birth season and location, the incidence rate ratio of intussusception after RotaTeq vaccination was 0.90 (90% two-sided CI: 0.46, 1.75). Increasing age and male gender were associated with higher risk of intussusception. In summary, no increased risk of IS was observed following 3 months of RotaTeq vaccination in this study.

Impact of vaccination with different types of rotavirus vaccines on the incidence of intussusception: a randomized controlled meta-analysis

Background

Intussusception is a prevalent pediatric issue causing acute abdominal pain, with potential links to rotavirus vaccines. The variety of these vaccines has grown in recent years. This meta-analysis study aims to evaluate the impact of various rotavirus vaccines on intussusception incidence.

Methods

We executed a thorough search across databases like PubMed, Cochrane Library, Embase, and Web of Science, leading to the selection of 15 credible randomized controlled trials (RCTs) that encompass various types of rotavirus vaccines. From each study, we extracted essential details such as vaccine types and intussusception occurrences. We assessed the risk of bias using the Cochrane Collaboration's tool, conducted statistical analysis with R (version 4.2.3), determined relative risk (RR) using a random effects model, and performed a subgroup analysis for vaccines of differing brands and types.

Results

We included 15 randomized controlled studies from various countries. While intussusception incidence differed between vaccinated and control groups, this difference was not statistically significant. The overall risk ratio (RR), calculated using a random effects model, was 0.81, with a 95% confidence interval of [0.53, 1.23]. This crossing 1 shows that vaccination didn't notably change disease risk. Additionally, the 0% group heterogeneity suggests consistency across studies, strengthening our conclusions. Subgroup analysis for different vaccine brands and types (RV1 (Rotarix, Rotavac, RV3-BB), RV3 (LLR3), RV5 (RotasiiL, RotaTeq), and RV6) showed no significant variation in intussusception incidence. Despite variations in RR among subgroups, these differences were not statistically significant (P > 0.05).

Conclusions

Our study indicates that rotavirus vaccination does not significantly increase the incidence of intussusception. Despite varying impacts across different vaccine brands and types, these variations are insignificant. Given the substantial benefits outweighing the risks, promoting the use of newly developed rotavirus vaccines remains highly valuable.

Systematic Review Registration

www.crd.york.ac.uk/prospero/, Identifier CRD42023425279.

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

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

Impact of polio vaccines (oral polio vaccine - OPV or inactivated polio vaccine - IPV) on rotavirus vaccine-associated intussusception

Although safe, rotavirus vaccines have been associated with increased intussusception risk. In Brazil, after the oral human rotavirus vaccine (OHRV) introduction in the childhood immunization, in 2006, increased intussusception risk was identified after the second OHRV dose, whereas in other countries, higher risk was associated to the first vaccine dose. It was hypothesized that the concomitant use of oral poliovirus vaccine (OPV) in Brazil might explain this difference. In 2012, the inactivated polio vaccine (IPV) was adopted in the first two doses of Brazilian childhood immunization schedule, creating an opportunity to study the subject. Our objective was analyzing the impact of polio vaccines on rotavirus-associated intussusception. We used surveillance data on intussusception in infants living in São Paulo State. Two periods were considered: an OPV-period (March 2006 to June 2012) and an IPV-period (October 2012 to December 2017). The period from June to September 2012 were considered as transition. Self-controlled case series analysis with event-dependent exposure was performed, considering two risk periods (7 and 21 days post-vaccination). We identified 325 intussusception cases in infants reported to the surveillance systems during the study period. The statistical analysis included 221 cases that occurred within 60 days after vaccination. Overall, a higher intussusception risk was observed in the first week after vaccination for both the first (Relative Incidence [RI] = 4.3, 95%CI 2.8-6.5, p < .001) and second vaccine doses (RI = 4.2, 95%CI 2.7-6.4; p < .001). There were no statistically significant differences in intussusception risk according to the rotavirus vaccine dose and the polio vaccine (OPV or IPV) administered concomitantly.

Impact of industry sponsorship on the quality of systematic reviews of vaccines: a cross-sectional analysis of studies published from 2016 to 2019

BACKGROUND

Systematic reviews (SRs) provide the highest level of evidence and inform evidence-based decision making in health care. Earlier studies found association with industry to be negatively associated with methodological quality of SRs. However, this has not been investigated in SRs on vaccines.

METHODS

We performed a systematic literature search using MEDLINE and EMBASE in March 2020. The results were restricted to those published between 2016 and 2019 with no language restrictions. Study characteristics were extracted by one person and checked by an experienced reviewer. The methodological quality of the SRs was assessed with the AMSTAR 2 tool by multiple reviewers after a calibration exercise was performed. A summary score for each SR was calculated. The Mann-Whitney U test and Fisher's exact test were performed to compare both groups.

RESULTS

Out of 185 SRs that met all inclusion criteria, 27 SRs were industry funded. Those were matched with 30 non-industry funded SRs resulting in a total sample size of 57. The mean AMSTAR 2 summary score across all SRs was 0.49. Overall, the median AMSTAR 2 summary score was higher for the non-industry funded SRs than for the industry-funded SRs (0.62 vs. 0.36; p < .00001). Lower ratings for industry funded SRs were consistent across all but one AMSTAR 2 item, though significantly lower only for three specific items.

CONCLUSION

The methodological quality of SRs in vaccination is comparable to SRs in other fields, while it is still suboptimal. We are not able to provide a satisfactory explanation why industry funded SRs had a lower methodological quality than non-industry funded SRs over recent years. Industry funding is an important indicator of methodological quality for vaccine SRs and should be carefully considered when appraising SR quality.

Severity of Rotavirus-Vaccine-Associated Intussusception: Prospective Hospital-Based Surveillance, Australia, 2007-2018

BACKGROUND

Multiple studies have shown an association between intussusception (IS) and receipt of monovalent or pentavalent rotavirus vaccine (RV) in the previous 21 days. Disease severity is an important consideration for risk-benefit evaluations of RV, but no studies have compared the severity of IS within 21 days of vaccination (vaccine-associated, VA) and later (not temporally-associated, VNA).

METHODS

We used active hospital-based surveillance in the Australian Paediatric Active Enhanced Disease Surveillance (PAEDS) network (July 2007 to February 2018) to identify infants ≤9 months of age meeting Brighton level 1 criteria for IS. We used five severity levels: (1) no surgery and length of stay (LOS) ≤1 day, (2) no surgery and LOS ≥2 days, (3) surgery, no bowel resection, (4) bowel resection, and (5) ICU admission.

RESULTS

Of 323 eligible cases, 87 (26.9%) were VA and 236 (73.1%) VNA. VA-IS cases (median 21 weeks; 24.1% ≤14 weeks) were significantly younger than VNA-IS cases (median 28 weeks, 7.2% ≤14 weeks). Cases 0-≤14 weeks of age were significantly more likely than cases ≥25 weeks to require bowel resection (relative risk ratio 4.6, 95% CI, 1.48-14.3). This effect was not associated with RV. After adjustment for age and sex, VA-IS was not significantly overrepresented in severity levels 2-5; adjusted RRR of 1.37 (95% CI: 0.61-3.11) for bowel resection in cases 0-≤14 weeks of age.

CONCLUSIONS

IS was uncommon but significantly more severe under 14 weeks of age. After adjustment for age and sex, IS severity was not related to RV.

Evaluation of a bivalent recombinant vaccine candidate targeting norovirus and rotavirus: Antibodies to rotavirus NSP4 exert antidiarrheal effects without virus neutralization

We previously found that when tandemly expressed with S_R69A -VP8*, nonstructural protein 4 (NSP4) of the rotavirus Wa strain exerts a minor effect on elevating the antibody responses targeting the rotavirus antigen VP8* of the 60-valent nanoparticle S_R69A -VP8* but could fully protect mice from diarrhea induced by the rotavirus strain Wa. In this study, we chose comparably less immunogenic norovirus 24-valent P particles with homogenous (i.e., VP8* from rotavirus) and heterogeneous (i.e., protruding domain of norovirus) antigens and in more challenging rotavirus SA11 strain-induced diarrhea mouse models to evaluate its main role in recombinant gastroenteritis virus-specific vaccines. The results showed that although as an adjuvant NSP4 exerted limited effects on the elevation of norovirus-specific or VP8*-specific neutralizing antibody production, as an antigen it could confer potent protection, particularly when synergized with VP8*, in rotavirus SA11 strain-induced diarrhea mouse models, possibly blocking the invasion of the intestinal wall by enterotoxin. NSP4 may be unnecessary for other recombinant vaccines as adjuvants, and its display mode should be evaluated specifically to avoid blocking coexpressed antigens in the norovirus P particles. This article is protected by copyright. All rights reserved.

Review of Over 15 Years Postmarketing Safety Surveillance Spontaneous Data for the Human Rotavirus Vaccine (Rotarix) on Intussusception

Introduction

Rotavirus (RV) is the most common cause of acute gastroenteritis in children <5 years of age worldwide, and vaccination reduces the disease burden. Evidence from postmarketing surveillance studies suggested an increased risk of intussusception (IS) in infants post-RV vaccination. An overall positive benefit–risk balance for the human RV vaccine (HRV) Rotarix (GlaxoSmithKline [GSK], Belgium) has been established and recent findings indicate an indirect effect of reduced IS over the long term.

Objective

The aim of this study was to discuss spontaneous data from the GSK worldwide safety database on IS post-Rotarix administration.

Methods

The database was reviewed for all spontaneous IS cases from 2004 to 2020. Additionally, an observed versus expected (O/E) analysis was done for adverse events attributed to IS. Data were reviewed as overall worldwide and stratified by region (Europe/USA/Japan) and dose.

Results

A male predominance of IS patients was observed, consistent with earlier reports. The most frequently reported events in confirmed IS cases (Brighton Collaboration Working Group [BCWG] level 1) with time to onset ≤ 30 days post-vaccination were vomiting (55.8%), haematochezia (47.2%), and crying (21.1%). The observations from the IS spontaneous cases review and results of the O/E analysis are consistent with the known IS safety profile of RV vaccines: a transient increased incidence of IS post-vaccination (primarily in Europe/Japan/worldwide), mostly within 7 days postdose 1.

Conclusion

Since the outcomes of early IS management are favourable over delayed management, healthcare professionals should inform parents about the importance of seeking immediate medical advice in case of unusual behaviour of the vaccinated infant. GSK continues to monitor the IS risk post-Rotarix administration through routine pharmacovigilance activities.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01141-4.

Rotavirus (RV) is the most common cause of acute gastroenteritis and a major cause of death in young children worldwide. Vaccination has been instrumental in reducing the impact of RV disease. Real-world evidence suggests an increased risk of intussusception (an infrequent type of bowel obstruction) in infants following RV vaccination. We reviewed IS cases reported spontaneously worldwide in children following a two-dose vaccination with the human RV vaccine (Rotarix, GlaxoSmithKline [GSK]) since its launch in 2004. We observed that (1) IS occurred more frequently 7 days after the first dose and, to a lesser extent, after the second dose; (2) boys were more frequently affected than girls (56.3%); (3) of 862 confirmed reported cases, 557 required hospitalisation; and (4) surgical intervention was required for 294 of 557 hospitalised cases. We used statistical analysis to assess whether the number of cases observed would be higher or lower than the natural occurrence of IS (irrespective of vaccination). These results were in line with the known RV vaccine safety profile. It is important to constantly monitor the real-world safety profile of RV vaccines in the postmarketing setting. Since the outcomes of early management of IS are favourable compared with delayed management, healthcare professionals should inform parents to seek immediate medical advice if they observe unusual behaviour in their vaccinated child. In conclusion, our analyses on data of a large patient pool for this rare event reinforce the favourable safety profile of human RV vaccine and the benefits of vaccination in young children.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Systematic Evaluation of Kinetics and Distribution of Muscle and Lymph Node Activation Measured by 18F-FDG- and 11C-PBR28-PET/CT Imaging, and Whole Blood and Muscle Transcriptomics After Immunization of Healthy Humans With Adjuvanted and Unadjuvanted Vaccines

Systems vaccinology has been applied to detect signatures of human vaccine induced immunity but its ability, together with high definition in vivo clinical imaging is not established to predict vaccine reactogenicity. Within two European Commission funded high impact programs, BIOVACSAFE and ADITEC, we applied high resolution positron emission tomography/computed tomography (PET/CT) scanning using tissue-specific and non-specific radioligands together with transcriptomic analysis of muscle biopsies in a clinical model systematically and prospectively comparing vaccine-induced immune/inflammatory responses. 109 male participants received a single immunization with licensed preparations of either AS04-adjuvanted hepatitis B virus vaccine (AHBVV); MF59C-adjuvanted (ATIV) or unadjuvanted seasonal trivalent influenza vaccine (STIV); or alum-OMV-meningococcal B protein vaccine (4CMenB), followed by a PET/CT scan (n = 54) or an injection site muscle biopsy (n = 45). Characteristic kinetics was observed with a localized intramuscular focus associated with increased tissue glycolysis at the site of immunization detected by ¹⁸F-fluorodeoxyglucose (FDG) PET/CT, peaking after 1–3 days and strongest and most prolonged after 4CMenB, which correlated with clinical experience. Draining lymph node activation peaked between days 3–5 and was most prominent after ATIV. Well defined uptake of the immune cell-binding radioligand ¹¹C-PBR28 was observed in muscle lesions and draining lymph nodes. Kinetics of muscle gene expression module upregulation reflected those seen previously in preclinical models with a very early (~6hrs) upregulation of monocyte-, TLR- and cytokine/chemokine-associated modules after AHBVV, in contrast to a response on day 3 after ATIV, which was bracketed by whole blood responses on day 1 as antigen presenting, inflammatory and innate immune cells trafficked to the site of immunization, and on day 5 associated with activated CD4+ T cells. These observations confirm the use of PET/CT, including potentially tissue-, cell-, or cytokine/chemokine-specific radioligands, is a safe and ethical quantitative technique to compare candidate vaccine formulations and could be safely combined with biopsy to guide efficient collection of samples for integrated whole blood and tissue systems vaccinology in small-scale but intensive human clinical models of immunization and to accelerate clinical development and optimisation of vaccine candidates, adjuvants, and formulations.

Exploring rotavirus proteome to identify potential B- and T-cell epitope using computational immunoinformatics

Rotavirus is the most common cause of acute gastroenteritis in infants and children worldwide. The functional correlation of B- and T-cells to long-lasting immunity against rotavirus infection in the literature is limited. In this work, a series of computational immuno-informatics approaches were applied and identified 28 linear B-cells, 26 conformational B-cell, 44 T_C cell and 40 T_H cell binding epitopes for structural and non-structural proteins of rotavirus. Further selection of putative B and T cell epitopes in the multi-epitope vaccine construct was carried out based on immunogenicity, conservancy, allergenicity and the helical content of predicted epitopes. An in-silico vaccine constructs was developed using an N-terminal adjuvant (RGD motif) followed by T_C and T_H cell epitopes and B-cell epitope with an appropriate linker. Multi-threading models of multi-epitope vaccine construct with B- and T-cell epitopes were generated and molecular dynamics simulation was performed to determine the stability of designed vaccine. Codon optimized multi-epitope vaccine antigens was expressed and affinity purified using the E. coli expression system. Further the T cell epitope presentation assay using the recombinant multi-epitope constructs and the T cell epitope predicted and identified in this study have not been investigated. Multi-epitope vaccine construct encompassing predicted B- and T-cell epitopes may help to generate long-term immune responses against rotavirus. The computational findings reported in this study may provide information in developing epitope-based vaccine and diagnostic assay for rotavirus-led diarrhea in children's.

Rotavirus Vaccination Coverage During a Rotavirus Outbreak Resulting in a Fatality at a Subacute Care Facility

BACKGROUND

The introduction of rotavirus vaccine in the United States has reduced rotavirus disease burden, but outbreaks still occur. Complete-series rotavirus vaccination coverage is <75% in the United States, and it might be lower among vulnerable populations. We describe here the clinical characteristics and vaccination status of children during a rotavirus outbreak in a pediatric subacute care facility in 2017.

METHODS

Clinical history, signs and symptoms, and vaccination history were abstracted for the 26 patients residing in the facility during the time of the outbreak. A case-patient was defined as one who experienced 3 or more loose stools in a period of 24 hours with onset between April 17 and May 17, 2017. Stool samples from 14 resident patients were tested for rotavirus with reverse-transcription polymerase chain reaction.

RESULTS

The median patient age at the facility was 2.9 years. Of the 26 resident patients, 22 (85%) met the case definition. One child died. Stool samples from 11 case-patients were positive according to reverse-transcription polymerase chain reaction for rotavirus. Fifteen case-patients were unvaccinated against rotavirus; 3 were partially vaccinated, and 2 were fully vaccinated. Vaccination status could not be completely determined in 2 cases.

CONCLUSIONS

An outbreak of rotavirus affected nearly all resident patients of a subacute care facility and caused 1 death. Because of recommendations against giving rotavirus vaccine in an intensive care setting, infants who require a prolonged intensive care stay might age out of rotavirus vaccine eligibility (the first dose must be given before 15 weeks of age according to Advisory Committee on Immunization Practices recommendations). The result is a vulnerable population of unvaccinated infants who might later congregate in another care setting.

Overview of the Development, Impacts, and Challenges of Live-Attenuated Oral Rotavirus Vaccines

Safety, efficacy, and cost-effectiveness are paramount to vaccine development. Following the isolation of rotavirus particles in 1969 and its evidence as an aetiology of severe dehydrating diarrhoea in infants and young children worldwide, the quest to find not only an acceptable and reliable but cost-effective vaccine has continued until now. Four live-attenuated oral rotavirus vaccines (LAORoVs) (Rotarix^®, RotaTeq^®, Rotavac^®, and RotaSIIL^®) have been developed and licensed to be used against all forms of rotavirus-associated infection. The efficacy of these vaccines is more obvious in the high-income countries (HIC) compared with the low- to middle-income countries (LMICs); however, the impact is far exceeding in the low-income countries (LICs). Despite the rotavirus vaccine efficacy and effectiveness, more than 90 countries (mostly Asia, America, and Europe) are yet to implement any of these vaccines. Implementation of these vaccines has continued to suffer a setback in these countries due to the vaccine cost, policy, discharging of strategic preventive measures, and infrastructures. This review reappraises the impacts and effectiveness of the current live-attenuated oral rotavirus vaccines from many representative countries of the globe. It examines the problems associated with the low efficacy of these vaccines and the way forward. Lastly, forefront efforts put forward to develop initial procedures for oral rotavirus vaccines were examined and re-connected to today vaccines.

Rotavirus vaccination and intussusception: a paradigm shift?

Rotavirus (RV) is one of the leading causes of severe childhood gastroenteritis in children <5 years of age. Several countries have successfully implemented vaccination against RV disease; however, hesitancy to include RV vaccination in the national immunization program exists and relates, among other reasons, to the results of international post-licensure studies of RV vaccines that established an increased risk of intussusception (IS) in infants following immunization. IS is one of the major causes of bowel obstruction in infants between 4 and 10 months of age. Some studies have investigated the etiology of IS, including the role of natural RV infection and available evidence suggests that RV disease may be an independent risk factor for IS. In this regard, the benefit-risk profile of RV vaccination, which is recognized as positive, could potentially turn out to be even more favorable in preventing IS cases triggered by RV disease. However, further research is prompted to quantify the IS risk attributable to RV disease.

Does Rotavirus Vaccination Affect Longer-Term Intussusception Risk in US Infants?

Rotavirus vaccination has been associated with a short-term increased risk of intussusception. Our analysis of insurance claims for 1 858 827 US children with 544 recorded cases of intussusception found a nonsignificant decrease in intussusception (hazard ratio, 0.79 [95% confidence interval, 0.57-1.09]) in fully rotavirus-vaccinated children followed up to the age of 2 years.

Association Between Rotavirus Vaccination and Risk of Intussusception Among Neonates and Infants: A Systematic Review and Meta-analysis

IMPORTANCE

The conclusions from the multiple randomized clinical trials exploring the relationship between development of intussusception and rotavirus vaccination among neonates and infants have been controversial.

OBJECTIVE

To evaluate the association between rotavirus vaccination and risk of intussusception.

DATA SOURCES

For this systematic review and meta-analysis, PubMed, Web of Science, Cochrane library, and Embase databases were searched from January 1, 1999, through December 31, 2018, using no language restrictions. The search terms were rotavirus or RV (rotavirus vaccine) or HRV (human rotavirus vaccine), vaccin*, and intussusception.

STUDY SELECTION

Randomized clinical trials of neonates and infants that compared the risk of intussusception after the vaccination with a placebo group were included.

DATA EXTRACTION AND SYNTHESIS

A fixed-effects model was used to pool the data. Statistical heterogeneity was assessed with Q test and I2 statistic; relative risk (RR), risk difference (RD), and 95% CIs were calculated using the Mantel-Haenszel method.

MAIN OUTCOMES AND MEASURES

The main outcome was the diagnosis of intussusception in the analysis. The pooled and subtotal results of RR, RD, and 95% CI for the risk of intussusception were estimated at 31 days, 1 year, and 2 years after vaccination.

RESULTS

A total of 25 randomized clinical trials including 200 594 participants (104 647 receiving vaccine and 95 947 receiving placebo) in 33 countries from 4 continents were included in this meta-analysis. Twenty cases of definite intussusception were diagnosed within 31 days after rotavirus vaccination, with 11 cases (55%) in the vaccine group and 9 cases (45%) in the placebo group (RD, 0.17 per 10 000 infants [95% CI, -1.16 to 1.50 per 10 000 infants], P = .80; RR, 1.14 [95% CI, 0.49 to 2.64], P = .77). Seventy-four cases were reported within 1 year, with 37 cases (50%) in the vaccine group and 37 cases (50%) in the placebo group (RD, -0.65 per 10 000 infants [95% CI, -2.68 to 1.39 per 10 000 infants], P = .53; RR, 0.84 [95% CI, 0.53 to 1.32], P = .45). Fifty-nine cases were reported within 2 years, with 29 cases (49%) in the vaccine group and 30 cases (51%) in the placebo group (RD, -0.48 per 10 000 infants [95% CI, -3.64 to 2.69 per 10 000 infants], P = .77; RR, 0.91 [95% CI, 0.55 to 1.52], P = .73).

CONCLUSIONS AND RELEVANCE

Results of this systematic review and meta-analysis suggest that monovalent, pentavalent, monovalent human-bovine, oral bovine pentavalent, and human neonatal rotavirus vaccination was not associated with an elevated risk of intussusception among neonates or infants.

Use of Real-world Evidence to Evaluate the Effectiveness of Herpes Zoster Vaccine

This article reviews the use of real-world evidence (RWE) from observational studies to evaluate herpes zoster vaccine effectiveness and complement clinical trial data that have known limitations. The use of RWE with appropriate study designs and cautious interpretation can be informative in decision-making. Understanding the advantages and limitations of studies yielding RWE can facilitate the critical evaluation of findings from different studies. This is a timely issue, as regulatory agencies are considering how RWE can contribute to the assessment of effectiveness in regulatory decision-making.

Rotavirus: Genetics, pathogenesis and vaccine advances

Since its discovery 40 years ago, rotavirus (RV) is considered to be a major cause of infant and childhood morbidity and mortality particularly in developing countries. Nearly every child in the world under 5 years of age is at the risk of RV infection. It is estimated that 90% of RV-associated mortalities occur in developing countries of Africa and Asia. Two live oral vaccines, RotaTeq (RV5, Merck) and Rotarix (RV1, GlaxoSmithKline) have been successfully deployed to scale down the disease burden in Europe and America, but they are less effective in Africa and Asia. In April 2009, the World Health Organization recommended the inclusion of RV vaccination in national immunization programs of all countries with great emphasis in developing countries. To date, 86 countries have included RV vaccines into their national immunization programs including 41 Global Alliance for Vaccines and Immunization eligible countries. The predominant RV genotypes circulating all over the world are G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8], while G12[P6] and G12[P8] are emerging genotypes. On account of the segmented genome, RV shows an enormous genetic diversity that leads to the evolution of new genotypes that can influence the efficacy of current vaccines. The current need is for a global RV surveillance program to monitor the prevalence and antigenic variability of new genotypes to formulate future vaccine development planning. In this review, we will summarize the previous and recent insights into RV structure, classification, and epidemiology and current status of RV vaccination around the globe and will also cover the status of RV research and vaccine policy in Pakistan.

Intussusception Rate Among Under-Five-Children Before Introduction of Rotavirus Vaccine in North India

BACKGROUND

Baseline data on intussusception are needed to compare the intussusception rates following introduction of rotavirus vaccine.

METHODS

A hospital-based bidirectional surveillance (retrospective from 2009 to 2012; and prospective from 2013 to 2015) was set up in a tertiary care hospital in Chandigarh, India, to enrol children <5 years of age admitted with intussusception as per Brighton's classification, to estimate the hospital admission rate. Incidence of intussusception among infants and children <5 years of age was also estimated.

RESULTS

A total of 277 intussusception cases (96 retrospective; 181 prospective) were reported. Majority of cases were males (69.7%) and infants (72%). Median age at diagnosis was 10 months (interquartile range 6-12 months). Nearly 62% cases were treated surgically and 33% radiologically. Incidence was estimated to be 20/100 000 infants, and 5/100 000 children <5 years of age per year, in Chandigarh.

CONCLUSION

Intussusception surveillance system provided background hospital admission and incidence rate before rotavirus vaccine introduction in North India.

Pediatric Intussusception: The Cinnamon Bun Sign

Acute abdominal pain in the pediatric patient is a common clinical symptom often resulting in uncertainty and thus often subsequently leads to a sonographic examination of the abdomen. Sonography is often the modality of choice for pediatric abdominal imaging, and consequently, sonographers should have a fundamental appreciation for the causes of acute abdominal pain in the pediatric population. Intussusception, which is the telescoping of a proximal segment of bowel into a distal segment, is one potential cause of acute abdominal pain for these patients. This review clarifies the etiology and classification of intussusception and provides an overview of the clinical manifestations, sonographic identification, and treatment of this potentially severe disorder. Also, this review provides a novel imaging sign, called the “cinnamon bun” sign, that sonographers can employ while examining patients for possible intussusception. The cinnamon bun sign is a descriptive term that may be used to illustrate a transverse sonographic plane through an intussusception.