Rotavirus vaccination: a risk factor for intussusception?

The double target sign as ultrasonographic finding in a case of double intussusception: A case report

Intussusception is one of the common conditions in children presenting with abdominal pain. The exact etiology of intussusception is unknown. Lead point is not identified in the majority of cases in children. Commonly, radiographic evidence suggests the presence of a target sign is diagnosis of intussusception. However, the presence of a double target sign in the case of intussusception is rare and depicts the presence of double intussusception. We present a case report of a 1-year-old child who presented to the emergency department with excessive crying for more than 10 hours. After the initial clinical assessment and acute management, an abdominal ultrasound revealed a double target sign on the sub-hepatic and left para-umbilical region which suggested double intussusception. No lead point was identified in our case. Early diagnosis and prompt treatment are the mainstay of management in such cases.

Quantitative Benefit-Risk Models Used for Rotavirus Vaccination: A Systematic Review

Background

Although rotavirus vaccines have proven to prevent the risk of rotavirus gastroenteritis (RVGE) in children under 5 years old, they are also associated with an increased transient risk of intussusception (IS). Several quantitative benefit-risk models (qBRm) are performed to measure this balance in hospitalizations and deaths prevented versus the ones induced.

Method

In this study, our objective was to provide a complete overview of qBRm used for rotavirus vaccination. We systematically searched 3 medical literature databases to identify relevant articles, in English, that were published between 2006 and 2019.

Results

Of the 276 publications screened, 14 studies using qBRm for rotavirus vaccination were retained, based on preselected criteria. Four were performed in low- and middle-income countries. Almost all (13 of 14) displayed the following characteristics: force of infection assumed to be constant over time (static model), indirect effect of rotavirus vaccination (herd effect) not considered, closed model (individuals not allowed to enter and/or exit the model over time), and aggregated level (no tracking of individual's behavior). Most of the models were probabilistic (9 of 14) and reported sensitivity and/or scenario analyses (12 of 14). Input parameter values varied across studies. Selected studies suggest that, depending on the models used, for every IS hospitalization and death induced, vaccination would prevent, respectively, 190-1624 and 71-743 RVGE-related hospitalizations and deaths.

Conclusions

The benefits of rotavirus vaccination were shown to largely exceed the increased risk of IS, across all studies. Future research aiming to harmonize qBRm for rotavirus vaccination should ensure the comparability of studies and provide additional information for regulatory authorities, physicians, and patients.

Updated cost-effectiveness and risk-benefit analysis of two infant rotavirus vaccination strategies in a high-income, low-endemic setting

BACKGROUND AND OBJECTIVE

Since 2013, a biennial rotavirus pattern has emerged in the Netherlands with alternating high and low endemic years and a nearly 50% reduction in rotavirus hospitalization rates overall, while infant rotavirus vaccination has remained below 1% throughout. As the rotavirus vaccination cost-effectiveness and risk-benefit ratio in high-income settings is highly influenced by the total rotavirus disease burden, we re-evaluated two infant vaccination strategies, taking into account this recent change in rotavirus epidemiology.

METHODS

We used updated rotavirus disease burden estimates derived from (active) surveillance to evaluate (1) a targeted strategy with selective vaccination of infants with medical risk conditions (prematurity, low birth weight, or congenital conditions) and (2) universal vaccination including all infants. In addition, we added herd protection as well as vaccine-induced intussusception risk to our previous cost-effectiveness model. An age- and risk-group structured, discrete-time event, stochastic multi-cohort model of the Dutch pediatric population was used to estimate the costs and effects of each vaccination strategy.

RESULTS

The targeted vaccination was cost-saving under all scenarios tested from both the healthcare payer and societal perspective at rotavirus vaccine market prices (€135/child). The cost-effectiveness ratio for universal vaccination was €51,277 at the assumed vaccine price of €75/child, using a societal perspective and 3% discount rates. Universal vaccination became cost-neutral at €32/child. At an assumed vaccine-induced intussusception rate of 1/50,000, an estimated 1707 hospitalizations and 21 fatal rotavirus cases were averted by targeted vaccination per vaccine-induced intussusception case. Applying universal vaccination, an additional 571 hospitalizations and <  1 additional rotavirus death were averted in healthy children per vaccine-induced intussusception case.

CONCLUSION

While universal infant rotavirus vaccination results in the highest reductions in the population burden of rotavirus, targeted vaccination should be considered as a cost-saving alternative with a favorable risk-benefit ratio for high-income settings where universal implementation is unfeasible because of budget restrictions, low rotavirus endemicity, and/or public acceptance.

Risk of Intussusception After Rotavirus Vaccination

BACKGROUND

In 2013, the German Standing Committee on Vaccination (Ständige Impfkommission, STIKO) recommended rotavirus (RV) vaccination for all infants while stating that this mildly increased the risk of intussusception, a potentially life-threatening event. Since this recommendation was issued, multiple observational studies on this topic designed as self-controlled case series (SCCS) have been published. The SCCS design is particularly suitable for the study of rare adverse effects of medications.

METHODS

We systematically searched the literature for SCCS studies on the risk of intussusception after RV vaccination. Relative risks (RR) corresponding to different doses of vaccine were summarized in a meta-analysis, and attributable risks (AR) were calculated.

RESULTS

Of the 16 initially identified studies, 10 with a predominantly low risk of bias were considered in the analysis. The RR for intussusception was 5.71 (95% confidence interval [4.50; 7.25]) 1-7 days after the first dose, 1.69 [1.33; 2.14] after the second, and 1.14 [0.75; 1.74] after the third. The AR for children of the age at which RV vaccination is recommended was 1.7 [1.1; 2.7] additional intussusceptions per 100 000 vaccinated children after the first dose and 0.25 [0.16; 0.40] after the second. If >3-month-old infants are vaccinated, the AR is higher: 5.6 [4.3; 7.2] per 100 000 after the first dose and 0.81 [0.63; 1.06] per 100 000 after the second.

CONCLUSION

RV vaccination is associated with a markedly elevated RR and a mildly elevated AR for intussusception 1-7 days after the first dose. Physicians should begin the series of vaccinations at age 6-12 weeks, as recommended by the STIKO, because the risk of intussusception is higher afterward. Current health insurance company claim data indicate that 11.2% of infants are still receiving the first dose of the vaccine at ages above 3 months. The parents of vaccinated children should be informed about the possible signs of intussusception (colicky pain, bilious vomiting, and red "currant jelly" stool).

Efficacy, safety and effectiveness of licensed rotavirus vaccines: a systematic review and meta-analysis for Latin America and the Caribbean

BACKGROUND

RotaTeq™ (RV5; Merck & Co. Inc., USA) and Rotarix™ (RV1, GlaxoSmithKline, Belgium) vaccines, developed to prevent rotavirus diarrhea in children under five years old, were both introduced into national immunization programs in 2006. As many countries in Latin America and the Caribbean have included either RV5 or RV1 in their routine childhood vaccination programs, we conducted a systematic review and meta-analysis to analyze efficacy, safety and effectiveness data from the region.

METHODS

We conducted a systematic search in PubMed, EMBASE, Scielo, Lilacs and the Cochrane Central Register, for controlled efficacy, safety and effectiveness studies published between January 2000 until December 2011, on RV5 and RV1 across Latin America (where both vaccines are available since 2006). The primary outcome measures were: rotavirus-related gastroenteritis of any severity; rotavirus emergency department visits and hospitalization; and severe adverse events.

RESULTS

The results of the meta-analysis for efficacy show that RV1 reduced the risk of any-severity rotavirus-related gastroenteritis by 65% (relative risk (RR) 0.35, 95% confidence interval (CI) 0.25; 0.50), and of severe gastroenteritis by 82% (RR 0.18, 95%CI 0.12; 0.26) versus placebo. In trials, both vaccines significantly reduced the risk of hospitalization and emergency visits by 85% (RR 0.15, 95%CI 0.09; 0.25) for RV1 and by 90% (RR 0.099, 95%CI 0.012; 0.77) for RV5. Vaccination with RV5 or RV1 did not increase the risk of death, intussusception, or other severe adverse events which were previously associated with the first licensed rotavirus vaccine. Real-world effectiveness studies showed that both vaccines reduced rotavirus hospitalization in the region by around 45-50% for RV5 (for 1 to 3 doses, respectively), and, by around 50-80% for RV1 (for 1 to 2 doses, respectively). For RV1, effectiveness against hospitalization was highest (around 80-96%) for children vaccinated before 12 months of age, compared with 5-60% effectiveness in older children. Both vaccines were most effective in preventing more severe gastroenteritis (70% for RV5 and 80-90% for RV1) and severe gastroenteritis (50% for RV5 and 70-80% for RV1).

CONCLUSION

This systematic literature review confirms rotavirus vaccination has been proven effective and well tolerated in protecting children in Latin America and the Caribbean.

Analysis of hospitalizations due to intussusception in Sicily in the pre-rotavirus vaccination era (2003-2012)

BACKGROUND

Intussusception is the most common cause of bowel obstruction in infants with an incidence ranging from 9-328 cases per 100,000 infants aged 0-11 months. Causes underlining this clinical manifestation are still unknown. Possible relationship with a withdrawn tetravalent rotavirus vaccine was not confirmed by post-licensure studies and actually no increased risk of intussusception was found between infants vaccinated with both the recently licensed rotavirus vaccines. Aim of this study is to analyze the intussusception hospitalizations in Sicily from 2003 to 2012 before the introduction of rotavirus universal vaccination and its possible relation with rotavirus gastroenteritis trend.

METHODS

Were collected data from hospital discharge records occurred from 1(st) January 2003 to 31(st) December 2012 in Sicily. Intussusception cases were defined as all hospitalizations with an ICD-9-CM code of 560.0 on any discharge diagnoses. As a proxy for the severity of cases were considered ICD-9-CM procedure codes accounting for surgical or radiologic reduction.

RESULTS

A total of 340 intussusception cases were hospitalized in Sicily from 2003 to 2012 in children aged 0-59 months. 46.8 % occurred in the age class 0-11 months. Hospitalization rate for intussusception was 11.4 cases per 100,000 per year (32.6 cases per 100,000 among 0-11 months children; 7.3 cases per 100,000 among 12-59 months children), with a M:F sex ratio of 1.8. During hospitalization only 25 % of intussusceptions had a spontaneous resolution, 56.5 % of cases required a surgical intervention. From 2003 to 2012 intussusception cases were equally distributed during the year without any seasonality, while gastroenteritis hospitalizations due to rotavirus infection have a typically late winter and spring distribution.

CONCLUSIONS

In Sicily from 2003 to 2012 hospitalizations due to intestinal invagination were higher among children aged 0-11 months with observed rates similar to other European countries. Regional baseline data analysis of intussusception among 0-59 children is recognized as an evidence-based public health strategy by international health authorities. Indeed, this strategy is necessary to compare any post-licensure age or sex-related change in intussusception trend after universal rotavirus vaccination introduction.

Risk of Intussusception After Rotavirus Vaccination: Meta-analysis of Postlicensure Studies

BACKGROUND

Postlicensure surveillance studies suggest a small temporal increase in the risk for intussusception with both currently available rotavirus vaccines (RV1; Rotarix, GSK and RV5; RotaTeq, Merck & Co., Inc.). This meta-analysis was undertaken to provide a single overall estimate of the relative risk of intussusception during the 7-day period after administration of RV1 and RV5.

METHODS

Meta-analysis based on estimates of relative risk and corresponding 95% confidence intervals from 5 postlicensure studies providing an estimate of risk of intussusception during the 7-day period after administration of dose 1 and/or dose 2 of RV1 and/or RV5, based on active and/or passive surveillance, for confirmed intussusception cases (Brighton or other method of case confirmation). For each vaccine, the relative risk of intussusception was estimated postdose 1 and postdose 2. Results were pooled using the inverse variance method using both fixed-effect and random-effect models.

RESULTS

The overall estimate of relative risk of intussusception during the 7 days postdose 1 was 5.4 (95% confidence interval: 3.9-7.4, 3 studies) for RV1 and 5.5 (3.3-9.3, 3 studies) for RV5. The overall estimate of relative risk of intussusception during the 7 days postdose 2 was 1.8 (1.3-2.5, 4 studies) for RV1 and 1.7 (1.1-2.6, 3 studies) for RV5.

CONCLUSIONS

This meta-analysis showed a similar increased risk of intussusception, during the first 7 days after administration of dose 1 and, to a lesser extent, dose 2, for both currently available rotavirus vaccines. This suggests that intussusception may be a class effect of currently available oral rotavirus vaccines.