Rates of intussusception increase with rotavirus vaccine

1. In children aged 6 to 14 weeks, rates of hospitalization from intussusception post-vaccination with the rotavirus vaccine were significantly elevated by 46% to 101%.

2. No change was observed in the hospitalization rate from intussusception in children 15 to 34 weeks of age.

Evidence Rating Level: 2 (Good)

Study Rundown: Recent studies have identified intussusception as a potential harmful side effect after the first dose of the rotavirus vaccine. In fact, a rotavirus vaccine brand was withdrawn from the market in 1999 because of the increased risk of intussusception after its introduction. The objective of this study was to compare pre-vaccine intussusception hospitalization rates with post-vaccine rates amongst children for whom the vaccine is indicated. This study added four additional years of data to previous research that examined the rates of hospitalization for intussusception after rotavirus vaccination; results of this study were found to be consistent with previous data. Findings indicated that hospitalization rates varied between the different age groups. Although children 6-14 weeks of age had the lowest rate of intussusception hospitalization among all age groups studied, this rate significantly increased post vaccination. Rates of hospitalization in all of the other age groups had no significant increase. This study was limited by the fact that vaccination data was not available in the databased used. In addition, this study used ICD-9 codes to identify intussusception hospitalizations and no attempts were made to confirm the diagnosis. This study was restricted to 26 states, thus, possibly limiting its generalizability. Furthermore, cases managed in the outpatient setting were not captured by this data. Nonetheless, despite these findings, providers should keep in mind that given the magnitude of the decreased rates of rotavirus before and after the development of the vaccine, the benefits far exceed the small increased risk of intussusception.

Click to read the study, published today in Pediatrics 

Relevant Reading: Intussusception, Rotavirus, and Oral Vaccines: Summary of a Workshop

In-Depth [ecologic analysis]: Using the State Inpatient Databases (SID), which captures inpatient data from community hospitals at participating sites in 26 states, data was extracted from 2000 to 2013. Trends in intussusception rates and hospitalizations were observed over time and analyzed further by age groups. Rates of intussusception in 2004 before the vaccine was introduced ranged from 33.9 to 37.2 per 100000 children less than 12 months of age between 2003 and 2005. After introduction of the vaccine, rates of intussusception were significantly elevated in 2007 and 2010, 40.7 per 100000 children (RR 1.13, 95% CI: 1.07–1.20) and 40.3 per 100000 children (RR 1.12, 95%CI: 1.06-1.20), respectively. Trends in hospitalizations varied from group to group. For example, in the pre-vaccine era from 2000 to 2005, the average rate of hospitalization from intussusception was 15.0 per 100000 children ages 6 to 14 weeks. In contrast, in the post-vaccine years, this group’s hospitalization rate was significantly elevated by 25% to 50%. Similarly, in the 8-11 week age group, hospitalization rates were significantly elevated by 46% to 101% (range: 16.7-22.9 per 100000), except in 2011 and 2013, where there was no significant increase. For children aged 15 to 24 weeks, hospitalization rates pre and post-vaccine introduction were similar.

Image: PD

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