Risk of intussusception after rotavirus vaccination: a meta-analysis

Background: Rotavirus vaccines (RVs) are commonly used in children in the clinical setting. However, increasing concerns on its association with intussusception have been reported, with controversial outcomes. Methods: We conducted a comprehensive literature search of Medline, Pubmed and Embase. Children less than one year old vaccinated with RV1 and/or RV5 rotavirus vaccine were used as inclusion criteria. Results: 8 studies were included in the meta-analysis. Vaccines under studies were RV1 and RV5. Overall, there was an association between immunization and risk for developing intussusception: the overall estimate of relative risk (RR) of intussusception during the 7 days after dose 1 and/or dose 2 of RV1 and/or RV5 respectively was: 5.31 (95% confidence interval (CI): 3.22-8.74), P < 0.0001; 1.93 (95% CI: 1.43-2.61), P < 0.0001; 4.56 (95% CI: 3.05-6.82), P < 0.0001; 1.69 (95% CI: 1.18-2.40), P = 0.004. Sensitivity analysis showed that the significances of pooled estimates of RR stay unchanged when a single study was excluded for both vaccines and two doses. Conclusions: There is a significant increased risk of developing intussusception after immunization with RV during the first 7 days. Similarly increased risk pattern of intussusception for both vaccines are found where post-dose 1 has more risk compared to post-dose 2.