Risk of Intussusception After Rotavirus Vaccination.

backgroundIn 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.

methodsWe 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.

resultsOf 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.

conclusionRV 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).