In August of 2006, the Advisory Committee on Immunization Practices (ACIP) recommended
RotaTeq for routine vaccination of US infants. The hypothesis tested in the present study is that
rotavirus vaccines are associated with an increased risk of
intussusception adverse events (AEs) characterized by an onset in a biologically plausible a priori identified temporal period post-vaccination (days 3 to 7).
MATERIAL/METHODS: Following
RotaTeq vaccination, a significantly (p<0.001) higher percentage of AEs were classified as serious, permanently disabling, resulted in hospitalizations, or were life-threatening among
intussusception AEs in comparison to the total AE reports (removing
intussusception AE reports) submitted to VAERS. A significantly greater portion of
intussusception AEs in comparison to the portion of total AE reports (removing
intussusception AE reports) were reported to VAERS in the onset interval from 3 to 7 days post-
RotaTeq vaccination than within the onset interval from 1 to 2 days post-
RotaTeq vaccination (78.7% vs. 29.1%, risk ratio=2.7, 95% CI=2.4-3.0, p<0.0001). It was assumed in our onset time-trend analyses of the distribution of AEs following Rota-Teq vaccination that the AE's should be equally likely to be reported with an onset time for each day, from 1 to 9 days post-vaccination or, alternatively, should follow similar daily proportions as observed for total AEs reports (removing
intussusception AE reports). Results of this onset time-trend analyses of the distribution of
intussusception AEs reported to VAERS following Rota-Teq vaccination revealed significant differences (p<0.001) from our expectations. Consistent and similarly remarkable trends were observed for
intussusception AE reports associated with RotaShield
vaccine.
CONCLUSIONS: