Post-marketing monitoring of intussusception after rotavirus vaccination in Japan.

Abstract

PURPOSE:

Rotarix(TM) was launched in November 2011 in Japan to prevent rotavirus gastroenteritis. Some studies suggest that Rotarix(TM) may have a temporal association with a risk of intussusception (IS). We assessed a possible association between IS and Rotarix(TM) vaccination in Japan.

METHODS:

All IS cases spontaneously reported post-vaccination (Brighton collaboration levels 1, 2, and 3) were extracted from the GlaxoSmithKline spontaneous report database on the 11th of January 2013. Expected numbers of IS cases were estimated using the number of vaccine doses distributed and the Japanese incidence rate of IS stratified by month of age. The observed versus expected analysis considered the IS cases for each risk period (7 and 30 days post-vaccination) and for each vaccine dose (two doses).

RESULTS:

Before January 2013, approximately 601 000 Rotarix(TM) doses were distributed in Japan. For a risk period of 7 days post-dose 1 and post-dose 2, 10 and five IS cases were observed, whereas 3.4 and 7.6 were expected, providing an observed-to-expected ratio of 2.96 (95% confidence interval [CI]: 1.42; 5.45) and 0.66 (95% CI: 0.21; 1.53), respectively. For a risk period of 30 days post-dose 1 and post-dose 2, 14 and eight cases were observed, whereas 14.5 and 32.7 were expected, providing an observed-to-expected ratio of 0.97 (95% CI: 0.53; 1.62) and 0.24 (95% CI: 0.11; 0.48), respectively.

CONCLUSION:

A statistically significant excess of IS cases was observed within 7 days post-dose 1, but not post-dose 2. These results are consistent with previous observations in large post-marketing safety studies in other world regions.

• Authors: Vincent Bauchau, Lionel Van Holle, Olivia Mahaux, Katsiaryna Holl, Keiji Sugiyama, Hubert Buyse
• Journal: Pharmacoepidemiology and drug safety (Pharmacoepidemiol Drug Saf) Vol. 24 Issue 7 Pg. 765-70 (Jul 2015) ISSN: 1099-1557 [Electronic] England
• PMID: 26013569 (Publication Type: Journal Article)
• Copyright: © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons, Ltd.

Chemical References

• RIX4414 vaccine
• Rotavirus Vaccines
• Vaccines, Attenuated

Topics

• Drug-Related Side Effects and Adverse Reactions (epidemiology, etiology)
• Humans
• Incidence
• Intussusception (chemically induced, epidemiology)
• Japan (epidemiology)
• Product Surveillance, Postmarketing (statistics & numerical data)
• Risk Assessment
• Rotavirus Vaccines (administration & dosage, adverse effects)
• Vaccines, Attenuated (administration & dosage, adverse effects)