ROTATEQ® Substantially Reduced Rotavirus-related Hospitalizations and Emergency Room Visits Combined in New U.S. Observational Study

Business Wire, Oct 25, 2008

WHITEHOUSE STATION, N.J. -- ROTATEQ([R]) (rotavirus vaccine, live, oral, pentavalent) reduced rotavirus-related hospitalizations and emergency room (ER) visits combined by 100 percent during the 2007 and 2008 rotavirus seasons (January through May of each year) in an observational study in the United States. The large, national, post-licensure observational study was based on a review of health insurance claims data from approximately 61,000 infants in the U.S. These data on ROTATEQ, the pentavalent rotavirus vaccine from Merck & Co., Inc. that helps prevent rotavirus gastroenteritis in infants and children, were presented at the 48th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC)/Infectious Diseases Society of America (IDSA) 46th Annual Meeting in Washington, D.C.

ROTATEQ is an oral, pentavalent, ready-to-use vaccine that helps prevent rotavirus gastroenteritis caused by the serotypes G1, G2, G3 and G4 when administered as a three-dose series to infants between the ages of 6 to 32 weeks. ROTATEQ may not protect all vaccine recipients against rotavirus.

This is the first national study to evaluate the effectiveness of ROTATEQ in routine clinical practice. The data are consistent with the results seen in the landmark Rotavirus Efficacy and Safety Trial (REST), in which ROTATEQ reduced rotavirus-related hospitalizations and ER visits caused by serotypes G1-G4 by approximately 95 percent. In a separate post-hoc analysis, ROTATEQ reduced rotavirus-related hospitalizations and ER visits caused by serotype G9,P[8] by 100 percent up to two years post-vaccination (n=68,038).

"These data add to the growing body of evidence showing the impact of ROTATEQ on rotavirus disease in the United States. As a practicing clinician, I am encouraged that this study suggests that when the vaccine is incorporated into the standard childhood immunization schedule and administered routinely, we would expect to see fewer infants admitted to hospitals and emergency rooms due to rotavirus," said Mary Allen Staat, M.D., M.P.H., professor of Pediatrics at the University of Cincinnati, and a member of the Infectious Disease Division at Cincinnati Children's Hospital Medical Center.

Earlier this year, in June 2008, the U.S. Centers for Disease Control and Prevention (CDC) issued a preliminary report on rotavirus disease in the U.S. based on data from CDC surveillance systems. The report showed that in the rotavirus season from November 2007 through May 2008, compared to previous years, there was a marked reduction in the number of positive laboratory tests for rotavirus gastroenteritis and associated medical care (hospitalizations, emergency room and clinic visits). An update from the CDC and seven other independent scientific presentations on the decline in rotavirus disease burden following introduction of ROTATEQ are also part of this scientific meeting.

The post-licensure vaccine effectiveness study assessed the effectiveness of ROTATEQ by analyzing data from a large, national health insurance claims database. For the analysis, the frequency of hospitalizations, ER visits and physician office visits associated with a physician diagnosis for rotavirus were compared between two groups: 33,135 infants who received three doses of ROTATEQ and 27,954 infants who had not been vaccinated with ROTATEQ, but who had received other routine childhood vaccines. The study was a retrospective analysis of prospectively collected data conducted during two rotavirus seasons. The study design did not rely on historical comparisons; rather it compared those who received ROTATEQ with controls of a similar age who did not receive ROTATEQ, allowing the analysis to generate an estimate of vaccine effectiveness during routine vaccination with ROTATEQ. This is a non-randomized, claims-based observational study. In the study, the diagnosis of rotavirus did not include laboratory confirmation and was only based on the use of physician diagnosis.

The data showed that ROTATEQ reduced the combined incidence of hospitalizations and ER visits related to rotavirus gastroenteritis by 100 percent (0.0 vs. 3.7 events per 1,000 patient-years, 95 percent CI 86 -100), with hospitalizations reduced by 100 percent (0.0 vs. 3.5 hospitalizations per 1,000 patient-years, 95 percent CI 85 - 100) and ER visits by 100 percent (0.0 vs. 0.2 ER visits per 1,000 patient-years, 95 percent CI <0 -100).

In this study, ROTATEQ also reduced the medical care costs associated with rotavirus related hospitalizations and ER visits by 100 percent ($0.0 versus $12,021 per 1,000 patient-years, 95 percent CI 100 -100). Reduction in medical care costs were estimated by comparing total costs for the number of days spent in the hospital or ER that were associated with rotavirus, for each group.

"These data demonstrate the importance of vaccination programs and are a testament to the public health benefits provided by vaccines like ROTATEQ. Merck is committed to the development and implementation of vaccines, and we are pleased that ROTATEQ is helping to reduce the burden of rotavirus gastroenteritis," said Mark Feinberg, M.D., Ph.D., vice president of Medical Affairs and Policy, Merck Vaccines and Infectious Diseases.