Rotavirus vaccine achieves strong results in Bangladesh Clinical Trial

April 25, 2007 by PATH

Infectious diseases
Findings add evidence for developing country use of rotavirus vaccines

Contact:
Eileen Quinn, 202.454.5005, equinn@path.org 

LISBON, April 25, 2007—Infants who received a new oral rotavirus vaccine through a clinical trial in Bangladesh achieved significant immune responses, the study’s lead investigator announced today at the Vaccines for Enteric Diseases conference in Lisbon, Portugal. In the study conducted at the International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B) and co-sponsored by the PATH Rotavirus Vaccine Program and GlaxoSmithKline (GSK), 57-67% of the children who received theRotarix™ vaccine manufactured by GSK developed an immune response.

Rotavirus is the most common cause of severe diarrhea in young children worldwide. According to updated figures released by the World Health Organization at this week’s conference, nearly one-third of all diarrhea-related deaths among children below age five are attributable to rotavirus. The vast majority of rotavirus mortality—nearly 85 percent—occurs in Asia and Africa.

Because rotavirus is a particularly resilient virus and is not responsive to traditional measures used to control diarrheal disease, immunization is the most effective strategy to reduce its incidence and severity. Results from initial studies in the US, Latin America, and Europe prompted the rapid introduction of rotavirus vaccines in several industrialized countries beginning in early 2006.

“The vigorous immune response achieved in the clinical trial is a very promising result,” noted Dr. K. Zaman, Principal Investigator at ICCDR,B for the study. “Equally important, we found that whenRotarix™ was given with the oral polio vaccines, it did not lower the polio immune response.” 

 “These data are important for accelerating the availability of rotavirus vaccines to the world’s poorest countries, where the disease takes its greatest toll,” said Dr. John Wecker, Director of the PATH Rotavirus Vaccine Program. “These results combined with the results from large-scale clinical trials already underway are creating the evidence that developing countries need to understand the potential impact of rotavirus vaccines.”

“Among Bangladeshi infants, Rotarix™ demonstrated a strong immunogenicity profile comparable to what was previously observed in different regions of the world like Latin America and Europe, where the vaccine produces high protection rates against rotavirus disease,” said Dr. Sanjoy Datta, Director Clinical R & D GSK Biologicals, South Asia. “The study results from Bangladesh show that the vaccine is immunogenic in settings with impoverished populations.”

This is a particularly important finding, in that the performance of oral vaccines can vary in different regions of the world. The World Health Organization’s Strategic Advisory Group of Experts, has called for studies on the safety and efficacy of new rotavirus vaccines among infants in Asia and Africa as a prerequisite to a recommendation on their global use. The advisory group also noted the importance of studying the co-administration of rotavirus vaccines with those provided through routine immunization programs, particularly the oral polio vaccine. The trial results show that the oral rotavirus vaccine may be administered concomitantly with the oral polio vaccine.

PATH’s Rotavirus Vaccine Program is working in partnership with GSK and Merck & Co., Inc. to evaluate the safety and efficacy of their respective rotavirus vaccines among impoverished populations in developing countries. A large-scale efficacy study of GSK’s Rotarix™ vaccine is ongoing in South Africa and Malawi. A similar study of Merck’s RotaTeq® vaccine began in Bangladesh in March, and enrollment will begin later this year in Mali, Ghana, Kenya, and Vietnam.

Notes:

  • The clinical trial was conducted by the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), an international health research institution with extensive experience conducting hospital-and community-based clinical research in diarrheal diseases.
  • The Phase II, double-blind, randomized, placebo-controlled study of 300 children was conducted June 2005 through January 2006 of the GSK Rotarix™ 2-dose vaccine.