Approximately 4.5 million cases of gastroenteritis due to rotavirus infection occur each year in the European Union among children under the age of 5. This makes rotavirus the most frequent vaccine-preventable illness among young children in the EU and translates into one child out of five who visit a physician and one of fifty being hospitalized annually.
"We have long since recognized the need for a safe and effective rotavirus vaccine and the significant impact that it can have throughout the world, says David Bernstein, M.D., director of the division of Infectious Diseases at Cincinnati Children's and one of the key developers of Rotarix™. "Because of dehydration due to rotavirus infections, more than 600,000 infants and young children die each year. While most deaths are in developing countries, hospitalizations in Europe are common."
Rotavirus infection is a leading cause of severe diarrhea in infants and young children throughout the world, with virtually every child exposed by the age of 5. In addition to diarrhea, it is usually associated with fever and vomiting often lasting for several days. There is no specific treatment for rotavirus. To prevent dehydration, physicians may recommend an oral rehydration fluid, especially if diarrhea lasts longer than a few days.
Richard Ward, Ph.D., a scientist at Cincinnati Children's, originally isolated the human rotavirus strain in 1988. Dr. Ward developed the strain into a live, orally-deliverable vaccine candidate under a licensure agreement with Avant Immunotherapeutics, Inc. After a highly successful but small Phase II efficacy trial led by Dr. Bernstein and Dr. Ward, Avant sublicensed this vaccine candidate to GSK in 1997. The trial results, published in The Lancet in 1999, showed the vaccine to be 89 percent effective in preventing rotavirus disease in infants.
A new study published in January 2006 in The New England Journal of Medicine showed that RotarixTM protected 85 percent of infants from rotavirus disease and was 100 percent effective against more severe rotavirus episodes in the first year of life.
Rotarix™ first received approval in Mexico in 2004. Since then, 30 licenses have been granted worldwide, including 15 Latin American countries, the Philippines, Thailand and Singapore. There are plans to file in the United States, where discussions are ongoing with the FDA.
"The use of a weakened human strain compared to animal rotaviruses has proven to induce better immune responses because it is more closely related to circulating human rotavirus strains," says Dr. Ward. "It also appears to be safe and has not produced any cases of intussusception, as did the Rotashield vaccine, which was withdrawn from the market in 1999. Rotashield was produced from monkey RRV strain of rotavirus."
In February 2006, the FDA approved a rotavirus vaccine sold by Merck & Co. of Whitehouse Station, N.J., under the brand name RotaTeq. Merck, at the direction of the Food and Drug Administration, conducted a test of RotaTeq involving 68,038 babies in 11 countries. GSK conducted a test nearly as large as Merck's in 12 countries.
Those two tests are the largest vaccine trials ever conducted by drug companies, and the largest by any sponsor since the March of Dimes polio clinical trials in the 1950s that led to the eradication of polio in the Western world. Cincinnati Children's was a driving force in those trials as well. The oral polio vaccine was developed by Dr. Albert Sabin at Cincinnati Children's in the 1950s.
Cincinnati Children's Hospital Medical Center is a 475-bed institution devoted to bringing the world the joy of healthier kids. Cincinnati Children's is dedicated to transforming the way health care is delivered by providing care that is timely, efficient, effective, family-centered, equitable and safe. Cincinnati Children's ranks third nationally among all pediatric centers in research grants from the National Institutes of Health. It is a teaching affiliate of the University of Cincinnati College of Medicine. The Cincinnati Children's vision is to be the leader in improving child health. Additional information can be found at www.cincinnatichildrens.org.