WASHINGTON (Reuters) - A second oral vaccine to prevent a leading cause of severe diarrhea in infants won approval from U.S. health officials on Thursday.
The GlaxoSmithKline Plc vaccine Rotarix fights infection with the rotavirus, which causes about 55,000 hospitalizations in U.S. children each year and kills more than 600,000 children worldwide, mostly in developing countries.
Rotarix already is approved in more than 100 other countries throughout the world. The vaccine competes with Merck & Co Inc’s rotavirus vaccine called RotaTeq.
Without vaccination, nearly every child in the United States likely would be infected at least once with rotavirus by age five, the Food and Drug Administration said.
In studies of more than 24,000 infants, Rotarix prevented severe and mild cases of rotavirus-caused diarrhea and vomiting during the first two years of life.
“This vaccine provides another option to combat and reduce a potentially severe illness that affects so many children,” Dr. Jesse Goodman, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement announcing the Rotarix approval.
The most common reactions reported during clinical trials were fussiness, irritability, cough, runny nose, fever, loss of appetite and vomiting, the FDA said.
An earlier oral rotavirus vaccine sold by Wyeth was pulled from the market in 1999 after it was linked to a rare, life-threatening type of bowel obstruction known as intussusception.
In a Glaxo study of more than 63,000 infants, there was no increase in the problem compared with a placebo.
Higher rates of convulsion and pneumonia-related deaths were seen in Rotarix patients in that study but not in other Glaxo trials.
“Although the FDA has concluded that the available data do not establish that these events are related to the vaccine, the agency has requested the manufacturer to conduct post-marketing safety studies involving more than 40,000 infants to provide additional safety information,” the FDA said.
Glaxo said Rotarix “will offer protection against the most commonly circulating rotavirus types in the U.S. and allow infants to complete the vaccination series by four months of age.”
Rotarix, which is a liquid, is given in two doses to infants from six to 24 weeks of age, the FDA said.
Merck’s RotaTeq vaccine is administered in three doses from ages six weeks to 32 weeks.
Sales of Rotarix were $182 million in 2007 and are expected to rise with approval in the large U.S. market. The vaccine will be commercially available in the United States in the second half of the year, Glaxo said.
Also on Thursday, researchers reported that Rotarix provided protection for up to two years in a study of infants from 10 Latin American countries.
The Glaxo-funded trial of more than 15,000 infants found severe diarrhea from rotavirus in 0.4 percent of children given the vaccine, compared with 2.3 percent in the placebo group. Results were published in the Lancet medical journal.
The arrival of a new generation of oral vaccines against the disease has been welcomed by health-care workers, but some experts caution against assuming the vaccines will work equally well in all countries.
In a commentary in the Lancet, Australian pediatric experts Keith Grimwood and Carl Kirkwood noted Rotarix was more effective in European trials than in middle-income Latin American countries.
The World Health Organization “is awaiting efficacy data from low-income countries of Africa and Asia, where much greater strain diversity exists and where 413,000 deaths occur every year compared with 15,000 in Latin America and 200 in Europe,” Grimwood and Kirkwood wrote.
Editing by Tim Dobbyn and Braden Reddall