The vaccine, taken orally in three doses when babies are between 6 weeks old and 32 weeks old, is intended to protect infants against rotavirus infection.
Every year, about 55,000 U.S. children are hospitalized due to rotavirus, and more than 600,000 children worldwide die of diarrhea caused by rotavirus, according to the CDC.
Few children in the U.S. die of rotavirus. Most deaths occur in developing countries due to problems with the water supply.
The FDA's approval doesn't put RotaTeq on the CDC's schedule of recommended vaccines. The CDC's Advisory Committee on Immunization Practices is already evaluating RotaTeq and will discuss the vaccine at a meeting later this month, says the FDA's Jesse Goodman, MD, MPH.
Goodman directs the FDA's Center for Biologics Evaluation and Research. He spoke to reporters about RotaTeq in a conference call.
No Sign of Intestinal Problem
In clinical trials of about 72,000 healthy infants in the U.S. and other countries, RotaTeq prevented 74% of all rotavirus diarrhea cases and 98% of the severe cases. The vaccine also prevented about 96% of rotavirus-related hospitalizations.
RotaTeq will get "aggressive" safety monitoring by the vaccine's maker and the CDC, Goodman says.
Unlike an earlier rotarvirus vaccine that had been pulled from the market, RotaTeq hasn't been found to raise the risk of a serious and potentially fatal condition called intussusception.
In intussusception, the intestine folds into itself like a telescope. The problem can cause intestinal blockage due to swelling and inflammation at the intussusception site. Intussussception is usually seen in very young children -- those less than 2 years old -- and is rare in adults.
In clinical trials, RotaTeq wasn't linked to an increased risk of intussusception. However, "no medicine can ever be guaranteed to be absolutely safe, even vaccines, which are among our safest medicines," Goodman says.
He suggests that parents and doctors discuss the vaccine and "look carefully" at the CDC's discussions about RotaTeq. "I think those will be informative," Goodman says.
"Sometimes when a medicine is used in much larger numbers of individuals, you might detect an adverse event that wasn't seen in the studies before licensure, even in very large numbers like this," Goodman says.
"I think we have a lot of data here that are reassuring. That's the way I would put it," Goodman says.
"But people would need to consider that [the studies are] not conclusive that this side effect could not potentially occur and just not have been noticed, or occur at a much lower incidence, or maybe in a different manner. So this is why we put into place what I would say is an extremely aggressive program to try to get as much information about the vaccine in its early period of use as possible," Goodman says.
In clinical trials, reports of diarrhea, vomiting, ear infection, runny nose, sore throat, wheezing, and coughing were more common among babies given RotaTeq than a fake vaccine (placebo), according to an FDA news release.
Other Vaccines in the Works
Other rotavirus vaccines are in the works in the U.S. and other countries but have not been approved by the FDA, Goodman notes.
RotaTeq is one of two rotavirus vaccines that were recently called "promising" in The New England Journal of Medicine. The other vaccine, called Rotarix, hasn't been FDA-approved.
An editorial in the journal also stated that "hundreds of thousands of children will need to be immunized before a clean bill of health can be given to these vaccines. The editorialists included the CDC's Roger Glass, MD, PhD.
RotaTeq is made by Merck. Rotarix is made by GlaxoSmithKline. GlaxoSmithKline and Merck are WebMD sponsors.