点击显示 收起
Feb. 22, 2006 -- The CDC's Advisory Committee on Immunization Practices (ACIP) has voted to recommend a newly licensed vaccine to protect against rotavirus.
Rotavirus is a viral infection that can cause severe diarrhea, vomiting, fever, and dehydration (gastroenteritis) in infants and young children. While rotavirus isn't responsible for all cases of diarrhea, it's the No. 1 cause of kids' severe diarrhea.
The new vaccine, RotaTeq, is the only approved in the U.S. for prevention of rotavirus gastroenteritis. It was licensed by the FDA in early February.
A previous rotavirus vaccine was withdrawn from the market in 1999 due to risk of intussusception, a rare cause of intestinal obstruction. The new vaccine hasn't shown a higher risk of intussusception in studies and will be closely monitored by the CDC and FDA.
Vaccine Recommendations
The ACIP recommends that infants receive three doses of the oral vaccine at 2, 4, and 6 months of age. Children should receive the first dose of the vaccine by 12 weeks of age and should receive all doses of the vaccine by 32 weeks of age.
"There is insufficient data on safety and efficacy outside of these age ranges," states a CDC news release.
The ACIP's recommendations become the CDC's recommendations once they are accepted by the CDC director and the U.S. secretary of Health and Human Services, and they are published in the CDC's Morbidity and Mortality Weekly Report.
CDC's Comments
In a news release, Anne Schuchat, MD, director of the CDC's National Immunization Program, commented on rotavirus and the new vaccine.
"Rotavirus is the leading cause of severe gastroenteritis in infants and young children worldwide," Schuchat says.
"Nearly every child in the United States is infected with rotavirus by age 5 and most will develop gastroenteritis, leading to a large number of physician visits, emergency room visits, and hospitalizations, with a few deaths," she continues.
"Therefore, this vaccine will help reduce one of our most common and potentially severe childhood illnesses."
In the U.S., rotavirus annually causes:
In developing countries, rotavirus is a major cause of childhood deaths, with an annual death toll of more than half a million children younger than 5 years.
The new rotavirus vaccine will not prevent gastroenteritis caused by other viruses, but it's "very effective against rotavirus disease," states the CDC.
Studies indicate the vaccine will prevent about 74% of all rotavirus cases and about 98% of the most severe cases, including 96% of rotavirus cases requiring hospitalization. In trials, the vaccine prevented 59% of all causes of gastroenteritis hospitalizations, which highlights the important role of rotavirus in severe childhood gastroenteritis, according to the CDC.
No Sign of Intestinal Problem
In 1999, a rotavirus vaccine called RotaShield was withdrawn from the market after it was found to be associated with a rare cause of bowel obstruction called intussusception.
The risk of intussusception for RotaTeq, the new vaccine, was evaluated in a large-scale trial of more than 70,000 children. In that study, no association was found between the RotaTeq vaccine and an increased risk of intussusception, and RotaTeq did not cause fever to the extent caused by RotaShield, states the CDC.
"This is a different vaccine than the vaccine removed from the market because of problems with bowel obstructions," says Schuchat. "It is made differently and was not associated with intussusception in a large clinical trial.
"Nevertheless, we will continue to very closely monitor this vaccine to ensure there are no problems," Schuchat continues. "At the same time, it's important to remember that the known benefits of the vaccine far outweigh any known risks."
Close Monitoring
The CDC will conduct a large study to rapidly detect any association between RotaTeq and intussusception as well as other potential adverse events through its Vaccine Safety Datalink Program that evaluates vaccine safety in approximately 90,000 infants every year.
The CDC and FDA will also regularly monitor reports of intussusception and other serious adverse events reported to the Vaccine Adverse Event Reporting System (VAERS).
RotaTeq's marketer, Merck and Company, has also committed to conducting a post-licensure study of approximately 44,000 children. In addition, the manufacturer will report cases of intussusception to the FDA within 15 days of receiving them. Merck is a WebMD sponsor.
SOURCES: News release, CDC. WebMD Medical News: