TUESDAY, Jan. 14 (HealthDay News) -- Newer vaccines that protect
against rotavirus have lower risks of bowel obstruction for infants
than a previous vaccine did, two new studies suggest.
"We would call it a small increased risk," said W. Katherine Yih, a lecturer at Harvard Medical School who led one of the studies to examine the risks.
Rotavirus can cause severe gastroenteritis in infants, requiring
hospitalization. The condition involves inflammation of the stomach
and intestines, and its main symptoms are watery diarrhea and
vomiting, according to the U.S. Centers for Disease Control and
The benefits of the rotavirus vaccine -- preventing the viral
infection and hospitalization of infants -- outweigh the risk of
the bowel complication, Yih said. "In a typical five-year period
following a typical year for births, the vaccine will probably
prevent more than 50,000 hospitalizations."
Yih's team analyzed the bowel risk linked with one of the two
rotavirus vaccines now on the market. She looked at RotaTeq,
licensed in 2006. A team of researchers from the CDC and other
institutions analyzed the risk linked with RotaTeq and another
vaccine on the market, Rotarix, licensed in 2008.
Both studies are published online Jan. 14 in the
New England Journal of Medicine.
A previous vaccine, RotaShield, was withdrawn from the U.S.
market in 1999 due to the increased risk of the bowel problem,
known as intussusception.
The RotaShield vaccine carried a risk of about one or two cases
of bowel obstruction per 10,000 vaccine recipients, Yih noted. In
her study, she looked at nearly 1.3 million doses of RotaTeq and
found the vaccine is linked with about 1.5 cases of the bowel
problem per 100,000 first doses. That is about one-tenth of the
risk of RotaShield, she said.
As for Rotarix, there were not enough doses in her study to
analyze risk, Yih added.
In the other study, researcher Eric Weintraub, of the CDC's
Immunization Safety Office, and colleagues did not find an
increased risk of bowel problems with RotaTeq. They did find that
receiving two doses of the Rotarix vaccine was linked to 5.3 cases
of bowel obstruction for every 100,000 infants vaccinated.
Both vaccines are given by mouth. RotaTeq requires three doses,
given between 6 weeks and 32 weeks of age. Rotarix requires two
doses, given between 6 weeks and 23 weeks.
The risks must be weighed against the benefits, Yih said. "The
vaccine is very effective in preventing severe diarrhea," she
Dr. Roya Samuels, a pediatrician at Cohen Children's Medical
Center, in New Hyde Park, N.Y., said that more research is needed
to pinpoint exactly what the risk is.
These findings are not a reason to bypass or decline the
vaccine, she said, also citing the benefits of preventing the viral
"If I were the parent of an infant, I would not decline it," researcher Yih said of the vaccine. "I'd do it for the protection of my child, and those who can't receive it due to being immunocompromised." Among those with weakened immune systems, she said, are children on certain cancer treatments.
There's no way to know if some children are more prone to the
bowel problem after getting the vaccine, Samuels said. Yih found
the problem more likely after the first dose of RotaTeq.
Parents can be aware of possible symptoms, Samuels said. "If you
notice your child in distress, pulling his knees up to the chest,
with severe colic or blood in the stools -- any of those -- within
seven days of administration of the rotavirus vaccine, [it] would
warrant a trip to the emergency room," she said.
To learn more about rotavirus, see the
U.S. Centers for Disease Control and Prevention.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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