In 1999,
the rotavirus vaccine RotaShield was pulled from the market after being
linked to an increase in intussusception in infants. Intussusception is
a dangerous twisting of the intestines that can often require intestinal
surgery. On February 13, 2007, the government issued a warning that
there have been 28 new cases of intussusception recently reported. It
is not known if the new rotavirus vaccine RotaTeq may be the cause of
this.
The
rotavirus causes diarrhea in children and newborns. In the United
States, it has infected over 2.7 million children under five years of
age. Of these children, 70,000 were hospitalized, with a range of 20 to
70 deaths each year caused by the rotavirus.
RotaTeq
was approved by the FDA in 2006 as a new vaccination series against the
rotavirus. Tests indicated there were no increases in intussusception
in the 70,000 children that were followed after receiving the injection
series. Follow-up studies are continuing on these children to determine
if there are long term side effects from RotaTeq.
The FDA
has noted that the current 28 new cases do not exceed the natural
instances of intussusception expected yearly. Dr. Michelle Goveia, the
medical director for pediatric medical affairs of Merck & Co. Inc. has
stated these numbers indicated a natural background rate for
intussusception.
Karen
Riley, an FDA spokeswoman, backs this possibility, stating, "It's a
known serious, life-threatening adverse event that is being seen at an
expected level of post-marketing." She continued, "But because it is so
serious, we asked the company to change the label." The FDA is asking
Merck to mention these cases of intussusception on the label of RotaTeq.
This will encourage further possible cases to be reported, giving both
the FDA and Merck more information to study regarding any new
intussusception cases.