In 1996, the vaccine RotaShield, made by Wyeth for the rotavirus was withdrawn from the U.S. market following similar symptoms; a condition called intussusception. However, intussusception can also occur spontaneously in the absence of a vaccination.
Yet, in the abundance of caution, the FDA has pulled the vaccine after 28 new cases of intussusception were reported in children who had been vaccinated. The affected 16 infants required intestinal surgery but so far none of the incidents have been fatal.
The FDA also plans to encourage the reporting of additional cases of intestinal twisting or blockage to analyze the undermining risks that may find out why the three-shot vaccine series is possibly causing the illness.
However, Dr. Michelle Goveia, medical director for pediatric medical affairs at the vaccine's manufacturer, Merck and Co. says, "It looks like [the number of cases reported are] the natural background rate that we are seeing."
Yet FDA spokeswoman Karen Riley maintains that an adverse reaction to the vaccine is a serious, "life-threatening adverse event that is being seen at an expected level post marketing. But because it is so serious, we asked the company to change the label." The FDA also wants the vaccine's label to mention the risk of intussusception.
However, according to AFX news agency, GlaxoSmithKline (GSK) said its Rotarix vaccine for rotavirus gastroenteritis has been awarded prequalification status by the World Health Organization (WHO). Gastroenteritis has been the most common cause of severe diarrhea in infants all over the world.
GSK said it is the first such clearance awarded to a rotavirus gastroenteritis vaccine. According to the FDA, about 3.5 million doses of the Merck vaccine have been distributed in the U.S., though not all have been used.
Rotavirus most often infects infants and young children, and in children ages 3 months to 2 years, is one of the most common causes of diarrhea. In the United States, it leads to outbreaks of diarrhea during the winter and spring months. It is particularly a problem in child-care centers and children's hospitals. Almost all children have had a rotavirus infection by the time they are 5 years old.
The diarrhea caused by rotavirus results in more than half a million deaths worldwide every year.
