Rotavirus is a nasty virus. It is the most common cause of severe diarrhea among infants and young children. It is one of several viruses that cause infections often called the stomach flu despite having no relation to influenza.
Rotavirus is usually an easily managed disease of childhood, but worldwide more than 500,000 children under five years of age still die from Rotavirus infection each year and almost two million more become severely ill.
In an effort to prevent this virus in 1998, the first Rotavirus vaccine was created. However, the manufacturer withdrew it from the market in 1999 after it was discovered the vaccine may have contributed to an increased risk for intussusception, a type of bowel obstruction, in 1 out of every 12,000 vaccinated infants.
It took another 7 years before an alternative Rotavirus vaccine was licensed in the US. However, it looks as if the problems may be the same.
In a recent study that is being discussed at The Pediatric Super Site, it states, “One of the currently licensed rotavirus vaccines was associated with a short-term risk for intussusception, according to results of a study published online this week.”
The risk for intussusception was seen in approximately 1 of every 51,000 to 68,000 vaccinated infants, but the incidence of morbidity and mortality associated with rotavirus was greatly reduced and the benefits of the vaccine far exceeded the risks, states the report.
Intussusception occurs when one portion of the bowel slides into the next, much like the pieces of a telescope. When this occurs, the walls of the intestines press against one another creating a blockage in the bowel. In turn, this leads to swelling, inflammation and decreased blood flow to where the intestines are creating a block.
Harry B. Greenberg, MD, senior associate dean for research at the Stanford University School of Medicine, wrote a commentary to accompany the study and said this is the second study to suggest an intussusception risk in the two commercially available rotavirus vaccines.
“The vaccines’ pluses so outnumber the minuses that it’s almost immaterial to talk about the minuses,” Greenberg said. “In places like the United States or Western Europe, the new vaccines substantially reduce hospitalizations and morbidity. They save hospital costs plus the cost of work lost to parents who have to bring their child to the doctor or have the child hospitalized.”
In the current study, researchers identified 615 case patients — 285 in Mexico and 330 in Brazil — and 2,050 controls. They noted an “increased risk of intussusception 1 to 7 days after the first dose among infants in Mexico with the use of both the case-series method and the case–control method” after the children were administered Rotarix® (RV1, GlaxoSmithKline). There was no significant risk after the first dose in children in Brazil, but some increased risk 1 to 7 days after vaccination.
“However, RV1 prevented approximately 80,000 hospitalizations and 1,300 deaths from diarrhea each year in these two countries,” the researchers wrote.
Greenberg said in his editorial these two studies were taken with previous data from the older rotavirus vaccine, RotaShield® (Wyeth), which was pulled from shelves. The studies suggest that natural rotavirus infection itself probably causes intussusception at some low frequency.
Further research is obviously needed in order to adequately decide if in fact the vaccine is a greater option than being exposed to the virus itself.