Risk of intussusception after rotavirus vaccine

A very low risk of intussusception exists after rotavirus vaccination, usually 3 to 6 days after the first vaccine dose, but the benefits of vaccination far outweigh the risks.

A recently published study looked at the number of incidents of intussusception reported to the US Vaccine Adverse Event Reporting System after vaccination with either RotaTeq (RV5) during the period February 2006 through April 2012 or Rotarix (RV1) during the period April 2008 through April 2012.

The investigators found that most intussusception events occurred 3 to 6 days after dose 1 of either vaccine, but that more occurred following dose 1 of RV5 than dose 1 of RV1.

Looking at all 3 doses of vaccine, they calculated the excess risk of intussusception to be about 0.8 cases per 100,000 vaccines. This translates to 33 excess intussusception events annually after rotavirus vaccination, which is substantially lower than the number of diarrhea hospitalizations- between 55,000 and 70,000- prevented annually in the United States since the introduction of rotavirus vaccine.

In addition, the risk does not approach that associated with the older and no-longer-available RotaShield, licensed in 1998 and voluntarily withdrawn in 1999. The risk associated with that vaccine was 1 to 2 cases of intussusception per 10,000 vaccine recipients.

The researchers point out that their findings are consistent with those of postlicensure studies conducted in Australia, Mexico, and Brazil. They conclude that the benefits of rotavirus vaccination far outweigh the small increased risk of intussusception.