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Vaccine Information


Entry last updated: May 28, 2004

- Understanding the Disease
- Available Vaccines
- History of the Vaccine
- Who Should and Should Not Receive the Vaccine
- Dose Schedule
- Effectiveness of the Vaccine
- Known Side Effects
- Related Issues
- Key References and Sources of Additional Information

Understanding the Disease

Rotavirus is an intestinal virus that infects virtually all children by three years of age. It is the most common cause of diarrhea in children, including hospital-acquired diarrhea, and childcare center outbreaks are common. The disease usually lasts a week or longer and can cause persistent infection in immunocompromised people. Most rotavirus infections are mild, but about 1 in 50 cases develop severe dehydration. Each year in the U.S., rotavirus results in the hospitalization of 50,000 infants younger than two years of age. In developing countries, rotavirus leads to an estimated 480,000 to 640,000 deaths each year.

Available Vaccines


History of the Vaccine

RotaShield�, a reassortant rhesus-human rotavirus vaccine tetravalent (RRV-TV), was licensed by the Food and Drug Administration (FDA) in August 1998. However, in July 1999, after approximately 1 million children had been immunized with the vaccine, the CDC recommended that use of the rotavirus vaccine be temporarily suspended. The CDC was concerned that the vaccine might be causing a serious bowel disease called "intussusception," since 15 cases of this condition had been reported in children who had received the vaccine. The vaccine was voluntarily withdrawn from the market by the manufacturer in October 1999.

Subsequent studies reported that an infant's risk of developing intussusception indeed increased after receiving RotaShield�, especially within one or two weeks after immunization. In one study, the records of 463,277 infants, 56,253 of whom had received one or more doses of RRV-TV, were reviewed. Investigators calculated that the risk of intussusception attributable to the vaccine was 1 per 11,073 infants vaccinated, three times higher than for the unvaccinated children in this study. The risk of intussusception was greatest three to seven days after the first dose (Kramarz et al. 2001). Another study of infant medical records examined 429 infants with intussusception and 1,763 healthy children matched by age. While only 12.8% of the healthy children had been vaccinated, 17.2% of children with intussusception had received RotaShield�. This study estimated that if a national rotavirus vaccine program were re-implemented, 1 case of intussusception out of 4,670 to 9,474 cases could be attributed to the vaccine (Murphy et al. 2001). However, in another study that reviewed the medial records of children hospitalized for intussusception in New York, researchers found that only a few more cases of intussusception were documented during the year the vaccine was administered, than in the years before RotaShield� was introduced (Chang et al. 2001).

Those who received the rotavirus vaccine in 1998 and 1999 are not at continuing risk of developing intussusception.

Who Should and Should Not Receive this Vaccine

No rotavirus vaccine is recommended for use at this time, though vaccine trials are in progress.

Dose Schedule


Effectiveness of the Vaccine


Known Side Effects

Before the vaccine was voluntarily withdrawn from the market, the relative risk of RRV-TV associated intussusception was calculated to be almost three times higher than in unvaccinated infants. No deaths have been attributed to side effects of the vaccine, although some infants required surgical intervention to alleviate the intussusception.

Related Issues

There are several mechanisms in place to assure that licensed vaccines are safe. Prelicensure clinical studies are the first step, but are limited by a relatively small number of individuals in the study groups. After licensure, vaccines are monitored for safety by the Vaccine Adverse Events Reporting System (VAERS) and the Vaccine Safety Datalink. The reports to VAERS served to alert the CDC to the probability that there is an increased risk for intussusception among infants receiving the rotavirus vaccine.

Although a recent study reported that RRV-TV caused few additional cases of intussusception (see History of the Vaccine), it still seems that the vaccine has some connection to intussusception, especially since the intussusception cases observed during the year RotaShield� was on the market more often occurred in the early weeks following vaccination, instead of throughout the year. Further studies need to be done in states with large populations of children who received the rotavirus vaccine. If the vaccine is found to have�only a weak link to intussusception, scientists may conclude that the vaccine's benefits outweigh its risks, especially in developing countries where many children die from rotavirus diarrhea.

Trials examining several other rotavirus vaccines are in progress.

Key References and Sources of Additional Information


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Including available vaccines, history of the vaccine, who should and should not receive it, dose schedules, effectiveness, known side effects, and related issues.

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