Questions & Answers

When did a rotavirus vaccine become available?
A vaccine to prevent rotavirus gastroenteritis was first licensed in August 1998 but was withdrawn in 1999 because of its association with an uncommon type of bowel obstruction called “intussusception.”

In February 2006, the U.S. Food and Drug Administration (FDA) approved a new rotavirus vaccine, RotaTeq (by Merck). In April 2008, FDA approved a second rotavirus vaccine, Rotarix (by GlaxoSmithKline).

What kind of vaccine are they?
RotaTeq and Rotarix are both live attenuated (weakened) viral vaccines.

How is this vaccine given?
Both RotaTeq and Rotarix are given to babies orally (swallowed).

Who should get this vaccine?
National experts on immunization (such as the Centers for Disease Control and Prevention and the American Academy of Pediatrics) recommend routine vaccination of all infants with rotavirus vaccine.

What is the recommended schedule for getting this vaccine?
Both vaccines are given in a series: RotaTeq vaccine is given in a 3-dose series with doses given at ages 2, 4, and 6 months; Rotarix vaccine is given in a 2-dose series with doses given at ages 2 and 4 months.

The first dose of either vaccine can be given as early as age 6 weeks or as late as age 14 weeks, 6 days. Vaccination should not be started for infants once they reach their 15 week birthday. There must be at least 4 weeks between doses and all doses must be given by age 8 months. Rotavirus vaccine may be given at the same time as other childhood vaccines.

Should an infant who has already been infected with rotavirus still be vaccinated?
Yes. Infants who have recovered from a rotavirus infection may not be immune to all of the virus types present in the vaccine. Therefore, just like infants who have never had rotavirus disease, infants who have previously had rotavirus disease should still complete the vaccine series if they can do so by age 8 months.

How safe is this vaccine?
Clinical trials to determine the safety and effectiveness of the RotaTeq vaccine involved more than 70,000 infants in 11 countries. Because of the association of the earlier rotavirus vaccine with a type of intestinal blockage called intussusception, a study designed specifically to assess a risk of intussusception was conducted before licensure of RotaTeq. The vaccine was given to 35,000 children and another 35,000 were given a placebo (salt water). There was no difference in the incidence of intussusception between the two groups.

As with all vaccines, the safety of this vaccine is being monitored after licensure by the U.S. Food and Drug Administration (FDA) and by CDC through the Vaccine Adverse Event Reporting System. In addition, Merck and Co., Inc., has committed to monitoring the safety of the vaccine in a large number of U.S. infants. CDC will also conduct a large study in its Vaccine Safety Datalink Program, which evaluates vaccine safety among approximately 80,000 U.S. infants every year. Also, for the first three years of licensure, the manufacturer will report cases of intussusception to FDA within 15 days of receiving them, and all other serious side effects will be reported on a monthly basis.

As a result of this aggressive monitoring, on February 13, 2007, the FDA released a report on the number of intussusception cases reported since RotaTeq licensure. The number reported fell within what was expected and gives assurance that the vaccine does not pose an elevated risk for intussusception. To read the report, go to www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm142404.htm. To read a CDC Q&A about the report, go to www.cdc.gov/vaccinesafety/vaers/rotateq.htm.

In clinical trials, infants who received RotaTeq vaccine and those who didn’t were monitored to determine if there were other possible side effects associated with the vaccine. Compared with infants who did not receive the vaccine, infants who did receive the vaccine had a slightly higher rate of diarrhea and vomiting within the first week and within the first 42 days after receiving the vaccine.

The FDA’s approval of Rotarix in 2008 was based on clinical trials involving nearly 75,000 infants. These clinical trials were conducted in the Americas, Europe, Asia and Africa and reflect an ethnically diverse population.

In a controlled safety study conducted in Latin America and Finland, the risk of intussusception was evaluated in 63,225 infants. No increased risk of intussusception was detected among those infants who received the vaccine and those who did not.

As with all vaccines, the safety of this vaccine is being monitored after licensure by the U.S. Food and Drug Administration (FDA) and by CDC through the Vaccine Adverse Event Reporting System and other systems. In addition, GlaxoSmithKline has committed to monitoring the safety of the vaccine in a large number of U.S. infants. Also, for the first three years of licensure, the manufacturer will report any serious and unexpected adverse events to FDA within 15 days of receiving them, and all other initial adverse experience reports will be reported on a monthly basis.

In clinical trials, infants who received Rotarix vaccine and those who didn’t were monitored to determine if there were other possible side effects associated with the vaccine. Compared with infants who did not receive the vaccine, infants who did receive the vaccine had a slightly higher rate of cough or runny nose within the first week after receiving the vaccine and a slightly higher rate of irritability within the first month after receiving the vaccine.

How effective is rotavirus vaccine?
Rotavirus vaccine is very effective against rotavirus disease. Studies show the vaccine to be highly effective (85%-98%) against severe rotavirus disease and very effective against rotavirus disease of any severity (74%-87%) through approximately the first rotavirus season after vaccination. Chances that children will need to be hospitalized for rotavirus disease are also greatly decreased (96%) by the vaccine. Neither vaccine will prevent diarrhea or vomiting caused by other germs.

What side effects have been reported with rotavirus vaccine?
Vaccinated infants are slightly (1%-3%) more likely to be irritable or to have mild, temporary diarrhea or vomiting after getting a dose of vaccine than infants who did not get the vaccine. Moderate or severe reactions have not been associated with the vaccine.

Who should NOT receive rotavirus vaccine?
Any child who has had a severe (life-threatening) allergic reaction to a previous dose of rotavirus vaccine should not get another dose. A child with a severe (life-threatening) allergy to any component of rotavirus vaccine should not get the vaccine. Because the oral applicator for Rotarix contains latex rubber, infants with a severe (anaphylactic) allergy to latex should not be given Rotarix; the RotaTeq dosing tube is latex-free. Rotavirus vaccine is contraindicated in infants diagnosed with the rare genetic disorder severe combined immune deficiency (SCID). Although this vaccine has not been associated with intussusception, as a precaution it is suggested that the risks for and the benefits of vaccination should be considered when vaccinating infants with a previous episode of intussusception.

Children who are moderately or severely ill at the time the vaccination is scheduled should probably wait until they recover, including children who are experiencing diarrhea or vomiting. Healthcare providers will decide on a case-by-case basis whether to vaccinate a child with an ongoing digestive problem, an immune system weakened because of HIV/AIDS or another disease that affects the immune system, or a child who is receiving treatment with drugs such as long-term steroids or treatment for cancer.
 

Questions and answers about rotavirus disease

Technical content reviewed by the Centers for Disease Control and Prevention, March 2010