The Centers for Disease Control and Prevention approved a rotavirus vaccine for use in all infants in the United States in 2006. The vaccine, called RotaTeq®, is given as a series of three doses by mouth at 2 months, 4 months and 6 months of age and can be given with other vaccines typically administered at those times. A second vaccine, called Rotarix®, was approved for use in June 2008 and is given as a series of two doses by mouth at 2 months and 4 months of age.
- The disease
What is rotavirus?
Rotavirus is a virus that infects the lining of the intestines. Although not typically known by its name, most parents recognize rotavirus by its symptoms — high fever, persistent and severe vomiting and diarrhea. By 5 years of age nearly all children have been infected with rotavirus.
Before the vaccine, each year in the United States, rotavirus caused:
- Illness in 2.7 million children, usually between 6 months and 24 months of age
- 500,000 doctor visits
- 55,000 to 70,000 hospitalizations
- 20 to 60 deaths
- The vaccine
How is the rotavirus vaccine made?
The first rotavirus vaccine, RotaTeq, is made from a strain of rotavirus that was originally isolated from a calf. Human rotavirus proteins responsible for evoking protective antibodies, but incapable of causing disease, were also added. This combination of a calf rotavirus, which can't cause disease in children, with human rotavirus proteins, which protect against disease, allows babies to develop immunity without getting sick.
The second rotavirus vaccine, Rotarix, is made from one type of rotavirus originally isolated from a person and weakened in the lab.
Does the rotavirus vaccine have side effects?
Studies of more than 130,000 infants showed that the vaccine did not cause vomiting, diarrhea, fever, irritability or poor feeding.
In 1999, a different rotavirus vaccine, called Rotashield®, was removed from the market because it was found to cause a rare form of intestinal blockage, affecting about 1 in 10,000 children. The Rotashield vaccine was made using a strain of rotavirus originally isolated from a monkey and is no longer available in the U.S.
The current rotavirus vaccines have also been found to be rare causes of intestinal blockage affecting about 1 in 100,000 children. Of interest, natural rotavirus is also a rare cause of intestinal blockage. Because both current rotavirus vaccines prevent rotavirus — and therefore prevent a rare form of intestinal blockage — the question became which was rarer, intestinal blockage caused by the vaccine or by natural infection. The question can be answered by looking at what happened to the rate of intestinal blockage once vaccination started to replace natural infection. Most recent evidence shows that the incidence of intestinal blockage of infants in the United States has not increased because of rotavirus vaccines.
- Other questions you might have
Why was the rotavirus vaccine removed from the schedule in 1999 and then put back in 2006?
The first rotavirus vaccine, known as RotaShield, was approved for use in 1998; however, less than one year later it was removed from the market because of an increased risk of a rare form of intestinal blockage called intussusception. Intussusception is an uncommon, yet painful intestinal blockage that occurs when the intestine folds into itself. This side effect of the vaccine was found to occur in about 1 recipient for every 10,000 doses administered. Because RotaShield caused this side effect, it was removed from the recommended vaccine schedule.
In 2006 and 2008, two new rotavirus vaccines were licensed. Both vaccines were made of different versions of the virus as compared to RotaShield, which contained monkey strains of rotavirus. In 2006, RotaTeq was licensed containing cow strains of rotavirus. The latter vaccine to be licensed was Rotarix, which contains a weakened human strain of rotavirus. Both vaccines were tested extensively before licensure to determine if they too caused intussusception. The rate of intussusception in those who received the rotavirus vaccine was found to be similar to that which occurred naturally — about 1 of every 100,000 infants. Because virtually every young child gets rotavirus, and about 1 of every 65 are hospitalized as a result, the benefit of getting the rotavirus vaccine clearly outweighs the risk. Therefore, rotavirus has been added back to the infant immunization schedule and is recommended for all infants.
- Relative risks and benefits
Do the benefits of the rotavirus vaccine outweigh the risks?
Without a rotavirus vaccine, approximately 55,000 to 70,000 children born in the United States would be hospitalized with rotavirus each year. Since the vaccine has been in use, this number has decreased by about 80 percent. There are no severe side effects from rotavirus vaccine. Therefore, the benefits of the rotavirus vaccine clearly outweigh the risks.
- Vomiting and diarrhea
- Dehydration caused by severe vomiting and diarrhea can be fatal
- Low-grade fever
- Mild vomiting and diarrhea
Plotkin SA, Orenstein W, and Offit PA. Rotavirus vaccines in Vaccines, 6th Edition, 2012, 669-687.