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 (called intussusception), affecting about 1 in 10,000 to 1 in 30,000 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 (intussusception) affecting about 1 in 100,000 children, usually occurring within a week after getting the first or second dose of vaccine. Of interest, natural rotavirus is also a rare cause of intussusception. Because both current rotavirus vaccines prevent rotavirus — and therefore prevent this rare 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 to 30,000 doses administered. Because RotaShield caused this side effect, it was removed from the recommended vaccine schedule and is no longer available in the U.S.

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 calf strains of rotavirus. In 2008, Rotarix was licensed. It 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, the rotavirus vaccine has been added back to the U.S. infant immunization schedule and is recommended for all infants.

Does rotavirus vaccine decrease the incidence of type 1 diabetes?

Natural rotavirus infection has been found to be a possible cause of type 1 diabetes in children. Because of this potential, several research groups were interested to see what would happen following widespread use of rotavirus vaccine. They wondered whether the frequency of type 1 diabetes diagnoses in children would increase, decrease, or remain unchanged once the vaccine was in use.

The Australian researchers compared the frequency of type 1 diabetes diagnoses in the eight years before and the eight years after rotavirus vaccine was introduced (2007 in that country). They found that between 2000 and 2015, 16,159 cases of newly diagnosed type 1 diabetes were reported. In children 0 to 4 years of age, the number of incident cases of type 1 diabetes decreased by 14%. This protective effect wasn’t observed in children 5 to 9 or 10 to 14 years of age; both of these groups were born before the rotavirus vaccine became available.

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.

Disease risks

• Fever
• Vomiting and diarrhea
• Dehydration caused by severe vomiting and diarrhea can be fatal
• Very rarely, intestinal blockage called intussusception (estimated to be about 1 in 100,000 infections)

Vaccine risks

• Low-grade fever
• Mild vomiting and diarrhea
• Very rarely, intestinal blockage called intussusception (1 in 100,000 doses)

Reference

Plotkin SA, Orenstein W, Offit PA, and Edwards KM. Rotavirus vaccines in Vaccines, 7th Edition, 2018, 950-969.

Reviewed by Paul A. Offit, MD, on January 02, 2024