What Should I Know About the Rotavirus Vaccine?

One of the earliest vaccines that doctors recommend for infants is the one for rotavirus. Rotavirus is the most common cause of severe diarrhea in infants and children, and nearly all children will be infected by the age of five. The dehydration and electrolyte imbalance caused by rotavirus can be most problematic in the very young, however, and it is recommended that the rotavirus vaccine be given beginning at six to twelve weeks of age. Two more doses are then administered at approximately eight week intervals. The rotavirus vaccine should not be given before six weeks of age or after 32 weeks of age.

The Centers for Disease Control (CDC) state that rotavirus causes 20 to 60 deaths per year in the United States, and 500,000 deaths worldwide. The staggering difference in fatalities is largely due to unsanitary conditions, lack of available routine medical care and scant resources for treating dehydration in underdeveloped nations.

The duration of immunity provided by the rotavirus vaccine is unknown. It is believed to last for at least two rotavirus seasons – wherein the virus is most commonly contracted during cold weather – although experts note that the vaccine’s effectiveness is lower during the second season than during the first. After all three doses are given, the effectiveness of the rotavirus vaccine is estimated to be 74% against any rotavirus infection, and 98% against a severe infection.

The first rotavirus vaccine, Rotashield, was licensed in August, 1998 but was withdrawn the next year due to an association between the vaccine and intussusception, or obstruction of the bowel, in infants who had received the vaccine. RotaTeq was later licensed in 2006 and, although reports of intussusception do not exceed the CDC’s expected amount, this rotavirus vaccine is also labeled with a warning to be watchful for signs of bowel obstruction. No safety data for this vaccine is available for infants with weakened immune systems or with a history of gastrointestinal disorders.

More common side effects of the rotavirus vaccine include diarrhea and vomiting, affecting up to 24% of vaccinated infants. The virus was also found to be shed in the stools of up to 8.9% of vaccinated infants and children, and may continue to shed for up to fifteen days. Since rotavirus enters the body through the mouth and spread via fecal-oral contact, caregivers should be especially diligent about hand washing when caring for a child who has received the rotavirus vaccine to prevent the spread of rotavirus to others.

It can be argued that the rotavirus vaccine often produces the very effect that it is intended to protect infants against. In fact, infants younger than three months of age are rarely infected with rotavirus, due to passive maternal antibodies and, if applicable, antibodies received through breast milk. These infants will nonetheless be exposed to the live rotavirus during this time of natural immunity if given the vaccine according to schedule. Furthermore, the child will likely experience a rotavirus infection later on, once the vaccine’s effectiveness has waned. After the first infection of rotavirus, 88% of children become immune to severe symptoms, and immunity only strengthens with each (usually symptom free) subsequent infection.

Other concerns may arise from the statement from manufacturer Merck Vaccine Division that “RotaTeq has not been evaluated for its carcinogenic or mutagenic potential or its potential to impair fertility.” Merck also states that “a relationship between antibody responses to RotaTeq against rotavirus gastroenteritis has not been established.” In other words, they have not proven a relationship between their vaccine and immunity to the virus.

Rotavirus is treated with rest, fluids and a bland diet until the child stops vomiting. In severe cases, an IV may be needed to help prevent dehydration. Because this virus is rarely fatal in developed nations and is preventable through proper hand washing, parents and caregivers may pause to consider the risks versus the benefits of the rotavirus vaccine before giving their consent. As with any vaccine, the risk of adverse reactions may be diminished by opting to have it administered separately from any other vaccine.