Rotavirus Vaccination: 5 Things to Know

A droopy, listless 4-month-old is rushed to the emergency department by his very worried parents, who report that he started having "explosive" diarrhea less than 24 hours ago. He was "his usual self" before that and has been generally healthy since birth.

Before vaccines were available in the United States, rotavirus disease was very common, with almost every child infected by age 5. The virus can spread quickly in a daycare center or household, primarily by the fecal-oral route, often when toddlers put their fingers or a contaminated object in their mouths. The virus is stable in the environment and can live on contaminated surfaces or objects for up to 10 days, and occasionally lives in water or food.

Fortunately, scenes like the one described above are less common in the post-vaccine era. What should you know about rotavirus vaccination?

1. Rotavirus vaccine should be given to infants at 2, 4, and sometimes 6 months.

The Centers for Disease Control and Prevention (CDC) recommends routine vaccination of infants with either of the two available vaccines:

RotaTeq (RV5), licensed in 2006, given in three doses at ages 2 months, 4 months, and 6 months
Rotarix (RV1), licensed in 2008, given in two doses at ages 2 months and 4 months

The first dose of either vaccine should be given before 15 weeks of age, and all doses should be given before the age of 8 months, regardless of gestational age. Both vaccines are given orally.

2. Rotavirus vaccines are safe and effective at preventing rotavirus disease.

Both rotavirus vaccines are more than 85% effective at preventing severe rotavirus gastroenteritis. During the first year of a child's life, rotavirus vaccine provides:

85%-98% protection against severe rotavirus disease and resulting hospitalization
74%-87% protection against rotavirus disease of any severity

Rotavirus vaccines are safe, but there is a small risk for intussusception; rotavirus vaccines cause an estimated one additional case of intussusception for every 20,000-100,000 US infants. Given the significant declines in rotavirus disease, the benefits of rotavirus vaccination are considered to outweigh the small increased risk for intussusception.

Neither the vaccine nor natural infection will provide full immunity from future rotavirus infections, so children may develop rotavirus disease more than once. Children who are not vaccinated tend to have the most severe symptoms the first time they get rotavirus disease. Children who are vaccinated are less likely to get rotavirus and are more likely to have milder symptoms if infected.

3. The rotavirus vaccination program has reduced the prevalence and altered the seasonal patterns of rotavirus disease in the United States.

In a new study comparing pre- and post-rotavirus vaccine periods, CDC observed that the proportion of positive test results for rotavirus was dramatically reduced from an annual median of 26% in the pre-vaccine era to 6% in the post-vaccine era. Peak rotavirus activity also declined by more than two thirds, from an annual median of 43% in the pre-vaccine era to 14% in the post-vaccine era, while the duration of the rotavirus season was shortened from a median of 26 weeks to a median of 9 weeks.

Before rotavirus vaccine was introduced in 2006, cases of rotavirus disease in the United States peaked annually in the winter and spring months. Since then, a biennial rotavirus seasonal pattern has been established, with alternating years of low and high disease activity.

The biennial trend observed in the United States could be attributed to low vaccination coverage, with the number of susceptible children accumulating in low rotavirus activity years, which leads to a larger number of children without immunity the following season—and thus an increase in infections.

4. Rotavirus vaccination rates are lower than those for other childhood vaccines.

Rotavirus vaccination rates among US children aged 19-35 months remain lower than those for other childhood vaccines among children in the same age group. The 2017 national vaccination coverage for rotavirus vaccine was 73%, compared with greater than 90% coverage for poliovirus, MMR, HepB, and varicella vaccines.

5. Low rotavirus vaccination coverage rates among children contribute to rotavirus outbreaks.

Because rotavirus vaccination coverage lags behind that of other childhood vaccines, many children remain susceptible to severe rotavirus disease. Rotavirus vaccination is most effective against severe disease, so even vaccinated individuals may develop mild cases. Vaccination reduces transmission and might confer indirect protection to unvaccinated individuals. Rotavirus outbreaks will continue to occur, however, even among highly vaccinated populations and among adults.

Healthcare providers should continue to consider rotavirus infection in children who present with acute gastroenteritis, while making strong recommendations to parents for rotavirus vaccination and administering the vaccines to eligible infants according to CDC recommendations.