CDC Study Shows Rotavirus Vaccine Caused a Decline in Infection Cases

Rotavirus is a contagious viral infection causing gastroenteritis that generally affects infants and young children. Symptoms include severe watery diarrhea, vomiting, fever, and abdominal pain. These symptoms can cause severe dehydration that can lead to hospitalization.

Pharmacists can play an important role in educating parents on the importance of the rotavirus vaccine.

The CDC studied the long-term impact of rotavirus vaccination on disease prevalence in the United States.¹ Laboratory testing data for rotavirus was analyzed through the CDC’s National Respiratory and Enteric Viruses Surveillance System (NREVSS) during the prevaccine (2000-2006) and postvaccine (2007-2018) periods. The median annual percentage of positive rotavirus tests declined significantly from 25.6% in the prevaccine period to 6.1% in the postvaccine period (p < 0.001). The study also found that vaccination reduced peak rotavirus activity and shortened the duration of the rotavirus season.¹

The study revealed data demonstrating the importance of rotavirus vaccination, as the NREVSS revealed important trends in the pre and postvaccine years. Limitations include that this was an observational study since information was analyzed through the database NREVSS. Additionally, data in NREVSS is reported without demographic or clinical information (including vaccination status). Observational studies can show associations but not cause-and-effect.

Rotavirus was the leading cause of severe diarrhea among infants and young children in the United States before the vaccine was introduced in 2006.² The vaccine prevents approximately 40,000 to 50,000 hospitalizations annually in the United States. RotaTeq and Rotarix are 2 rotavirus vaccines approved in the United States that are shown to be safe and effective, and they are administered by putting drops in the infant’s mouth. The vaccine is approximately 85% to 98% effective at protecting against severe rotavirus infection and hospitalization, and 74% to 87% effective against rotavirus illness of any severity.²

RotaTeq is given in 3 doses at 2 months, 4 months, and 6 months of age.² Rotarix is administered in 2 doses at 2 months and 4 months of age. Additionally, the first dose of either vaccine should be given before 15 weeks of age (minimum age 6 weeks), and all doses of the immunization should be administered before age 8 months.

Educate parents that there is no catch-up vaccination like other immunizations, and the rotavirus vaccine series should not be started after 15 weeks of age. Most adverse effects associated with the vaccine are mild and include irritability, diarrhea, and vomiting. Serious adverse effects are rare, but there is a small risk of intussusception, which is a type of bowel blockage.

References

• Hallowell BD, Parashar UD, Curns A, DeGroote NP, Tate JE. Trends in the Laboratory Detection of Rotavirus Before and After Implementation of Routine Rotavirus Vaccination-United States, 2000-2018. MMWR Morb Mortal Wkly Rep 2019;68:539-543. DOI: http://dx.doi.org/10.15585/mmwr.mm6824a2.
• Rotavirus. CDC website. https://www.cdc.gov/rotavirus/index.html. Last reviewed April 23, 2018. Accessed June 21, 2019.