rotavirus vaccine

From Medscape Medical News
American Academy of Pediatrics Updates Guidelines for Use of Rotavirus Vaccine
News Author: Laurie Barclay, MD
CME Author: Charles P. Vega, MD, FAAFP
04/30/2009

There are now 2 vaccines against rotavirus licensed in the United States: one derived from 5 human-bovine strains (RV5) and one from a single human strain (RV1). Although both vaccines are live, attenuated oral vaccines, the dosing schedule for the 2 vaccines differs.
RV5 should be administered in 3 doses at ages 2, 4, and 6 months, and RV1 is a 2-dose series delivered at ages 2 and 4 months.

The current policy statement from the AAP examines the efficacy and safety data for both vaccines.


Study Highlights

The AAP does not express a preference for the use of RV5 or RV1.
The vaccines have been evaluated in 11 randomized trials involving more than 146,000 infants worldwide.
Both vaccines are well tolerated. They do not appear to promote fever or severe fever more than placebo. RV5 is associated with a small increase in the incidence of vomiting and diarrhea vs placebo.
Intussusception has not been associated with either vaccine, whether in clinical trials or, in the case of RV5, postmarketing analysis.
Both vaccines result in viral shedding in the stool (9% of children receiving RV5 and 25% of children receiving RV1). However, this viral shedding has not been documented to promote any new infections with rotavirus.
Vaccine efficacy studies demonstrated protection rates of 74% to 87% against any rotavirus disease and 85% to 98% against severe rotavirus disease.
No studies have addressed the interchangeability of the 2 vaccines. Although children should ideally be continued to receive the rotavirus vaccine they began, clinicians should not delay dosing because a product is unavailable. The available vaccine should be used.
A cost-benefit analysis demonstrated that the estimated cost per case of rotavirus averted was $139.00 for RV5 and $94.00 for RV1. However, the researchers cautioned that this cost difference might not be reflected in clinical practice.
Because latex rubber is used in the RV1 applicator, children with severe latex allergy should not receive RV1.
Clinicians should use caution in administering the rotavirus vaccines to children with altered immunocompetence. However, preliminary data suggest that the vaccines may be safe in children with HIV infection in Africa.
Children with moderate to severe acute gastroenteritis or other moderate to severe acute illness may defer the vaccination until a later date. However, children with mild illness should receive the vaccine to avoid failing to complete the series.
No data are available regarding the administration of the vaccines to children with a history of intussusception.
Repeated dosing in children who immediately regurgitate or vomit their dose of rotavirus vaccine is not recommended.
Preterm infants should receive the rotavirus vaccine, and those who are age-eligible should receive the vaccine at the time of discharge from the hospital. This obviates the theoretic risk for transmission of rotavirus in the hospital because of asymptomatic viral shedding after the vaccine.
The maximal age at the first dose of either vaccine is 14 weeks and 6 days, and the maximal age for the last dose of the vaccine is 8 months. The minimal interval between rotavirus vaccines is 4 weeks.

Clinical Implications

RV5 and RV1 are both live, attenuated vaccines, but they are derived from different sources and have different schedules of administration.
The AAP does not recommend one rotavirus vaccine vs the other. Both vaccines are efficacious and do not promote fever more than placebo. Both vaccines may be administered during cases of mild gastroenteritis, but the vaccine should not be readministered when a child regurgitates the dose.