CHAPTER 17
Rotavirus and other enteric vaccinations
Rotavirus vaccination
Introduction
Rotavirus is a double-stranded RNA virus that is serotyped by its glycoprotein (G) and protease-sensitive protein (P) types. The majority of rotaviral infections in the United States are due to the P[8]G1 strain (78%) and the P[4]G2 strain accounts for 9%, with the remaining 13% consisting of numerous other strains.
Infection with rotavirus causes gastroenteritis leading to severe dehydration. Symptoms in the initial 24 hours include high fever and vomiting, and usually culminate in severe diarrhea. Severe episodes of gastroenteritis are most prevalent in young children, with nearly 1 in every 50 children worldwide being hospitalized for rotavirus by 5 years of age. The principal season of rotaviral infections begins in the southwestern United States in December and reaches its peak in northeastern United States in late April to May.
Pharmacology
There are two currently available rotaviral vaccines. One is a monovalent vaccine (RV1 – Rotarix) that contains a single rotavirus strain (G1P1A[8]). The other, a pentavalent vaccine (RV5 – Rotateq) includes four rotaviruses composed of human outer capsid proteins (G1, G2, G3, G4) and the bovine P7[5] attachment protein and one additional rotavirus with the human P1A[8] attachment protein and a bovine outer capsid protein. Both RV1 and RV5 are approved for use in the United States.
Mechanism of action
RV1 and RV5 are orally-administered, inactivated-viral vaccines that result in active immunization against rotavirus.
Indications for vaccination
Children are particularly vulnerable to rotavirus infection and experience the greatest morbidity. Thus, the vaccine is suggested for all infants with the first dose given between 2 months to 14 weeks and 6 days.
Dosing and administration
RV5 (Rotateq)
Primary immunization: single 2 mL dose is supplied in single-dose squeezable tube/applicator. The standard schedule for RV5 is at ages 2, 4, and 6 months (with ≥4 weeks between doses). The series must be completed by 8 months of life as it has not been studied in older infants.
RV1 (Rotarix)
Primary immunization: single 1 mL dose is reconstituted from lyophilized vaccine and diluent. The standard schedule for RV1 is at ages 2 and 4 months (with ≥4 weeks between doses). The series must be completed by 8 months of life as it has not been studied in older infants.
Co-administration of vaccines: Rotaviral vaccine can be given concurrently with the other pediatric vaccines.
Preterm infants can be vaccinated as early as 6 weeks of age if healthy (such as at the time of hospital discharge). They should be vaccinated at the same chronological age as full-term infants.
Note: The rotaviral vaccine series should be completed using the same product, although unavailability of the desired product should not prevent completion of the series with the alternate product.
Adverse effects
A rhesus-based tetravalent vaccine (RRV-TV, Rotashield) was licensed for use in 1998 to prevent severe rotaviral gastroenteritis. Post-licensing analysis revealed a 20-fold increased risk of intussusception in the 2 weeks after immunization with the estimated risk to be close to 1 case of intussusception per 10 000 vaccinated infants. As a result, RRV-TV was taken off the market.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
