Drug Criteria & Outcomes: Test Your Vaccine Knowledge: Rotarix® and RotaTeq®
Drug Criteria & Outcomes
Test Your Vaccine Knowledge: Rotarix® and RotaTeq®
Part II of a Series on Vaccines
By Meagan Widener, PharmD Candidate, Harrison School of Pharmacy, Auburn University
The vaccines available today afford benefit to a wide range of ages: infants, adolescents, adults, and the elderly. Many of the vaccines provide a proactive response to the conditions that were treated only retrospectively just a few years ago.1
This article is a continuation of the July 2008 evaluation of Gardasil® and will focus on Rotarix® and RotaTeq®. The goal of the information presented is to inform and update health care professionals about these vaccines and to improve screening for potential candidates at each encounter. Cases are presented below with background information about the disease, then the vaccine and appropriate follow-up are discussed.
Rotavirus Vaccines
Case: TT is a 6-week-old male, who presents today with diarrhea and signs of slight dehydration. No fever or other complaints are noted. During the visit, the patient's mother inquires about the new two-dose rotavirus vaccine, Rotarix, her friend's baby just received. She wants her baby to receive the vaccine today, but she is worried that since she is breastfeeding the vaccine will not be as effective. Is this patient a candidate for the Rotarix vaccine?
Background: Rotavirus gastroenteritis is the most common cause of diarrhea in infants and children and contributes to the hospitalization of 55,000 children in the United States each year. Worldwide, it contributes to more than 600,000 deaths of children annually. Four rotavirus strains have been identified in 96% of the cases worldwide: G1, G2, G3, and G4. Recently, the G9 serotype is beginning to emerge as a main contributor to cases of rotavirus as well.
Prevalence of strains varies with both time of year and location. In the United States, rotavirus is most prevalent November through April. Infants and children are most affected by rotavirus, typically becoming infected by age 2. When adults are infected, severity is minimal and symptoms are mild. In children, the virus typically has a two-day incubation period, which precedes 3-8 days of symptoms.3
Diarrhea, malabsorption, and fluid loss occur due to the rotavirus infection at the edges of the small intestinal villi. Non-bloody diarrhea can present in up to 10-20 episodes per day.4 Other symptoms experienced include vomiting, fever, and abdominal pain. Viral shedding occurs before the symptom onset and lasts on average about 2 weeks in children (adults shed the virus in a shorter period and in lower amounts). Transmission usually occurs through the fecal-oral route, but some documented transmissions have occurred through body fluids. Patients develop partial immunity after the infection, and repeat infections present less severely than the initial infection.3
Vaccine mechanism: Rotarix and RotaTeq are live, attenuated vaccines that begin viral replication in the small intestine to induce immunity to the rotavirus. Rotarix is indicated to protect against gastroenteritis caused by G1, G3, G4, and G9 serotypes, and is expected to be available before the end of 2008.5 RotaTeq protects against gastroenteritis caused by G1, G2, G3, G4 serotypes.6 Because these agents are live vaccines, the potential for spread of the infection to other non-infected individuals is possible. Shedding of the administered vaccine occurs in the fecal matter of the child, peaking 7 days after administration of the first dose. Transmission via this route was not evaluated in the studies of each of these vaccines.5
Candidates for the vaccine: The Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) recommend that all infants who fall within the suggested age ranges for the vaccines should be immunized against rotavirus.6 Children ages 6 weeks to 20 weeks are candidates to begin the Rotarix series, while those ages 6-12 weeks old are candidates to begin the RotaTeq series. Studies indicate that no restrictions are needed on the intake of food, liquid, or breast milk before or after vaccination with either agent. Rotarix and RotaTeq has been studied and found to be safe in combination with other routine childhood vaccines.5,7
Those who should not receive the vaccine: Because both vaccines contain live virus, administration is contraindicated in infants who are immunocompromised or currently suffer from acute febrile illnesses. Infants that are vomiting or experiencing diarrhea should not be given the vaccine until these conditions subside.5
If the patient has a history of hypersensitivity to a dose or any component of the vaccine, further doses should be discontinued. Those with latex allergy should receive the Rotarix vaccine with extreme caution because the oral delivery devices contain latex. RotaTeq liquid solution administration tubes are latex free, and might be preferred if the patient has a latex allergy.7 Congenital malformations are a contraindication to the vaccine because this predisposes the patient to risk of intussusception. Safety and efficacy have not been established in infants with other chronic gastrointestinal conditions.5
Administration: Prior to immunization, the guardian should receive the Vaccine Information Statements, a requirement by the National Childhood Vaccine Injury Act of 1986. Rotarix is given as a two-dose series with each dose of 1 mL oral suspension administered to the inside of the infant's cheek while the infant is in the reclining position. If the infant spits out or emits most of the administered dose, a single replacement dose can be given during the same visit. Both doses should be given between 6 and 24 weeks of age, with the second dose following the first by at least 4 weeks.
Before reconstitution, the lyophilized powder vial must be refrigerated. During reconstitution, supplied diluents must be used and the preparation should be discarded if particulate matter or abnormal colors are noted in the product. If the vaccine is not administered soon after reconstitution, it can either be stored in a refrigerator (not freezer) or kept at room temperature protected from light for up to 24 hours, at which time it should then be discarded.5
RotaTeq is given in a three-dose series with each dose of 2 mL oral liquid administered in a similar manner as Rotarix. If the infant receives a partial dose of RotaTeq due to vomiting or regurgitation, a replacement dose should not be administered, as this has not been studied.
RotaTeq does not require reconstitution because it is pre-prepared in liquid form in plastic dosing tubes. The series should begin between 6 and 12 weeks of age. Initiation of the series is not indicated for infants older than 12 weeks. Subsequent doses should follow at 4-10 week intervals, with all doses being administered by 32 weeks old.
RotaTeq should be stored in the refrigerator and used quickly after removal.7 It is recommended to complete the vaccine series with the same brand of vaccine. If however, the product used previously is not available or unknown, the dose should be administered with either available brand. If any of the doses in the series may have been RotaTeq, three doses must be given to complete the full series.6
Efficacy: The ACIP considers both vaccines to be equally efficacious and successful at preventing rotavirus infections and related hospitalizations; however, safety and efficacy are unknown with either agent after the patient has been exposed to the virus. Study outcomes indicate that about 85%-98% protection is derived against severe rotavirus diseases and 72%-87% protection is gained against any rotavirus disease.6
The efficacy of Rotarix in pre-term infants is not established; however, RotaTeq has been studied in this population and has proven efficacy when dosed according to the infant's age in weeks since birth.5,7 RotaTeq also has proven efficacy in infants with controlled gastroesophageal reflux disease.7
Adverse reactions: Common side effects of Rotarix include vomiting, loss of appetite, diarrhea, cough, runny nose, and fever. None of the adverse effects reported greatly deviated from placebo findings. Adverse effects with RotaTeq are similar and include diarrhea, vomiting, irritability, otitis media, nasopharyngitis, and bronchospasm.7
Unlike the previously discontinued rotavirus vaccine, Rotatsheild®, the newest agents only have limited, post-marketing evidence of intussusception occurrence. One other rare condition that has developed after administration of both vaccines in a limited set of patients is Kawasaki disease. Other post-marketing reports from outside the United States include thrombocytopenia purpura, maladministration, and hematochezia.5
Patient cost: The current cost of the RotaTeq three-dose series is about $210.8 The price of Rotarix has yet to be disclosed, but it is estimated that the two-dose series will cost approximately $200.9 To ensure that rotavirus vaccine is administered to all eligible infants possible, the CDC has included the RotaTeq vaccine in the Vaccines for Children program.
Further research: Additional studies need to be performed to determine the efficacy of the vaccine if the entire series is not administered and to evaluate efficacy of both vaccines in those with chronic gastrointestinal diseases. The risk of transmission due to viral shedding and contact with bodily fluids besides fecal matter also needs to be evaluated since it was not addressed in the study of either vaccine.10
Patient follow-up: This patient should not receive the vaccine at this visit. The fact that the infant's mother is breastfeeding is not a reason to deny the vaccine. The reason to withhold is that patients with active diarrhea or fever are discouraged from obtaining the live vaccine until the symptoms subside. The infant should return when well to be given the first dose of Rotarix, which should precede the second dose by at least 4 weeks. The patient's mother should also be informed that the series should be completed by the time her son reaches 24 weeks old.
References
- Red Book® Online Table – Status of Licensure and Recommendations for New Vaccines. Red Book Online by American Academy of Pediatrics. Available at: http://aapredbook.aappublications.org/news/vaccstatus.shtml. Accessed June 6, 2008.
- Euler GL, Lu P, Singleton JA. Vaccination coverage among U.S. adults National Immunization Survey – Adult 2007. Available at: www.cdc.gov/vaccines. Accessed June 6, 2008.
- Centers for Disease Control and Prevention. Rotavirus: About Rotavirus. Atlanta, GA. Available at: www.cdc.gov/rotavirus. Accessed June 16, 2008.
- Zimmerman RK, Middleton DB, Kimmel SR. Vaccines across the life span. J Fam Pract 2007;56:S1-S33.
- Rotarix® [package insert]. Research Triangle Park, NC. GlaxoSmithKline; April 2008.
- Cortese M, Chilton L. Proposed Recommendations from the ACIP Rotavirus Vaccines Working Group. Atlanta, GA: Centers for Disease Control and Prevention. Available at: www.cdc.gov/vaccines. Accessed June 16, 2008.
- RotaTeq® [package insert]. Whitehouse Station, NJ. Merck & Co., Inc.; April 2008.
- CDC Vaccine Price List: Pediatric/VFC Vaccine Price List. Atlanta, GA: Centers for Disease Control and Prevention. Available at: www.cdc.gov/vaccines/. Accessed June 6, 2008.
- Shah M. GlaxoSmithKline: progress for Rotarix in key U.S. market. Pharmaceutical Business Review. Available at: www.pharmaceutical-business-review.com. Accessed June 16, 2008.
- Parashar U, Alexander J, Glass R. Prevention of Rotavirus Gastroenteritis Among Infants and Children. Recommendations of the Advisory Committee on Immunization Practices (AICP). MMWR. Atlanta, GA: Centers for Disease Control and Prevention. Available at: www.cdc.gov/mmwr. Accessed June 6, 2008.
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