Q. What is dosing schedule?
A. Monovalent live vaccine (RV1) (Rotarix by GSK) is given orally in two doses minimum 4 weeks apart. It is provided as a lyophilized powder that is reconstituted just before administration. Each reconstituted 1 ml dose of vaccine contains at least 106 median culture infective dose (CCID50) of live attenuated virus G1P1[8] and no preservative. It can be given after 6 weeks and not after 12 weeks and completed prior to 32 weeks. Recently FDA has extended the deadline of first dose up to 14 weeks and 6 days. Pentavalent live vaccine (RV5) (Rotateq by MSD) is given orally in 3 doses at age 2 , 4 and 6 months. First dose should be given between age 6-12 weeks and subsequent at 4-8 weeks interval. First dose can be extended up to 14 week and 6 days (recent FDA approval). All doses should be completed before 32 weeks.

In case a dose is missed, it is not necessary to restart the course but it should be completed within the time frame. In preterm stable newborn if he has completed 6 weeks, is clinically stable and discharged from NICU, rotavirus vaccine can be given.

Q. Since rotavirus infections are severe in the first 2 years of life, why can't these vaccines be given in children beyond 32 weeks of life?
A. Initial rotavirus vaccine was associated with intussusception and was withdrawn from market because of it. Incidence of intussusception is maximum around 9 months of age. Though newer vaccines are not associated with increased incidence of intussusception but their safety beyond 8 months is not proven due to lack of data hence it is not approved beyond 8 months. Initially rotavirus vaccine was licensed only up to 6 months of age, but with increasing usage and safety deadline was extended by FDA.

Q. How are the rotavirus vaccines stored and administered?
A. Rotavirus vaccines are stored at 2-8 o C and is protected from light . Monovalent rotavirus vaccine can be stored at room temperature. Do not freeze the diluents or vaccine. Monovalent vaccine (RV1) can be administered within 24 hours of reconstitution, but pentavalent vaccine (RV5) should be used immediately after reconstitution.

Q. What are side effect and contraindication of rotavirus vaccine?
A. Both rotavirus vaccines are safe and well tolerated with occasional vomiting, diarrhea. Intussusception incidence is not increased but caution is recommended in children with uncorrected congenital malformation of GI tract which predispose to intussusception. The vaccine is contraindicated in infant who has history of severe allergy (e.g. anaphylaxis) to rotavirus vaccine previously. Human monovalent vaccine oral applicator contains latex hence this is contraindicated in infant with severe latex allergy.

The vaccines should not be given in children with history of previous intussusceptions or immunodeficiency.

Q. What should be done if a child spits the vaccine?
A. Readministration of vaccine is not require if infant spits, vomits or regurgitates during or after administration of vaccine though manufacturers of human monovalent vaccine recommend the dose may be repeated at the same visit. The infant should receive the remaining recommended doses as per routine schedule.

Q. Can the 2 rotavirus vaccines be interchanged to complete the schedule?
A. Ideally schedule should be completed with the same product. If previous product is unknown or was bovine pentavalent vaccine than total of three doses should be administered.

Q. How effective are rotavirus vaccines?
A. Both vaccines are highly immunogenic in developed nations with overall effectiveness of 75 -87% against any rotavirus diarrhea and 90-95% against severe RVGE. Monovalent rotavirus vaccine in developing countries (South Africa and Malawi) has demonstrated efficacy of 61.2% (44-73.2%) overall in developing countries. (11) Pentavalent vaccine has demonstrated efficacy against severe RVGE at 2 years of 48.3% (22.3-66.1%) in Bangladesh and Vietnam. (5, 12)