Can I switch from Rotarix (rotavirus vaccine) to Rotasil (rotavirus vaccine) for an infant who has already received the first dose of Rotarix?

Switching from Rotarix to Rotasil After First Dose

Yes, you can switch from Rotarix to Rotasil (RotaTeq) after the first dose of Rotarix, and you should complete the series with a total of 3 doses when switching to or using RotaTeq. 1

Primary Recommendation

The AAP and ACIP explicitly state that rotavirus vaccination should not be deferred because the product used for a previous dose is not available, and the series should be continued or completed with the product available. 1

• When any dose in the series was RotaTeq (Rotasil) or the vaccine product is unknown for any dose, a total of 3 doses of rotavirus vaccine should be administered 1
• All doses must be completed by 8 months and 0 days of age 1
• The minimum interval between doses is 4 weeks 1

Practical Implementation for Your Case

Since the infant received one dose of Rotarix (RV1):

• Administer 2 additional doses of Rotasil (RotaTeq/RV5) to complete a 3-dose series 1
• Maintain at least 4 weeks between each dose 1
• Ensure all doses are completed before 8 months and 0 days of age 1

Evidence Supporting Interchangeability

While the AAP recommends completing the series with the same product whenever possible, no theoretical reason exists to expect increased adverse events when mixing products compared to using a single product throughout the series. 1

• No studies directly address interchangeability of the two rotavirus vaccine products, but safety concerns are not anticipated 1
• A mixed series is likely more effective than an incomplete series with one product 1
• Recent evidence from India demonstrated that Rotavac and Rotasiil can be safely used interchangeably, with non-inferior seroresponse rates (33.5% mixed regimen vs 29.6% single regimen) and no vaccine-related serious adverse events 2

Critical Age Restrictions to Monitor

Ensure the infant has not exceeded the maximum age for completing the series:

• The infant must complete all doses by 8 months and 0 days of age 1, 3
• If the first dose was given late, calculate whether there is sufficient time to complete 2 additional doses with 4-week intervals before the 8-month deadline 1, 3

Common Pitfall to Avoid

Do not assume only 2 total doses are needed because the infant started with Rotarix (which is normally a 2-dose series). When switching to or incorporating RotaTeq, or when the vaccine product is unknown, always give 3 total doses. 1