Rules Based on Patient's Age

• If a patient is >= 19 years of age and did NOT receive a shot of Hep A, then the Recommendation is Conditional and the reason code is HIGH_RISK.

• Shots administered to a patient who is >= 19 years of age will continue to be evaluated and, if valid, will count toward completion of the series.

Proof of Immunity Rules

• If a patient has immunity (reported as having a positive titer or serology) vaccine is not recommended; Recommendation is Not Recommended and the reason code is PROOF_OF_IMMUNITY.

• Any shot administered prior to the date of immunity is evaluated as Valid or Invalid, based on minimum age and minimum interval rules.

• Any shot administered on or after the date of immunity is evaluated as Accepted with a reason code of PROOF_OF_IMMUNITY unless the series is COMPLETE.

Rules for Recommending at the CVX Code vs. Vaccine Group Level

• When recommending in the Hep A 2-dose  Series, recommend at the vaccine group level.

• When recommending in the Hep A 3-Dose Series:

  • Recommend at the CVX level; the vaccine recommended should be CVX 104 (Hep A-Hep B (Twinrix)), along with supplemental text: "If the Twinrix vaccine (CVX 104) is not available, another age-appropriate Hep A vaccine may be administered." if the next recommended dose of Hep B is in the Hep B 3-Dose Twinrix Series at the same target dose number as Hep A, and the recommendation dates of the next Hep A dose and next Hep B dose are the same

  • Recommend at the vaccine group level if the above condition is not met.

• When recommending in the Hep A 4-dose Accelerated Twinrix Series, recommend at the CVX level; vaccine recommended for doses should be CVX 104 (Hep A-Hep B (Twinrix)).

  • If the next target dose is dose 4, return supplemental text: "If the Twinrix vaccine (CVX 104) is not available, another age-appropriate Hep A vaccine may be administered."

CVX Code Specific Rules

CVX Code Absolute Maximum Age

• If one of the CVX codes in the table above is administered above the absolute maximum age for that CVX code, then the Evaluation is Invalid and the reason code is ABOVE_MAXIMUM_AGE_VACCINE, per the ICE General Rule "Evaluation of Shots Above the Vaccine Code Absolute Maximum Age."

  • There is no interval required between the Invalid shot and the next target dose. 

Series Name

• Hep A 2-dose Series

• Hep A 3-dose Series

• Hep A 4-dose Accelerated Twinrix Series

Series Selection Rules

To accommodate the potential selection of the Twinrix series in the Hep A and Hep B vaccine groups, the series selection in Hep B is performed before the Hep A series selection.

In the Series Selection Rules rules below, if the Hep A 2-dose series was previously switched to the Hep A 3-dose Series, then replace "Hep A 2-dose Series" with "Hep A 3-dose Series".

If no doses have been administered, then the the Hep A 2-dose Series applies.

If the first dose was administered at < 18 years - 4 days, then the Hep A 2-dose Series applies.

If the first dose was administered at >= 18 years - 4 days, then the Hep A 2-dose Series applies unless one of the below conditions is not true:

• The Hep A 3-dose Series applies if one of the following conditions is true:

  • CVX 104 was administered as dose 1, there are no additional doses administered¹

• OR

  • CVX 104 was administered as dose 1 and/or dose 2, there are two or more doses administered, and dose 2 was administered >= 24 days and < 6 months - 4 days from dose 1¹

• The Hep A 4-dose Accelerated Twinrix Series applies if the following condition is true:

  • The Hep B series selection logic selected the Hep B 4-dose Accelerated Twinrix Series.

    • Exception: If there are 3 valid doses in the Hep A 3-dose Series, but < 4 valid doses in the Hep A 4-dose Accelerated Twinrix Series, series = Hep A 3-dose Series.

    • and there is a dose administered in the Hep A 3-dose Series where the administration date is after the latest dose in the Hep A 4-dose Accelerated Twinrix Series, and the Hep A 3-dose Series has fewer doses remaining to complete the series than the Hep A 4-dose Accelerated Twinrix Series, then select Hep A 3-dose Series.

    • If a previously administered (Valid) dose in the Hep A 4-dose Accelerated Twinrix Series that is Invalid in the Hep A 3-dose Series, change the evaluation to Accepted / VACCINE_NOT_COUNTED_BASED_ON_MOST_RECENT_VACCINE_GIVEN.

• If the Hep A 3-dose series or Hep A 4-dose series is selected, but the Hep A 2-dose series was completed before the Hep A 3-dose series or Hep A 4-dose series, change the selection to the Hep A 2-dose complete series.

  • If a previously administered (Valid) dose in the Hep A 3-dose series or Hep A 4-dose series is Invalid in the Hep A 2-dose series, change the evaluation to Accepted / VACCINE_NOT_COUNTED_BASED_ON_MOST_RECENT_VACCINE_GIVEN.

Notes

• ¹The Hep A series does not need to have the Hep B series be the 3-dose Twinrix series.  (The Hep B 3-dose Twinrix Series requires that this Hep A series (i.e. – the Hep A 3-dose Series) is selected, but this series (i.e – the Hep A 3-dose Series) does not require that the Hep B 3-dose Twinrix Series is selected.)

• If there are 3 valid doses in the Hep A 3-dose Series and 4 valid doses in the Hep A 4-dose Accelerated Twinrix Series, and both series are completed on the same day, series = Hep A 4-dose Accelerated Twinrix Series.

  • Example:

    • Dose 1: CVX 104 18y

    • Dose 2: CVX 104 18y7d

    • Dose 3: CVX 104 18y31d

    • Dose 4: CVX 104 19y

• For the Accelerated 4-dose Twinrix Series: The Hep B Series Selection Rules already performed necessary checks to confirm that Dose 1 and dose 2 are CVX 104 in both the Hep A and Hep B vaccine groups, that there are two or more doses administered, and dose 2 was administered >= 7 days and < 24 days from dose 1. As a result, we can simply check in this stage of the Hep A Series Selection logic if the Hep B 4-dose Accelerated Twinrix Series was selected; if it was, then the Hep A 4-dose Accelerated Twinrix Series should be selected as well.

Series Special Rules 

• Target dose 2 will be evaluated as valid if administered >= 6 months - 4 days from dose 1, even if there have been invalid shots administered. 

  • Example: If dose 1 is administered at 1 year, invalid shot 2 is administered at 1 year 5 months, and target dose 2 is administered at 1 year 6 months, then target dose 2 is evaluated as valid and counts as dose 2, completing the 2-dose series.

• If one of the following is true:

  • when evaluating target dose 1: CVX 104 is administered for target dose 1 at >= 18 years of age

  • when evaluating target dose 2: CVX 104 was previously administered for dose 1 at >= 18 years - 4 days, and CVX 104 was administered for target dose 2 at >= 24 days and < 6 months - 4 days from the last administered shot

  • when evaluating target dose 2: CVX 104 is administered for target dose 2 at >= 19 years of age, >= 24 days from the last administered shot

• and

  • if there is an administered dose 1, there must not exist an administered shot (of any type of Hep A vaccine) that is >= 6 months - 4 days from dose 1 and < 19 years of age

• then

  • Switch this series to the Hep A 3-dose Series, starting with the target dose that is being evaluated