Either at the time of administration or at some point afterwards, factors affecting the potency of a dose administered may be known. For example, at the time of administration, the provider may know that less that the full intended amount of vaccine was administered (eg the patient moved unexpectedly and only part of the dose was actually adminstered). Or after the dose has been reported, the manufacturer may inform the provider that the lot of vaccine was sub-potent due to a manufacturing issue. In these cases, it's important to flag the dose as potentially being sub-potent.

Note that this sort of declaration is different than an "evaluation" of the dose (using the ImmunizationEvaluation resource) where the dose is compared to published recommendations. In this case, the dose is assumed to be fully potent (unless noted otherwise) but may still not be "valid" because of issues such as the age of the age of the patient at the time of administration or the interval since a previous dose.

Proposed resolution would be to add a two new elements:

isPotent - a boolean indicating whether or not the dose is fully potent (Y) or sub-potent (N). If not populated, the dose should be assumed to be fully potent

subpotentReason - would be a codeable concept with an extensible value set of reasons why the dose is subpotent. Suggested values would be:

-Partial dose

-Cold chain break

-Manufacturing problem

-Manufacturer recall