Two vaccines for the prevention of herpes zoster (shingles) are licensed for use in the United States and recommended by the Advisory Committee on Immunization Practices (ACIP). RZV and ZVL are two completely different vaccines. They differ by type, dose, schedule, ACIP recommendation, route of administration, and storage requirements. CDC noted that administration errors are reported most frequently after vaccine licensure and publication of recommendations.
Zoster vaccine live (ZVL; Zostavax, Merck), licensed in 2006,* is a live attenuated virus vaccine administered as a single subcutaneous (SQ) dose. Although the Food and Drug Administration (FDA) approved ZVL for adults aged ≥50 years, ACIP recommends ZVL for immunocompetent adults aged ≥60 years (1). Recombinant zoster vaccine (RZV; Shingrix, GlaxoSmithKline), licensed October 2017,† is also approved by the FDA for adults aged ≥50 years and is recommended by ACIP for immunocompetent adults aged ≥50 years (2). RZV is administered as a 2-dose intramuscular (IM) series, with the second dose given anytime from 2 to 6 months after the first. RZV is preferentially recommended by ACIP over ZVL (2). Furthermore, ACIP recommends that persons previously vaccinated with ZVL receive the full 2-dose RZV series (2) (CDC).
CDC monitored administration errors of these vaccines from October of 2017 to February of 2018 through the Vaccine Adverse Event Reporting System (VAERS). The VAERS is a national program managed by the CDC to monitor identification of adverse effects and administration errors. There were 155 documented reports of administration errors involving RZV. The table below from an article written by Jennifer Gershman, PharmD, CPh, and published in Pharmacy Times, highlights the reported administration errors.
Table: Vaccine Administration Errors1
| Vaccine Error | Vaccine Error Description |
|---|---|
|
Inappropriate route of administration |
Administered RZV by subcutaneous (SQ) route instead of IM route; caused injection site reactions (e.g. pain, erythema, and pruritus) |
|
Inappropriate age |
Vaccine administration to patients 39 and 48 years of age |
|
Wrong drug information distributed |
Two patients received the vaccine information statement for ZVL instead of RZV |
|
Lack of patient counseling |
Two patients did not receive instructions to return for the second dose |
|
Administration of wrong vaccine |
RZV was administered instead of the intended varicella (Varivax) vaccine with unreported age |
|
Incorrect storage |
Administration of RZV vaccine after frozen storage |
|
Failure to reconstitute |
Administration of the adjuvant component without reconstitution with the vaccine antigen |
These are only errors that have been reported and it is highly likely that other errors have occurred which were not documented via the VAERS. Most of the administration errors reported occurred in a pharmacy, but this could be related to pharmacy’s stronger commitment to reporting. It is important that all healthcare sites administering vaccines continue to report errors to the VAERS to support continued market education.
Although data from passive reporting to VAERS and inquiries submitted to CDC limit the ability to draw conclusions regarding the cause of the administration errors, early monitoring indicates the following:
- Vaccine providers might confuse administration procedures and storage requirements of the older ZVL and the newer RZV.
- Failure to reconstitute the vaccine and administration of only one component of RZV also appears to be occurring, like errors observed for other vaccines that require mixing.
- Whereas RZV administered through the appropriate IM route is associated with high rates of local and systemic reactions, erroneous SQ injection can increase the likelihood of these episodes.
- Some errors, like improper storage and preparation could potentially affect vaccine effectiveness.
Continued education and awareness around the correct storage, handling, preparation, and administration guidelines for RZV and ZVL will help vaccine providers, pharmacies included, reduce errors related to Recombinant Zoster Vaccine. For more information, visit “Notes from the Field” on the CDC website.
For more information on properly storing refrigerated vaccines, such as RZV, download our Ultimate Guide to Vaccine Storage.
