Shingrix is given as a two-shot series, separated by 2 to 6 months per CDC (Centers for Disease Control) recommendations as this elicits the optimal immune response against the varicella-zoster (i.e. shingles) virus.
The first and second doses of Shingrix are exactly the same. There is no difference between them. Therefore, it is impossible to get the first shot "twice" by mistake.
In fact, Shingrix is only manufactured as one product. In other words, there isn't any packaging or mark on the vials stating 'dose one' and 'dose two'.
The Shingrix vaccine (both doses) comes as two vials that must be reconstituted prior to injection.
- One vial contains a single-dose of the lyophilized varicella-zoster virus surface glycoprotein E (gE) antigen component (appears as a white powder).
- The other vial contains an adjuvant suspension (appears as opalescent, colorless to pale brownish liquid). As a side note, an adjuvant is a component that enhances the immune response). The adjuvant in Shingrix is AS01B.
To reconstitute Shingrix, the adjuvant suspension component is transferred via syringe into the lyophilized gE antigen component vial. The resulting reconstituted suspension contains the following components:
- Recombinant gE antigen
- MPL (3-O-desacyl-4’- monophosphoryl lipid A)
- QS-21 (saponin purified from plant extract Quillaja saponaria Molina)
- Sucrose (as a stabilizer)
- Sodium chloride
- DOPC (dioleoyl phosphatidylcholine)
- Potassium dihydrogen phosphate
- Sodium dihydrogen phosphate dihydrate
- Disodium phosphate anhydrous
- Dipotassium phosphate
- Polysorbate 80
Shingrix does not contain preservatives and the total volume injected intramuscularly is 0.5 mL.
Answer SummaryBoth Shingrix doses (with administration separated by 2 to 6 months) are exactly the same product. It is not possible to accidentally give or get them out of order.