Gilderman 2008.

Methods	Study design: RCT, double‐blind Duration: 28 days postvaccination
Participants	Inclusion criteria Setting: outpatient Country: USA, multicentre Number: 367 participants; treatment (N = 182), control (N = 185) Participants' health status: healthy participants, immunocompetent individuals with a history of varicella or residence in a country where VZV infection is endemic Age: mean ˜ 63 years old Sex: ˜ 55% female Other relevant information: aged ≥ 50 years 68.1% white participants Exclusion criteria "Subjects were excluded if they had a clinical history of hypersensitivity or anaphylactic reactions to gelatin or neomycin, used any form of non topical antiviral therapy, had received a live vaccine within 4 weeks prior to the study dose or an inactivated vaccine within 1 week prior to the study dose, or another vaccination was planned before the subject was due to complete the study. Study exclusions also included a history of HZ, pregnancy, or breastfeeding; the plan to conceive within the duration of the study; known or suspected immune dysfunction; and alcohol or other substance abuse that might interfere with the evaluation required by the study."
Interventions	Treatment group Zoster vaccine refrigerated SC; N = 182 Control group Zoster vaccine frozen SC; N = 185
Outcomes	Participants with follow‐up Participants with 1 or more adverse events Participants with serious adverse events Vaccine‐related serious adverse events Death Participants who discontinued due to any AE Participants who discontinued due to a vaccine‐related AE
Purpose of the study	"To support the development of a refrigerator‐stable formulation of Zostavax with a confirmatory clinical trial with varicella‐zoster virus antibody‐seropositive adults ≥50 years of age"
Funding sources	Merck & Co Inc
Conflicts of interest	“Other than those authors who are employees of Merck & Co., Inc. (as indicated in the affiliations), L.I.G., J.F.L., and T.M.N. have been investigators for the sponsor. Employees may hold stock and/or stock options in the company.”
Notes	1 participant withdrew consent prior to intervention. No ITT analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind, with in‐house blinding
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The formulations were visually indistinct, supplied in identical glass vials.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Clear participant flow
Selective reporting (reporting bias)	Low risk	Adverse events prespecified by the investigators were reported in the results section for both refrigerated and frozen zoster vaccines.
Other bias	Unclear risk	Insufficient information