NCT00886613.

Methods	Study design: phase 3, randomised, double‐blind Duration: 28 days postvaccination
Participants	Inclusion criteria Setting: outpatient Country: not provided Number: 120 participants; treatment (N = 80), control (N = 40) Participants' health status: healthy participants with prior history of varicella Age: between 60 and 88 years (mean not available) Sex: 61.7% female Other relevant information: aged ≥ 60 years Exclusion criteria Individuals with hypersensitivity reaction to any vaccine component, prior history of herpes zoster, have received any varicella or zoster vaccine including Zostavax, have a history of immunosuppression caused by disease, corticosteroids, cancer therapy, or organ transplant, have an active cancer, have received or will receive a live virus vaccine or an inactivated virus vaccine 4 weeks prior to participating in study (with the exception of influenza vaccine), and bedridden or homebound
Interventions	Treatment group Heat LZV (V212): 2 SC injections of 0.65 mL administered 31 days apart; N = 41 LZV (V212‐003): 2 SC injections of 0.65 mL administered 31 days apart; N = 39 Control group Placebo 2 SC injections of 0.65 mL administered 31 days apart; N = 40
Outcomes	Adverse events 1 to 28 days post‐any vaccine dose
Purpose of the study	A study to evaluate immunity to varicella zoster virus after immunisation with V212 vaccine or Zostavax (V212‐003)
Funding sources	Merck Sharp & Dohme Corp
Conflicts of interest	Not described
Notes	HLZV (heat‐treated LZV) The data from this study where LZV and placebo were compared were evaluated in comparison 1 (LZV versus placebo). ITT analyses NCT00886613 Data were taken from clinicaltrials.gov/ct2/show/results/NCT00886613
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	Unclear risk	"Masking: Double (Participant, Investigator)", but the masking process is not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"Masking: Double (Participant, Investigator)", but the masking process is not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Masking: Double (Participant, Investigator)", but the masking process is not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Clear patient flow
Selective reporting (reporting bias)	Low risk	All data on effectiveness and adverse events proposed in the methodology were presented in the results for both groups.
Other bias	Unclear risk	Insufficient information