Levin 2000.

Methods	Study design: RCT, non‐blinded Duration: 36 months postvaccination
Participants	Inclusion criteria Setting: outpatient Country: USA Number: 167 participants; treatment (N = 82), control (N = 85) Participants' health status: healthy participants with a history of varicella but not herpes zoster Age: mean ˜ 66 years Sex: ˜ 55% female Other relevant information: aged 55 to 89 years Exclusion criteria Immunosuppressive illness or medication
Interventions	Treatment group Inactivated zoster vaccine (live vaccine heated at 56 °C for 7 days) SC; N = 82 Control group Live zoster vaccine SC (not specified if frozen); N = 85
Outcomes	Confirmed herpes zoster
Purpose of the study	"To compare a live attenuated varicella vaccine versus heat‐inactivated varicella vaccine in relation the confirmed cases of HZ and immunogenicity in individuals aged 55‐89 years"
Funding sources	Merck Research Laboratories, West Point, PA, USA
Conflicts of interest	Not described
Notes	Author answered our email and provided data for 1 clinical outcome. Most outcomes evaluated were immunologic. There is a misspelling of an author name on the paper: Dr Levin is referenced as Dr Levine.
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	High risk	Open study
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open study
Blinding of outcome assessment (detection bias) All outcomes	High risk	Open study
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not described
Selective reporting (reporting bias)	Unclear risk	Not described
Other bias	Unclear risk	Insufficient information