NCT01505647.

Methods	Study design: phase 3, randomised, double‐blind Duration: 182 days postvaccination
Participants	Inclusion criteria Setting: outpatient Country: not provided Number: 498 participants; treatment (N = 331), control (N = 166) Participants' health status: healthy participants with history of varicella or residence in a VZV‐endemic area for ≥ 30 years. Females of reproductive potential must have a negative pregnancy test and must agree to use acceptable methods of birth control. Age: mean 62.8 years Sex: 59.2% female Other relevant information: aged ≥ 50 years Exclusion criteria History of hypersensitivity reaction to any vaccine component, prior receipt of any varicella or zoster vaccine, prior history of herpes zoster, have recently had another vaccination, pregnant or breastfeeding, use of immunosuppressive therapy, known or suspected immune dysfunction, concomitant antiviral therapy
Interventions	Treatment group Live attenuated zoster vaccine AMP ˜ 0.65 mL SC (AMP); N = 331 Control group Live attenuated zoster vaccine ˜ 0.65 mL SC; N = 166
Outcomes	Number of participants with 1 or more adverse experiences Number of participants with 1 or more serious adverse experiences day 1 to 42 postvaccination Number of participants with 1 or more serious adverse experiences day 1 to 182 postvaccination
Purpose of the study	Safety and immunogenicity of LZV made with an Alternative Manufacturing Process (AMP) compared to LZV.
Funding sources	Merck Sharp & Dohme Corp
Conflicts of interest	Not described
Notes	Live attenuated zoster vaccine AMP ‐ live attenuated zoster vaccine manufactured with an alternative process Data were taken from clinicaltrials.gov/ct2/show/results/NCT01505647. ITT analyses
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