Anti-gE antibody concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and expressed as geometric mean concentrations (GMCs) in milli-international units per milliliter (mIU/mL).

Analysis was performed on the Per Protocol Set for analysis of persistence (LTFU phase), which included evaluable participants from the Enrolled Set with a complete vaccination course (2 doses of HZ/su vaccine) in the ZOSTER-041 study, who met the eligibility criteria and signed informed consent in the current study and for whom persistence immunogenicity results after primary vaccination course were available at the specified time points in the current study, regardless of revaccination status.

Anti-gE antibody concentrations were determined by ELISA and expressed as GMCs in mIU/mL.

Analysis was performed on the Per Protocol Set for Immunogenicity after revaccination course (Revaccination active phase), which included evaluable participants who were administered 1 or 2 doses of revaccination as per the revaccination schedule and who had immunogenicity data available for the specified analysis at the specified time points in the current study.

Frequency of gE-specific CD4 (2+) T-cells expressing two or more activation markers (from among interferon gamma [IFN-γ], interleukin-2 [IL-2], tumour necrosis factor alpha [TNF-α] and CD40 Ligand [CD40L]) was determined by intracellular cytokine staining (ICS) as measured by cytokine flow cytometry (CFC) and expressed in CD4(2+) T-cells per million cells [CD4(2+) T-cells/million cells].

Analysis was performed on a sub-cohort of participants from the Per Protocol Set for analysis of persistence (LTFU phase), for whom an additional blood sample for cell-mediated immunity (CMI) analysis was collected and who had CMI results available for the specified analysis at the specified time points in the current study.

SAEs assessed included any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization or resulted in disability/incapacity or was a congenital anomaly/birth defect in the offspring of a study participant. SAEs related to primary vaccination in ZOSTER-041 study were assessed by the investigator.

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 study who met the eligibility criteria and signed informed consent in the current study.

A suspected HZ case was defined as a new unilateral rash accompanied by pain (broadly defined to include allodynia, pruritus or other sensations) without alternative diagnosis.

A confirmed HZ case was diagnosed by an algorithm that included Polymerase Chain Reaction (PCR) and the HZ Ascertainment Committee (HZAC) determination.

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 study who met the eligibility criteria and signed informed consent in the current study.

A confirmed HZ case was diagnosed by an algorithm that included Polymerase Chain Reaction (PCR) and the HZ Ascertainment Committee (HZAC) determination.

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 primary study who met the eligibility criteria and signed informed consent in the current study.

The number of participants with biopsy for clinical indication (suspected) or surveillance protocol that was not biopsy-proven rejection and with biopsy-proven allograft rejections are reported. Biopsy-proven allograft rejections are defined as adverse events of specific interest (AESIs).

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 study who met the eligibility criteria and signed informed consent in the current study.

Biopsy-proven allograft rejection is defined as an adverse event of specific interest (AESI).

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 study who met the eligibility criteria and signed informed consent in the current study.

Declining allograft function (allograft dysfunction) was assessed through all clinically obtained serum creatinine values from 2 months prior to an episode of biopsy-proven rejection and up to 2 months after rejection resolution and cessation of therapeutic immunosuppressive therapy. Allograft dysfunction is defined as having a fold increase in serum creatinine of 1.2 greater from the reference timepoint (2 months prior to an episode of biopsy-proven rejection).

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 primary study who met the eligibility criteria and signed informed consent in the current study.

Declining allograft function was assessed through all clinically obtained serum creatinine values from 2 months prior to an episode of HZ and up to 2 months after HZ rash resolution. Allograft dysfunction is defined as having a fold increase in serum creatinine of 1.2 greater from the reference timepoint (2 months prior to an episode of HZ).

Analysis was performed on the Enrolled Set, which included all participants with a complete vaccination course (2 doses of HZ/su vaccine) in ZOSTER-041 study who met the eligibility criteria and signed informed consent in the current study.

Frequency of gE-specific CD4 (2+) T-cells expressing two or more activation markers (from among IFN-γ, IL-2, TNF-α and CD40L) was determined by ICS as measured by CFC and expressed in CD4(2+) T-cells/million cells.

Analysis was performed on a sub-cohort of participants from the Per Protocol Set for Immunogenicity after revaccination course (Revaccination active phase), for whom an additional blood sample for CMI analysis was collected and who had CMI results available for the specified analysis at the specified time points in the current study.

Persistence of humoral immunity after the revaccination course was evaluated in terms of anti-gE antibody concentrations. Anti-gE antibody concentrations were determined by ELISA and expressed as GMCs in mIU/mL.

Analysis was performed on the Per Protocol Set for persistence after revaccination course (Revaccination follow-up phase), which included evaluable participants who received 2 doses of revaccination in the current ZOSTER-073 study and for whom immunogenicity persistence results after revaccination were available for the specified analysis at the specified time points in the current study.

Frequency of gE-specific CD4 (2+) T-cells expressing two or more activation markers (from among IFN-γ, IL-2, TNF-α and CD40L) was determined by ICS as measured by CFC and expressed in CD4(2+) T-cells/million cells.

Analysis was performed on a sub-cohort of participants from the Per Protocol Set for persistence after revaccination course (Revaccination follow-up phase), for whom an additional blood sample for CMI analysis was collected and who had CMI results available for the specified analysis at the specified time points in the current study.

Assessed solicited administration site events included erythema, pain and swelling at injection site. Any = occurrence of the event regardless of intensity grade. Any erythema/swelling at injection site = erythema/swelling at injection site with a diameter larger than (>) 20 millimeters (mm). Grade 3 pain = significant pain at rest, which prevented normal, everyday activities. Grade 3 erythema/swelling at injection site = erythema/swelling at injection site with a diameter >100 mm.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and with the solicited administration site events diary card data available after the corresponding revaccination, for the specified duration.

Duration is the number of days in which a participant experienced the solicited administration site event within the 7-day solicited follow-up period. Assessed solicited administration site events included erythema, pain and swelling at injection site.

Analysis was performed on the Exposed Set for revaccination phase, which included participants with at least one HZ/su revaccination dose administered in the current study, with solicited diary data available after the corresponding revaccination, who experienced the specified solicited administration site event within 7 days following the respective revaccination dose and with the duration documented.

Assessed solicited systemic events included fatigue, gastrointestinal symptoms (including nausea, vomiting, diarrhea and/or abdominal pain), headache, myalgia, shivering and fever [temperature higher than or equal (>=) to 38.0 degrees Celsius (°C)/100.4 degrees Fahrenheit (°F)]. Any AE = occurrence of the event regardless of intensity grade. Grade 3 fatigue, gastrointestinal symptoms, headache, myalgia, shivering = event that prevented normal, everyday activities. Grade 3 fever = temperature higher (>) than 39°C/102.2°F. Related fatigue, gastrointestinal symptoms, headache, myalgia, shivering, fever = event assessed by the investigator as related to the revaccination. The preferred route for measuring temperature in this study was oral.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and with the solicited systemic events diary card data available after the corresponding revaccination, for the specified duration.

Duration is the number of days in which a participant experienced the solicited systemic event within the 7-day solicited follow-up period. Assessed solicited systemic events included fatigue, gastrointestinal symptoms (including nausea, vomiting, diarrhea and/or abdominal pain), headache, myalgia, shivering and fever.

Analysis was performed on the Exposed Set for revaccination phase, which included participants with at least one HZ/su revaccination dose administered in the current study, with solicited diary data available after the corresponding revaccination, who experienced the specified solicited systemic event within 7 days following the respective revaccination dose and with the duration documented.

An unsolicited AE was defined as any AE reported in addition to those solicited during the clinical study. Also, any 'solicited' symptom with onset outside the specified period of follow-up for solicited symptoms was reported as an unsolicited AE. Any = occurrence of the event regardless of intensity grade or relation to revaccination. Grade 3 = event that prevented normal, everyday activities. Related = event assessed by the investigator as related to revaccination.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom unsolicited AEs data were available for the specified duration.

SAEs assessed included any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization or resulted in disability/incapacity or was a congenital anomaly/birth defect in the offspring of a study participant. Any = occurrence of the SAE regardless of intensity grade or relation to revaccination. Fatal = SAE resulting in the death of the participant.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom SAEs data were available for the specified duration.

SAEs assessed included any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization or resulted in disability/incapacity or was a congenital anomaly/birth defect in the offspring of a study participant. Related = SAE assessed by the investigator as related to revaccination. Related-fatal = SAE resulting in the death of the participant assessed by the investigator as related to revaccination.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom SAEs data were available for the specified duration.

Biopsy-proven allograft rejection is defined as an adverse event of special interest (AESI) and is recorded in serious adverse event (SAE) screens, irrespective of the seriousness of the event. Related biopsy proven allograft rejections = biopsy-proven allograft rejections assessed by the investigator as related to revaccination.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom biopsy-proven allograft rejections data were available for the specified duration.

pIMDs are defined as a subset of AEs that include autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. Any = occurrence of the pIMD regardless of intensity grade or relation to revaccination. Related = pIMDs assessed by the investigator as related to revaccination.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom pIMDs data were available for the specified duration.

A confirmed HZ case was diagnosed by an algorithm that included Polymerase Chain Reaction (PCR) and the HZ Ascertainment Committee (HZAC) determination.

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom HZ cases data were available for the specified duration.

Declining allograft function was assessed through all clinically obtained serum creatinine values from 3 months before the first revaccination dose until 3 months after the last revaccination dose. Allograft dysfunction is defined as having a fold increase in serum creatinine of 1.2 greater from the reference timepoint (3 months prior to revaccination).

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom allograft dysfunction following revaccination data were available for the specified duration.

Declining allograft function was assessed through all clinically obtained serum creatinine values from 2 months prior to an episode of biopsy-proven rejection and up to 2 months after rejection resolution and cessation of therapeutic immunosuppressive therapy. Allograft dysfunction is defined as having a fold increase in serum creatinine of 1.2 greater from the reference timepoint (2 months prior to an episode of biopsy-proven rejection).

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom allograft dysfunction related to allograft rejection data were available for the specified duration.

Declining allograft function was assessed through all clinically obtained serum creatinine values from 2 months prior to an episode of HZ and up to 2 months after HZ resolution. Allograft dysfunction is defined as having a fold increase in serum creatinine of 1.2 greater from the reference timepoint (2 months prior to an episode of HZ).

Analysis was performed on the Exposed Set for revaccination phase, which included all participants with at least one HZ/su revaccination dose administered in the current study and for whom allograft dysfunction related to HZ episodes data were available for the specified duration.