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

HZ/su Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-HZ/su Dose 2, and with immunogenicity data available for the specified analysis at the specified time point post-HZ/su Dose 2.

Anti-S antibody concentrations were determined by Multiplex Electrochemiluminescence assay and expressed as GMCs in arbitrary units per milliliter (AU/mL).

mRNA-1273 Per Protocol Set (for HZ/su groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-mRNA-1273 dose, and with immunogenicity data available for the specified analysis at the specified time point post-mRNA-1273 dose.

Antibody titers against the 4 influenza strains (A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage) included in the FLU D-QIV vaccine were determined by hemagglutination inhibition and expressed as GMTs.

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time point post-Flu D-QIV dose.

Anti-S antibody concentrations were determined by Multiplex Electrochemiluminescence assay and expressed as GMCs in AU/mL.

mRNA-1273 Per Protocol Set (for Flu D-QIV groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time point post-mRNA-1273 dose.

A participant seroconverted for anti-HI antibodies against the 4 influenza strains is defined as a participant having either a pre-vaccination HI titer below (<) 1:10 and a post-vaccination HI titer greater than or equal to (≥) 1:40, or a pre-vaccination HI titer ≥ 1:10 and at least a 4 fold greater post-vaccination HI titer. The 4 influenza strains assessed were A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage.

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time point post-Flu D-QIV dose.

A participant seropositive for anti-gE antibodies is defined as a participant whose anti-gE antibody concentration was greater than or equal to the assay cut-off value (97 mIU/mL).

HZ/su Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-HZ/su Dose 2, and with immunogenicity data available for the specified analysis at the specified time points pre-vaccination and post-HZ/su Dose 2.

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

HZ/su Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-HZ/su Dose 2, and with immunogenicity data available for the specified analysis at the specified time points pre-vaccination and post-HZ/su Dose 2.

A participant with vaccine response for anti-gE is defined as a participant with:

• At least a 4-fold greater post-dose anti-gE antibodies concentration as compared to the pre-vaccination anti-gE antibodies concentration, for participants who were seropositive at pre-vaccination, or,
• At least a 4-fold greater post-dose anti-gE antibodies concentration as compared to the anti-gE antibodies cut-off value for seropositivity, for participants who were seronegative at pre-vaccination.

HZ/su Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-HZ/su Dose 2, and with immunogenicity data available for the specified analysis at the specified time point post-HZ/su Dose 2.

MGI is defined as the geometric mean of the within participant ratios of the post-vaccination anti-gE antibody concentration to the pre-vaccination anti-gE antibody concentration.

HZ/su Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-HZ/su Dose 2, and with immunogenicity data available for the specified analysis at the specified time points pre-vaccination and post-HZ/su Dose 2.

Anti-S antibody concentrations were determined by Multiplex Electrochemiluminescence assay and expressed as GMCs in AU/mL.

mRNA-1273 Per Protocol Set (for HZ/su groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-mRNA-1273 dose, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-mRNA-1273 dose.

Anti-S antibody concentrations were determined by Multiplex Electrochemiluminescence assay and expressed as GMCs in AU/mL.

mRNA-1273 Per Protocol Set(for Flu D-QIV groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-mRNA-1273 dose.

MGI is defined as the geometric mean of the within participant ratios of the post-vaccination anti-S protein antibody concentration to the pre-vaccination anti-S protein antibody concentration.

mRNA-1273 Per Protocol Set (for HZ/su groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination up to blood sample collection post-mRNA-1273 dose, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-mRNA-1273 dose.

MGI is defined as the geometric mean of the within participant ratios of the post-vaccination anti-S protein antibody concentration to the pre-vaccination anti-S protein antibody concentration.

mRNA-1273 Per Protocol Set(for Flu D-QIV groups) included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-mRNA-1273 dose.

Antibody titers against the 4 influenza strains (A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage) included in the FLU D-QIV vaccine were determined by hemagglutination inhibition and expressed as GMTs.

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-Flu D-QIV dose.

A participant seroprotected for anti-HI antibodies against the 4 influenza strains included in the FluD-QIV vaccine is defined as a participant with a serum HI titer ≥ 1:40. The 4 influenza strains assessed were A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage. The age categories assessed were 18-64 and ≥ 65 years of age (YOA).

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-Flu D-QIV dose.

A participant seropositive for anti-HI antibodies against the 4 influenza strains included in the FluD-QIV vaccine is defined as a participant with a serum HI titer ≥ 1:10. The 4 influenza strains assessed were A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage.

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-Flu D-QIV dose.

MGI is defined as the geometric mean of the within participant ratios of the post-vaccination reciprocal HI titer to the pre-vaccination reciprocal HI titer. The 4 influenza strains assessed were A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage.

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-Flu D-QIV dose.

A participant seroconverted for anti-HI antibodies against the 4 influenza strains is defined as a participant having either a pre-vaccination HI titer < 1:10 and a post-vaccination HI titer ≥ 1:40, or a pre-vaccination HI titer ≥ 1:10 and at least a 4 fold greater post-vaccination HI titer.

The 4 influenza strains assessed were A/H1N1 strain, A/H3N2 strain, B/Victoria lineage and B/Yamagata lineage. The age categories assessed were 18-64 and ≥65 years of age (YOA).

Flu D-QIV Per Protocol Set included all participants who met all eligibility criteria, received all doses as per assignment, for whom administration site of study vaccine was known, who did not receive any other prohibited concomitant intervention, did not meet any of the criteria for elimination during the study through the last blood sample for the group, and with immunogenicity data available for the specified analysis at the specified time points pre- and post-Flu D-QIV dose.

The assessed solicited local AEs included axillary (underarm) swelling or tenderness, pain, pruritus, redness and swelling. Axillary swelling or tenderness was solicited for all participants and not restricted to mRNA-1273 recipients as was originally planned per protocol. Pruritus was solicited for all participants and not restricted to HZ/su recipients as was originally planned per protocol.

The HZ/su and mRNA-1273 Exposed set (for solicited safety analysis) included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented and with the electronic diary completed post-each vaccination.

The assessed solicited local AEs included axillary (underarm) swelling or tenderness, pain, pruritus, redness and swelling. Axillary swelling or tenderness was solicited for all participants and not restricted to mRNA-1273 recipients as was originally planned per protocol. Pruritus was solicited for all participants and not restricted to HZ/su recipients as was originally planned per protocol.

The Flu D-QIV and mRNA-1273 Exposed set (for solicited safety analysis) included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented and with the electronic diary completed post-each vaccination.

The assessed solicited systemic AEs included abdominal pain, arthralgia, chills, diarrhea, fatigue, fever, gastrointestinal symptoms, headache, myalgia, nausea and vomiting. Fever is defined as temperature ≥ 38.0 degrees Celsius (°C)/100.4 degrees Fahrenheit (°F) by any route. The preferred location for measuring temperature was the oral route.

The HZ/su and mRNA-1273 Exposed set (for solicited safety analysis) included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented and with the electronic diary completed post-each vaccination. Here, 'number analyzed' = participants with available data for each specified category.

The assessed solicited systemic AEs included abdominal pain, arthralgia, chills, diarrhea, fatigue, fever, gastrointestinal symptoms, headache, myalgia, nausea and vomiting. Fever is defined as temperature ≥ 38.0°C/100.4°F by any route. The preferred location for measuring temperature was the oral route.

The Flu D-QIV and mRNA-1273 Exposed set (for solicited safety analysis) included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented and with the electronic diary completed post-each vaccination. Here, 'number analyzed' = participants with available data for each specified category.

An unsolicited AE was defined as any AE that was either not included in the list of solicited events using a participant diary, or was included in the list of solicited events, but with an onset more than 7 days following administration of a study intervention.

The HZ/su and mRNA-1273 Exposed set (for unsolicited safety analysis) included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented and with unsolicited AEs data available for the specified duration post-vaccination. Here, 'number analyzed' = participants with available data for each specified category.

An unsolicited AE was defined as any AE that was either not included in the list of solicited events using a participant diary, or was included in the list of solicited events, but with an onset more than 7 days following administration of a study intervention.

The Flu D-QIV and mRNA-1273 Exposed set (for unsolicited safety analysis) included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented and with unsolicited AEs data available for the specified duration post-vaccination. Here, 'number analyzed' = participants with available data for each specified category.

An unsolicited AE was defined as any AE that was either not included in the list of solicited events using a participant diary, or was included in the list of solicited events, but with an onset more than 7 days following administration of a study intervention.

The HZ/su and mRNA-1273 Exposed set (for unsolicited safety analysis) included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented and with unsolicited AEs data available for the specified duration post-vaccination. Here, 'number analyzed' = participants with data available for each specified category.

An unsolicited AE was defined as any AE that was either not included in the list of solicited events using a participant diary, or was included in the list of solicited events, but with an onset more than 7 days following administration of a study intervention.

The Flu D-QIV and mRNA-1273 Exposed set (for unsolicited safety analysis) included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented and with unsolicited AEs data available for the specified duration post-vaccination. Here, 'number analyzed' = participants with data available for each specified category.

An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant, was considered or defined as an important medical event, or abnormal pregnancy outcomes.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant, was considered or defined as an important medical event, or abnormal pregnancy outcomes.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant, was considered or defined as an important medical event, or abnormal pregnancy outcomes.

The Flu D-QIV and mRNA-1273 Exposed set included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented.

An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant, was considered or defined as an important medical event, or abnormal pregnancy outcomes.

The Flu D-QIV and mRNA-1273 Exposed set included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented.

The assessed pIMDs included autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have had an autoimmune etiology.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

The assessed pIMDs included autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have had an autoimmune etiology.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

AESIs were defined as medical concepts that may have been related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

AESIs were defined as medical concepts that may have been related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

AESIs were defined as medical concepts that may have been related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance.

The Flu D-QIV and mRNA-1273 Exposed set included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented.

AESIs were defined as medical concepts that may have been related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance.

The Flu D-QIV and mRNA-1273 Exposed set included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented.

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

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

Primary Case Definition: Experienced at least TWO of following systemic symptoms: fever (temperature ≥38ºC), chills, myalgia, headache, sore throat, new olfactory & taste disorder(s), OR at least ONE of following respiratory signs: cough, shortness of breath or difficulty breathing, OR clinical or radiographical evidence of pneumonia; AND must have at least one nasopharyngeal (NP) or nasal swab, or saliva or respiratory sample positive for SARS-CoV-2 by PCR.

Secondary Case Definition: Following systemic symptoms: fever, or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle aches or body aches, headache, new loss of taste or smell, sore throat, nasal congestion or rhinorrhea, nausea or vomiting, or diarrhea AND a positive NP or nasal swab, or saliva or respiratory sample for SARS-CoV-2 by PCR.

Tertiary Case Definition: Documented COVID-19 diagnosis made by health care provider and not meeting the above case definitions.

The HZ/su and mRNA-1273 Exposed set included all participants in the HZ/su and mRNA-1273 booster cohort (HZ/suSeq and HZ/suCoAd groups) with at least 1 vaccine administration documented.

Primary Case Definition: Experienced at least TWO of following systemic symptoms: fever (temperature ≥38ºC), chills, myalgia, headache, sore throat, new olfactory & taste disorder(s), OR at least ONE of following respiratory signs: cough, shortness of breath or difficulty breathing, OR clinical or radiographical evidence of pneumonia; AND must have at least one nasopharyngeal (NP) or nasal swab, or saliva or respiratory sample positive for SARS-CoV-2 by PCR.

Secondary Case Definition: Following systemic symptoms: fever, or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle aches or body aches, headache, new loss of taste or smell, sore throat, nasal congestion or rhinorrhea, nausea or vomiting, or diarrhea AND a positive NP or nasal swab, or saliva or respiratory sample for SARS-CoV-2 by PCR.

Tertiary Case Definition: Documented COVID-19 diagnosis made by health care provider and not meeting the above case definitions.

The Flu D-QIV and mRNA-1273 Exposed set included all participants in the Flu D-QIV and mRNA-1273 booster cohort (FluD-QIVSeq and FluD-QIVCoAd groups) with at least 1 vaccine administration documented.