A Study of Ad26.COV2.S in Adults (COVID-19)

Cohorts 1a and 1b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after vaccination 1 in Cohorts 1a and 1b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days post-vaccination 1 on Day 1 (Day 8)

Cohorts 1a and 1b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after vaccination 2 in Cohorts 1a and 1b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after vaccination 2 on Day 57 (Day 64)

Cohorts 1a and 1b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited local AEs for 7 days after ad hoc booster vaccination in Cohorts 1a and 1b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after ad hoc booster vaccination (Day 488 up to Day 604)

Cohorts 2a and 2b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after vaccination 1 in Cohorts 2a and 2b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after Vaccination 1 on Day 1 (Day 8)

Cohort 2a: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Booster Vaccination 1

Number of participants with solicited local AEs for 7 days after booster vaccination 1 in Cohort 2a were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after booster vaccination 1 on Day 183 (Day 190)

Cohort 2a: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Booster Vaccination 2

Number of participants with solicited local AEs for 7 days after booster vaccination 2 in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after booster vaccination 2 on Day 366 (Day 373)

Cohort 2a: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited local AEs for 7 days after ad hoc booster vaccination in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after ad hoc booster vaccination (Day 384 up to Day 451)

Cohort 2b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after Vaccination 2 in Cohort 2b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after Vaccination 2 on Day 57 (Day 64)

Cohort 2b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Booster Vaccination 1

Number of participants with solicited local AEs for 7 days after booster vaccination 1 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after booster vaccination 1 on Day 239 (Day 246)

Cohort 2b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Booster Vaccination 2

Number of participants with solicited local AEs for 7 days after booster Vaccination 2 in Cohort 2b were reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after booster vaccination 2 on Day 422 (Day 429)

Cohort 2b: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited local AEs for 7 days after ad hoc booster vaccination in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, are used to assess the reactogenicity of the study vaccine and are pre-defined local (injection site).

Time frame: 7 days after ad hoc booster vaccination (Day 369 up to Day 412)

Cohorts 1a and 1b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 1 in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after vaccination 1 on Day 1 (Day 8)

Cohorts 1a and 1b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 2 in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after Vaccination 2 on Day 57 (Day 64)

Cohorts 1a and 1b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited systemic AEs for 7 days after ad hoc booster vaccination in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post Ad Hoc Booster Vaccination (day of Ad hoc booster vaccination and the subsequent 7 days).

Time frame: 7 days after ad hoc booster vaccination (Day 488 up to Day 604)

Cohorts 2a and 2b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 1 in Cohorts 2a and 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after Vaccination 1 on Day 1 (Day 8)

Cohort 2a: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Booster Vaccination 1

Number of participants with solicited systemic AEs for 7 days post booster vaccination 1 in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after booster vaccination 1 on Day 183 (Day 190)

Cohort 2a: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Booster Vaccination 2

Number of participants with solicited systemic AEs for 7 days after booster vaccination 2 in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after booster vaccination 2 on Day 366 (Day 373)

Cohort 2a: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited systemic AEs for 7 days after ad hoc booster vaccination in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post adhoc booster vaccination (day of ad hoc booster vaccination and the subsequent 7 days).

Time frame: 7 days after ad hoc booster vaccination (Day 384 up to Day 451)

Cohort 2b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 2 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after Vaccination 2 on Day 57 (Day 64)

Cohort 2b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Booster Vaccination 1

Number of participants with solicited systemic AEs for 7 days after booster vaccination 1 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after booster vaccination 1 on Day 239 (Day 246)

Cohort 2b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Booster Vaccination 2

Number of participants with solicited systemic AEs for 7 days after booster vaccination 2 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days after booster vaccination 2 on Day 422 (Day 429)

Cohort 2b: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited systemic AEs for 7 days after ad hoc booster vaccination in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post ad hoc booster vaccination (day of ad hoc booster vaccination and the subsequent 7 days).

Time frame: 7 days after ad hoc booster vaccination (Day 369 up to Day 412)

Cohort 3: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after vaccination 1 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, were used to assess the reactogenicity of the study vaccine and were pre-defined local (injection site).

Time frame: 7 days after vaccination 1 on Day 1 (Day 8)

Cohort 3: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 1 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 1 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 days post-vaccination 1 on Day 1 (Day 8)

Cohort 3: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited local AEs for 7 days after vaccination 2 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, were used to assess the reactogenicity of the study vaccine and were pre-defined local (injection site).

Time frame: 7 days post-vaccination 2 on Day 57 (Day 64)

Cohort 3: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Vaccination 2 in the Primary Regimen

Number of participants with solicited systemic AEs for 7 days after vaccination 2 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post-vaccination (day of vaccination and the subsequent 7 days).

Time frame: 7 after post-vaccination 2 on Day 57 (Day 64)

Cohort 3: Number of Participants With Solicited Local (Injection Site) Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited local AEs for 7 days after ad hoc booster vaccination in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Solicited local (injection site) AEs that included injection site pain/tenderness, erythema and swelling at the study vaccine injection site, were used to assess the reactogenicity of the study vaccine and were pre-defined local (injection site).

Time frame: 7 days after ad hoc booster vaccination (Day 456 up to Day 711)

Cohort 3: Number of Participants With Solicited Systemic Adverse Events (AEs) for 7 Days After Ad Hoc Booster Vaccination

Number of participants with solicited systemic AEs for 7 days after ad hoc booster vaccination in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Systemic events included events such as fatigue, headache, nausea, and myalgia, for which participants were specifically questioned and which will be noted by participants in their participant diary for 7 days post ad hoc booster vaccination (day of ad hoc booster vaccination and the subsequent 7 days).

Time frame: 7 days after ad hoc booster vaccination (Day 456 up to Day 711)

Cohorts 1a and 1b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 1 in the Primary Regimen

Number of participants with unsolicited AEs after vaccination 1 in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after vaccination 1 on Day 1 (Day 29)

Cohorts 1a and 1b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 2 in the Primary Regimen

Number of participants with unsolicited AEs after vaccination 2 in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after vaccination 2 on Day 57 (Day 85)

Cohorts 1a and 1b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Ad Hoc Booster Vaccination

Number of participants with unsolicited AEs after ad hoc booster vaccination in Cohorts 1a and 1b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after ad hoc booster vaccination (Day 488 up to Day 625)

Cohorts 2a and 2b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 1 in the Primary Regimen

Number of participants with unsolicited AEs after vaccination 1 in Cohorts 2a and 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after Vaccination 1 on Day 1 (Day 29)

Cohort 2a: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Booster Vaccination 1

Number of participants with unsolicited AEs after booster 1 vaccination in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after booster vaccination 1 on Day 183 (Day 211)

Cohort 2a: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Booster Vaccination 2

Number of participants with unsolicited AEs after booster vaccination 2 in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after booster vaccination 2 on Day 366 (Day 394)

Cohort 2a: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Ad Hoc Booster Vaccination

Number of participants with unsolicited AEs after ad hoc booster vaccination in Cohort 2a were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after ad hoc booster vaccination (Day 384 up to Day 472)

Cohort 2b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 2 in the Primary Regimen

Number of participants with unsolicited AEs after vaccination 1 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after Vaccination 2 on Day 57 (Day 85)

Cohort 2b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Booster Vaccination 1

Number of participants with unsolicited AEs 28 days after booster vaccination 1 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after booster vaccination 1 on Day 239 (Day 267)

Cohort 2b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Booster Vaccination 2

Number of participants with unsolicited AEs 28 days after booster vaccination 2 in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after booster vaccination 2 on Day 422 (Day 450)

Cohort 2b: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Ad Hoc Booster Vaccination

Number of participants with unsolicited AEs 28 days after ad hoc booster vaccination in Cohort 2b were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after ad hoc booster vaccination (Day 369 up to Day 433)

Cohort 3: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 1 in the Primary Regimen

Number of participants with unsolicited AEs 28 days after vaccination 1 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after vaccination 1 on Day 1 (Day 29)

Cohort 3: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Vaccination 2 in the Primary Regimen

Number of participants with unsolicited AEs 28 days after vaccination 2 in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after vaccination 2 on Day 57 (Day 85)

Cohort 3: Number of Participants With Unsolicited Adverse Events (AEs) for 28 Days After Ad Hoc Booster Vaccination

Number of participants with unsolicited AEs 28 days after ad hoc booster vaccination in Cohort 3 were reported. An AE was any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. Unsolicited AEs were all AEs for which the participant is not specifically questioned in the participant diary.

Time frame: 28 days after ad hoc booster vaccination (Day 456 up to Day 732)

Cohorts 1a and 1b and Cohort 3: Number of Participants With Serious Adverse Events (SAEs)

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important.

Time frame: Day 1 up to 2 years after Vaccination 2 on Day 57 (Day 787)

Cohorts 2a and 2b: Number of Participants With Serious Adverse Events (SAEs)

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study. An SAE is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect; suspected transmission of any infectious agent via a medicinal product or medically important.

Time frame: Day 1 up to 6 months post primary regimen (up to Day 183 for Cohort 2a; up to Day 239 for Cohort 2b)

Cohorts 1a, 1b and 3: Number of Participants With Adverse Events of Special Interest (AESIs)

Number of participants with AESIs was reported. AESIs were significant AEs that were judged to be of special interest because of clinical importance, known or suspected class effects, or based on nonclinical signals. Thrombosis with Thrombocytopenia Syndrome (TTS), a syndrome characterized by a combination of both a thrombotic event and thrombocytopenia, was considered to be an AESI in this study. A suspected TTS case was defined as: Thrombotic events: suspected deep vessel venous or arterial thrombotic events; Thrombocytopenia, defined as platelet count below 150,000/microliter.

Time frame: Day 1 up to 2 years after Vaccination 2 on Day 57 (Day 787)

Cohorts 2a and 2b: Number of Participants With Adverse Events of Special Interest (AESIs)

Number of participants with AESIs was reported. AESIs were significant AEs that were judged to be of special interest because of clinical importance, known or suspected class effects, or based on nonclinical signals. Thrombosis with Thrombocytopenia Syndrome (TTS), a syndrome characterized by a combination of both a thrombotic event and thrombocytopenia, was considered to be an AESI in this study. A suspected TTS case was defined as: Thrombotic events: suspected deep vessel venous or arterial thrombotic events; Thrombocytopenia, defined as platelet count below 150,000/microliter.

Time frame: Day 1 up to 6 months post primary regimen (up to Day 183 for Cohort 2a; up to Day 239 for Cohort 2b)