Participants or their parents/guardians maintained a memory aid to record daily the occurrence of local reactions of pain, tenderness and swelling for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of local reactions of pain, tenderness and swelling for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of local reactions of swelling and redness for 8 days after vaccination (Day 0-7). If the reaction was present, the maximum diameter was measured in millimeters (mm). Participants are counted if they were reported as experiencing the reaction with any measurement greater than 0 mm on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of local reactions of swelling and redness for 8 days after vaccination (Day 0-7). If the reaction was present, the maximum diameter was measured in millimeters (mm). Participants are counted if they were reported as experiencing the reaction with any measurement greater than 0 mm on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

Participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the window are included. Two are excluded due to receipt of non-study vaccines, two due to vaccine administration errors and 1 due to a sample labeling error. Analyses are as treated. This outcome restricts to age stratum.

Participants or their parents/guardians maintained a memory aid to record daily oral/axillary temperatures and the number of vomiting episodes, if experienced, for 8 days after vaccination (Day 0-7). Participants are counted as experiencing fever if they reported oral temperatures of 38.3 degrees Celsius or higher, or axillary temperatures of 37.8 degrees Celsius or higher, on any of the 8 days. Participants are counted as experiencing vomiting if they reported one or more episodes of vomiting on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated.

Participants or their parents/guardians maintained a memory aid to record daily oral/axillary temperatures and the number of vomiting episodes, if experienced, for 8 days after vaccination (Day 0-7). Participants are counted as experiencing fever if they reported oral temperatures of 38.3 degrees Celsius or higher, or axillary temperatures of 37.8 degrees Celsius or higher, on any of the 8 days. Participants are counted as experiencing vomiting if they reported one or more episodes of vomiting on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated.

Participants' parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of irritability, decreased appetite and lethargy for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Participants' parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of irritability, decreased appetite and lethargy for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of feverishness, myalgia, headache, nausea and decreased general activity for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of feverishness, myalgia, headache, nausea and decreased general activity for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of feverishness, myalgia, headache, nausea, decreased general activity, and malaise for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Participants or their parents/guardians maintained a memory aid to record daily the occurrence of systemic symptoms of feverishness, myalgia, headache, nausea, decreased general activity, and malaise for 8 days after vaccination (Day 0-7) based on their interference with daily activities. Participants are counted if they were reported as experiencing the symptom at any severity on any of the 8 days.

All participants receiving the second vaccination are included in the safety cohort. Analyses are as treated. This outcome measure is restricted to protocol-defined age stratum.

Serious adverse events included any untoward medical occurrence that resulted in death; was life threatening; was a persistent/significant disability/incapacity; required in-patient hospitalization or prolongation thereof; resulted in a congenital anomaly/birth defect; or may have jeopardized the participant or required intervention to prevent one of these outcomes. Association to vaccination was determined by a study clinician licensed to make medical diagnoses.

All participants receiving the first vaccination are included in the safety cohort. Analyses are as treated.

Blood was collected from all participants prior to vaccination for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum, for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

Participants with blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum. One participant was excluded due to the Day 21 blood draw being greater than 7 days out of window.

Blood was collected from all participants prior to vaccination for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum, for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at the timepoint within 7 days of the visit window are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was collected from all participants prior to vaccination and at Days 8-10 and 21 for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants with blood collected at baseline and with at least one evaluable time point after vaccination are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 titer was an increase by 4-fold or more.

All participants with blood collected at both timepoints are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum, for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more.

Participants with blood collected at both timepoints are included. Analyses are as treated. This outcome restricts to age stratum. One participant was excluded due to the Day 21 blood draw being greater than 7 days out of window.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 titer was an increase by 4-fold or more.

All participants with blood collected at both timepoints are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum, for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more.

All participants with blood collected at both timepoints are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from all participants enrolled in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 or Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 or Day 21 titer was an increase by 4-fold or more.

All participants with blood collected at the timepoints are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

Participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the window are included. One participant is excluded due to vaccine administration error. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from all participants enrolled in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from all participants enrolled in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. Each sample was tested at least twice according to standard operating procedures and the result of each replicate reported. A participant is counted if the geometric mean of the replicate values was 1:40 or greater.

All participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the visit window are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 titer was an increase by 4-fold or more.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more.

Participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the visit window are included. Two are excluded due to receipt of non-study vaccines, two due to vaccine administration errors and 1 due to a sample labeling error. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 titer was an increase by 4-fold or more.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from participants enrolled after the first 30 in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more.

Participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the visit window are included. One participant is excluded due to vaccine administration error. Analyses are as treated. This outcome restricts to age stratum.

Blood was to be collected from the first 30 participants enrolled in each dose group in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 8-10 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 8-10 titer was an increase by 4-fold or more.

All participants who received the second vaccination within 7 days of the visit window and had blood collected at the timepoint are included. Analyses are as treated. This outcome restricts to age stratum.

Blood was collected from all participants enrolled in this age stratum for testing in the HAI assay with Influenza H1N1 2009 virus as the assay antigen. A participant met the threshold of a 4-fold rise in titer if the Day 0 titer was less than 1:10 (the assay's lowest level of detection) and the Day 21 titer was 1:40 or greater, or the Day 0 titer was greater than or equal to 1:10 and the Day 21 titer was an increase by 4-fold or more.

All participants who received the second vaccination and had blood collected at the timepoint both within 7 days of the visit window are included. Analyses are as treated. This outcome restricts to age stratum.