Trial Outcomes & Findings for Safety, Tolerability, and Immunogenicity of Vaxelis™ in Children Previously Vaccinated With Vaxelis™ or Hexyon™ (V419-016) (NCT NCT05289271)

NCT ID: NCT05289271

Last Updated: 2024-07-29

Results Overview

Solicited injection-site AEs are predefined local (at the injection/administration site) events for which the participant's legally authorized representative was specifically questioned. Participant's legally acceptable representative used a Vaccination Report Card (VRC) to report the following solicited injection-site AEs : swelling, redness (erythema), and pain/tenderness. 95% confidence intervals (CIs) were calculated based on the exact binomial method proposed by Clopper and Pearson.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

168 participants

Primary outcome timeframe

Up to 5 days postvaccination

Results posted on

2024-07-29

Participant Flow

Healthy participants approximately 11 to 13 months of age, (≥327 days to ≤396 days inclusive).were enrolled in this study.

Participant milestones

Participant milestones
Measure
Group 1: V, V, V
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Overall Study
STARTED
86
82
Overall Study
Treated
85
82
Overall Study
COMPLETED
85
82
Overall Study
NOT COMPLETED
1
0

Reasons for withdrawal

Reasons for withdrawal
Measure
Group 1: V, V, V
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Overall Study
Mistakenly allocated, untreated
1
0

Baseline Characteristics

Safety, Tolerability, and Immunogenicity of Vaxelis™ in Children Previously Vaccinated With Vaxelis™ or Hexyon™ (V419-016)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Group 1: V, V, V
n=86 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Total
n=168 Participants
Total of all reporting groups
Age, Continuous
348.8 Days
STANDARD_DEVIATION 18.8 • n=99 Participants
344.7 Days
STANDARD_DEVIATION 16.4 • n=107 Participants
346.8 Days
STANDARD_DEVIATION 17.7 • n=206 Participants
Sex: Female, Male
Female
44 Participants
n=99 Participants
33 Participants
n=107 Participants
77 Participants
n=206 Participants
Sex: Female, Male
Male
42 Participants
n=99 Participants
49 Participants
n=107 Participants
91 Participants
n=206 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
45 Participants
n=99 Participants
60 Participants
n=107 Participants
105 Participants
n=206 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
34 Participants
n=99 Participants
21 Participants
n=107 Participants
55 Participants
n=206 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
7 Participants
n=99 Participants
1 Participants
n=107 Participants
8 Participants
n=206 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
Race (NIH/OMB)
Asian
1 Participants
n=99 Participants
0 Participants
n=107 Participants
1 Participants
n=206 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
Race (NIH/OMB)
White
85 Participants
n=99 Participants
82 Participants
n=107 Participants
167 Participants
n=206 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=99 Participants
0 Participants
n=107 Participants
0 Participants
n=206 Participants

PRIMARY outcome

Timeframe: Up to 5 days postvaccination

Population: All participants who received study vaccination.

Solicited injection-site AEs are predefined local (at the injection/administration site) events for which the participant's legally authorized representative was specifically questioned. Participant's legally acceptable representative used a Vaccination Report Card (VRC) to report the following solicited injection-site AEs : swelling, redness (erythema), and pain/tenderness. 95% confidence intervals (CIs) were calculated based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=85 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With a Solicited Injection-site Adverse Event (AE)
Injection site erythema
52.9 Percentage of participants
Interval 41.8 to 63.9
50.0 Percentage of participants
Interval 38.7 to 61.3
Percentage of Participants With a Solicited Injection-site Adverse Event (AE)
Injection site pain
74.1 Percentage of participants
Interval 63.5 to 83.0
56.1 Percentage of participants
Interval 44.7 to 67.0
Percentage of Participants With a Solicited Injection-site Adverse Event (AE)
Injection site swelling
52.9 Percentage of participants
Interval 41.8 to 63.9
40.2 Percentage of participants
Interval 29.6 to 51.7

PRIMARY outcome

Timeframe: Up to 5 days postvaccination

Population: All participants who received study vaccination.

Solicited systemic AE are predefined systemic events for which the participant's legally authorized representative was specifically questioned. Participant's legally acceptable representative used a VRC to report the following solicited systemic AEs: vomiting, drowsiness (somnolence), loss of appetite, and irritability. 95% CIs were calculated based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=85 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With a Solicited Systemic AE
Decreased appetite
43.5 Percentage of participants
Interval 32.8 to 54.7
36.6 Percentage of participants
Interval 26.2 to 48.0
Percentage of Participants With a Solicited Systemic AE
Irritability
77.6 Percentage of participants
Interval 67.3 to 86.0
58.5 Percentage of participants
Interval 47.1 to 69.3
Percentage of Participants With a Solicited Systemic AE
Somnolence
64.7 Percentage of participants
Interval 53.6 to 74.8
47.6 Percentage of participants
Interval 36.4 to 58.9
Percentage of Participants With a Solicited Systemic AE
Vomiting
3.5 Percentage of participants
Interval 0.7 to 10.0
8.5 Percentage of participants
Interval 3.5 to 16.8

PRIMARY outcome

Timeframe: Up to 15 days postvaccination

Population: All participants who received study vaccination.

An unsolicited AE is an AE that was not solicited using a VRC and that is communicated by a participant's legally authorized representative who has signed the informed consent. An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. 95% CIs were calculated based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=85 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Unsolicited AEs
97.6 Percentage of participants
Interval 91.8 to 99.7
92.7 Percentage of participants
Interval 84.8 to 97.3

PRIMARY outcome

Timeframe: Up to 40 days postvaccination

Population: All participants who received study vaccination.

An SAE is any untoward medical occurrence that results in death, is life-threatening, requires hospitalization or prolongs existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is another important medical event. 95% CIs were calculated based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=85 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With a Serious AE (SAE)
0.0 Percentage of participants
Interval 0.0 to 4.2
1.2 Percentage of participants
Interval 0.0 to 6.6

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to diphtheria toxoid were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with the lower limit of quantitation (LLOQ) for diphtheria antibody of 0.005 IU/mL. The percentage of participants with diphtheria toxoid antibodies ≥0.1 international units per milliliter (IU/mL) one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=69 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=74 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Diphtheria Toxoid Antibodies ≥0.1 IU/mL
100.0 Percentage of participants
Interval 94.8 to 100.0
98.6 Percentage of participants
Interval 92.7 to 100.0

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to tetanus toxoid were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with a LLOQ for tetanus antibody of 0.01 IU/mL. The percentage of participants with tetanus toxoid antibodies ≥0.1 IU/mL one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=69 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=74 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Tetanus Toxoid Antibodies ≥0.1 IU/mL
98.6 Percentage of participants
Interval 92.2 to 100.0
98.6 Percentage of participants
Interval 92.7 to 100.0

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to pertussis toxoid were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with a LLOQ for pertussis antibody of 2.00 EU/mL. The percentage of participants meeting response criteria for PT is based on pre-vaccination level of PT is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=64 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=71 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Pertussis Toxoid (PT) Vaccine Response
98.4 Percentage of participants
Interval 91.6 to 100.0
94.4 Percentage of participants
Interval 86.2 to 98.4

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to FHA were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with a LLOQ for FHA antibody of 2.00 EU/mL. The percentage of participants meeting response criteria for FHA response will be based on pre-vaccination level of FHA. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=64 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=71 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Filamentous Hemagglutinin (FHA) Vaccine Response
98.4 Percentage of participants
Interval 91.6 to 100.0
90.1 Percentage of participants
Interval 80.7 to 95.9

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to Hib-PRP were quantified using the Vacczyme™ Human Anti-Haemophilus influenzae Type b Enzyme Immunoassay Kit. Levels of anti-Hib IgG were quantified by interpolation from a standard curve that has been calibrated to the FDA lot 1983 reference serum. The percentage of participants with Hib-PRP antibodies ≥0.1 IU/mL one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=73 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=76 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Haemophilus Influenzae Type b Polyribosylribitol Phosphate (Hib-PRP) Antibodies ≥1.0 µg/mL
89.0 Percentage of participants
Interval 79.5 to 95.1
90.8 Percentage of participants
Interval 81.9 to 96.2

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to HBsAg were quantified using an Enhanced Chemiluminescence (ECi) assay, with the hepatitis B WHO International reference standard at 10 mIU/mL as a control in every assay, and the LLOQ of the assay is 5 mIU/mL. The percentage of participants with HBsAg antibodies ≥10 milli-international per liter (mIU/mL) one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=56 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=69 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Hepatitis B Surface Antigen (HBsAg) Antibodies ≥10 mIU/mL
100.0 Percentage of participants
Interval 93.6 to 100.0
94.2 Percentage of participants
Interval 85.8 to 98.4

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to poliovirus serotype 1 were quantified with a neutralization assay by utilizing Vero cells and wild type poliovirus strain 1 as the challenge virus. The Karber method was used to determine the serum dilution that neutralized 50% of the challenge virus, with results expressed as titers (1:dilution), and the LLOQ was 1:4. dilution. The percentage of participants with poliovirus serotype 1 Nab ≥1:8 dilution one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=66 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=69 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Poliovirus Serotype 1 Neutralizing Antibodies (Nab) ≥1:8 Dilution
100.0 Percentage of participants
Interval 94.6 to 100.0
95.7 Percentage of participants
Interval 87.8 to 99.1

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to poliovirus serotype 2 were quantified with a neutralization assay by utilizing Vero cells and wild type poliovirus strain 2 as the challenge virus. The Karber method was used to determine the serum dilution that neutralized 50% of the challenge virus, with results expressed as titers (1:dilution), and the LLOQ was 1:4. dilution. The percentage of participants with poliovirus serotype 2 Nab ≥1:8 dilution one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=66 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=69 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Poliovirus Serotype 2 Neutralizing Antibodies (Nab) ≥1:8 Dilution
100.0 Percentage of participants
Interval 94.6 to 100.0
100.0 Percentage of participants
Interval 94.8 to 100.0

PRIMARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to poliovirus serotype 3 were quantified with a neutralization assay by utilizing Vero cells and wild type poliovirus strain 3 as the challenge virus. The Karber method was used to determine the serum dilution that neutralized 50% of the challenge virus, with results expressed as titers (1:dilution), and the LLOQ was 1:4. dilution. The percentage of participants with poliovirus serotype 3 Nab ≥1:8 dilution one month after Vaxelis™ as the 3rd dose of a vaccination series is presented. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=66 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=69 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Poliovirus Serotype 3 Neutralizing Antibodies (Nab) ≥1:8 Dilution
97.0 Percentage of participants
Interval 89.5 to 99.6
100.0 Percentage of participants
Interval 94.8 to 100.0

SECONDARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to PRN were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with a LLOQ for PRN of 2.00 EU/mL.The percentage of participants meeting response criteria for PRN was based on pre-vaccination level of PRN. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=64 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=71 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Pertactin (PRN) Vaccine Response
92.2 Percentage of participants
Interval 82.7 to 97.4
22.5 Percentage of participants
Interval 13.5 to 34.0

SECONDARY outcome

Timeframe: 30 days postvaccination (at ~12 months of age)

Population: All enrolled participants without deviations from the protocol that may substantially affect the results of the immunogenicity endpoint. Potential deviations include, but are not limited to failure to receive study vaccine at Visit 1 (Day 1); receipt of a prohibited medication or prohibited vaccine within the study window; or collection of blood sample at Visit 2 outside the prespecified window (Day 26 to Day 40).

Human antibodies to FIM 2/3 were quantified using the Meso Scale Discovery Electrochemiluminescence serological assay based on an established reference standard sample curve with a LLOQ for pertussis antibody of 2.00 EU/mL. The percentage of participants meeting response criteria for FIM 2/3 was based on pre-vaccination level of FIM 2/3. The 95% CIs are based on the exact binomial method proposed by Clopper and Pearson.

Outcome measures

Outcome measures
Measure
Group 1: V, V, V
n=64 Participants
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=71 Participants
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Percentage of Participants With Fimbriae 2/3 (FIM 2/3) Vaccine Response
95.3 Percentage of participants
Interval 86.9 to 99.0
69.0 Percentage of participants
Interval 56.9 to 79.5

Adverse Events

Group 1: V, V, V

Serious events: 0 serious events
Other events: 83 other events
Deaths: 0 deaths

Group 2: H, H, V

Serious events: 1 serious events
Other events: 75 other events
Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure
Group 1: V, V, V
n=85 participants at risk
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 participants at risk
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Infections and infestations
Gastroenteritis adenovirus
0.00%
0/85 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
1.2%
1/82 • Number of events 1 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.

Other adverse events

Other adverse events
Measure
Group 1: V, V, V
n=85 participants at risk
Participants who received a 2-dose regimen of Vaxelis™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Group 2: H, H, V
n=82 participants at risk
Participants who received a 2-dose regimen of Hexyon™ as infants prior to enrollment received a Vaxelis™ booster at \~11 months of age.
Gastrointestinal disorders
Diarrhoea
1.2%
1/85 • Number of events 1 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
7.3%
6/82 • Number of events 6 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
Gastrointestinal disorders
Vomiting
5.9%
5/85 • Number of events 5 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
9.8%
8/82 • Number of events 8 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
General disorders
Injection site erythema
52.9%
45/85 • Number of events 45 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
50.0%
41/82 • Number of events 41 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
General disorders
Injection site induration
0.00%
0/85 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
7.3%
6/82 • Number of events 6 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
General disorders
Injection site pain
74.1%
63/85 • Number of events 63 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
56.1%
46/82 • Number of events 46 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
General disorders
Injection site swelling
52.9%
45/85 • Number of events 45 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
40.2%
33/82 • Number of events 33 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
General disorders
Pyrexia
40.0%
34/85 • Number of events 35 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
48.8%
40/82 • Number of events 47 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
Metabolism and nutrition disorders
Decreased appetite
43.5%
37/85 • Number of events 38 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
36.6%
30/82 • Number of events 31 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
Nervous system disorders
Somnolence
64.7%
55/85 • Number of events 55 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
47.6%
39/82 • Number of events 42 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
Psychiatric disorders
Irritability
77.6%
66/85 • Number of events 66 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.
58.5%
48/82 • Number of events 49 • Adverse events (AEs): from vaccination up to 40 days post-vaccination; All-cause mortality (ACM): From allocation up to 40 days post-vaccination
AE population: All participants who received study vaccination. ACM population: all allocated participants.

Additional Information

Senior Vice President, Global Clinical Development

Merck Sharp & Dohme LLC

Phone: 1-800-672-6372

Results disclosure agreements

  • Principal investigator is a sponsor employee If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. This allows the Sponsor to protect proprietary information and to provide comments.
  • Publication restrictions are in place

Restriction type: OTHER