Tick-Borne EncephalitisPhase 3NCT04648241

Study to Evaluate the Immunogenicity, Safety, and Tolerability of a Tick-Borne Encephalitis (TBE) Vaccine in Healthy Japanese Participants 1 Year of Age and Older

A Phase 3 study testing TBE vaccine 0.5 mL and TBE vaccine 0.25 mL in people with Tick-Borne Encephalitis, run by Pfizer at 6 sites in Japan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The main purpose of this study is to provide safety and immunogenicity data in Japanese participants. Read more about this study

Who is it for?: Ages 1 year and olderHealthy volunteers can take part
Conditions the study is for: Tick-Borne Encephalitis
What is being tested?: TBE vaccine 0.5 mL and TBE vaccine 0.25 mL
Type of treatment: Vaccines, Injection or infusion
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 165 participants
Where: 6 sitesJapan
Study dates: 18 Jan 2021to 21 Feb 2022
Phase: Phase 3
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 1 year and older
All sexes
Healthy volunteers accepted
Child, Adult, Older adult

Who may be able to join

Japanese male or female participants ≥1 years old at Visit 1.
Participants and/or a legally acceptable representative/parent/legal guardian are willing and able to comply with all scheduled visits, vaccination plan, and other study procedures including completion of the e-diary for 7 days for participants after each of 3 vaccinations.
Participants and/or a legally acceptable representative/parent/legal guardian must be able to be contacted by telephone during study participation.
Participants and/or a legally acceptable representative/parent/legal guardian are capable of giving signed informed consent.

Who cannot join

Major known congenital malformation or serious chronic disorder.
Known history of TBEV infection.
Known history of other flavivirus infection (eg, dengue fever, yellow fever, JEV, West Nile virus).
Known history of infection with HIV, HCV, or HBV.
Immunocompromised participants with known or suspected immunodeficiency.
History of autoimmune disease or an active autoimmune disease requiring therapeutic intervention.
Previous vaccination with any licensed or investigational TBE vaccine, or planned receipt of other flavivirus vaccines apart from JEV vaccine (eg, yellow fever, dengue fever) during the study. Administration of JEV vaccine is prohibited during participation.

Trial locations and contacts

6 sites in 1 country.

City, postcode or hospital

6 sites in 1 country

Japan6 sites

Azuma kodomo katei clinic
Ebetsu Shi, Hokkaido, 069-0816
Medical Co. LTA PS Clinic
Fukuoka, Fukuoka, 812-0025
Childrens clinic of Kose
Kofu, Yamanashi, 400-0853
Watanabe Pediatric Allergy Clinic
Sapporo, Hokkaido, 006-0831
Ohigesenseino Kodomo Clinic
Sapporo, Hokkaido, 062-0907
SUZURAN Children's Clinic
Sapporo, Hokkaido, 063-0841

Other trials in Japan

About this study

Official title: A PHASE 3, SINGLE-ARM, OPEN-LABEL STUDY TO EVALUATE THE IMMUNOGENICITY, SAFETY, AND TOLERABILITY OF A TICK-BORNE ENCEPHALITIS VACCINE IN HEALTHY JAPANESE PARTICIPANTS 1 YEAR OF AGE AND OLDER

The main purpose of this study is to provide safety and immunogenicity data in Japanese participants.

Conditions: Tick-Borne Encephalitis
Being tested: TBE vaccine 0.5 mL, TBE vaccine 0.25 mL
Medical subject headings: Encephalitis, Tick-Borne

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

TBE vaccine 0.5 mLBiological
TBE vaccine 0.5 mL (intramuscular injection).
TBE vaccine 0.25 mLBiological
TBE vaccine 0.25 mL (intramuscular injection).

Study groups in NCT04648241
Study group	Role	What they receive
≥16 Years Old	Experimental	TBE vaccine 0.5 mL (intramuscular injection). Receives: Biological: TBE vaccine 0.5 mL
1 to <16 Years Old	Experimental	TBE vaccine 0.25ｍL (intramuscular injection). Receives: Biological: TBE vaccine 0.25 mL

What is being measured

The primary outcome is the main question the study is designed to answer.

Percentage of Seropositive Participants at 4 Weeks After Dose 3
Seropositivity rate based on the immune response was determined by neutralization test (NT). Participants who achieved tick-borne encephalitis virus (TBEV) NT titers >=1: 10 were considered as seropositive. Exact 2-sided 95% confidence interval (CI) based on the Clopper and Pearson method was presented.
Measured: 4 weeks after Dose 3
Percentage of Participants With Local Reactions (LR) Within 7 Days After Dose 1
LR:participant or legally acceptable representative/parent/legal guardian using an electronic diary (e-diary). LR included redness, swelling and pain at injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 centimeter(cm). Redness and swelling were graded as: for participants >=12 years of age, mild(greater than[>] 2.0 to 5.0 cm), moderate(>5.0 to 10.0 cm) and severe (>10.0 cm); for participants less than (<)12 years of age, mild(>0 to 2.0 cm), moderate(>2.0 to7.0 cm) and severe(>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild(does not interfere with activity), moderate(interferes with activity) and severe(prevents daily activity); for participants less than or equal to (<=)2 years of age, mild(hurts if gently touched) moderate(hurts if gently touched with crying) and severe(causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 7 days after Dose 1
Percentage of Participants With Local Reactions Within 7 Days After Dose 2
Local reactions were collected by participant or legally acceptable representative/parent/legal guardian using an e-diary. Local reactions included redness, swelling and pain at the injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 cm. Redness and swelling were graded as: for participants >=12 years of age, mild (> 2.0 to 5.0 cm), moderate (>5.0 to 10.0 cm) and severe (>10.0 cm); for participants <12 years of age, mild (>0 to 2.0 cm), moderate (>2.0 to 7.0 cm) and severe (>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild (does not interfere with activity), moderate (interferes with activity) and severe (prevents daily activity); for participants <=2 years of age, mild (hurts if gently touched) moderate (hurts if gently touched with crying) and severe (causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 7 days after Dose 2
Percentage of Participants With Local Reactions Within 7 Days After Dose 3
Local reactions were collected by participant or legally acceptable representative/parent/legal guardian using an e-diary. Local reactions included redness, swelling and pain at the injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 cm. Redness and swelling were graded as: for participants >=12 years of age, mild (> 2.0 to 5.0 cm), moderate (>5.0 to 10.0 cm) and severe (>10.0 cm); for participants <12 years of age, mild (>0 to 2.0 cm), moderate (>2.0 to 7.0 cm) and severe (>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild (does not interfere with activity), moderate (interferes with activity) and severe (prevents daily activity); for participants <=2 years of age, mild (hurts if gently touched) moderate (hurts if gently touched with crying) and severe (causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 7 days after Dose 3
Percentage of Participants With Systemic Events (SE) Within 7 Days After Dose 1
SE:participants or legally acceptable representative/parent/legal guardian using e-diary \& included fever:temperature >=37.5 degree Celsius(C)\&categorized as 37.5to38.4, 38.5 to 38.9,39.0 to 40.0,>40.0 degree C.Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity), moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs), severe(required intravenous hydration). Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite:mild(decreased interest in eating),moderate(decreased oral intake), severe(refusal to feed).Drowsiness: mild(Increased sleeping bouts),moderate(slightly subdued interfering with daily activity),severe(disabling not interested in usual daily activity).Irritability:mild(easily consolable), moderate(required increased attention),severe(inconsolable, crying can't be comforted).
Measured: Within 7 days after Dose 1
Percentage of Participants With Systemic Events Within 7 Days After Dose 2
SE:participants or a legally acceptable representative/parent/legal guardian using e-diary and included fever:temperature >=37.5 degreeC \& categorized as 37.5 to 38.4,38.5 to 38.9,39.0 to 40.0,>40.0 degreeC.Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity),moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs),severe(required intravenous hydration).Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite: mild(decreased interest in eating), moderate(decreased oral intake), severe(refusal to feed). Drowsiness: mild(Increased sleeping bouts), moderate(slightly subdued interfering with daily activity), severe(disabling not interested in usual daily activity).Irritability: mild(easily consolable), moderate(required increased attention),severe(inconsolable, crying can't be comforted).
Measured: Within 7 days after Dose 2
Percentage of Participants With Systemic Events Within 7 Days After Dose 3
Systemic events collected by participant using e-diary and included fever defined as temperature >=37.5 degree C and categorized as 37.5 to 38.4, 38.5 to 38.9, 39.0 to 40.0, >40.0 degree C. Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity), moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs), severe(required intravenous hydration). Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite: mild(decreased interest in eating), moderate(decreased oral intake), severe(refusal to feed). Drowsiness: mild(Increased sleeping bouts), moderate(slightly subdued interfering with daily activity), severe(disabling not interested in usual daily activity). Irritability: mild(easily consolable), moderate(required increased attention), severe(inconsolable, crying can't be comforted).
Measured: Within 7 days after Dose 3
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 1
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 1 month after Dose 1
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 2
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 1 month after Dose 2
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 3
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 1 month after Dose 3
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Any Dose
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Within 1 month after any Dose
Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study
An SAE was defined as any untoward medical occurrence that, at any dose that resulted in death; was life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/incapacity (substantial disruption of the ability to conduct normal life functions); resulted in congenital anomaly/birth defect or that is considered to be an important medical event. Percentage of participants with SAEs and the exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: From Day 1 up to end of study (up to approximately 13 months)

Secondary outcomes (6)

Percentage of Seropositive Participants at 4 Weeks After Dose 2
Seropositivity rate based on the immune response was determined by NT. Participants who achieved TBEV NT titers >=1: 10 were considered as seropositive. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: 4 weeks after Dose 2
Geometric Mean Titers (GMTs) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 2 and Dose 3
GMTs and associated 2-sided 95% CIs were calculated as the mean of the assay results on the natural logarithmic scale based on Student's t distribution and then exponentiating the results. The lower limit of quantitation (LLOQ) value for NT was 5. Assay results below the LLOQ were set to 0.5 × LLOQ.
Measured: 4 weeks after Dose 2 and Dose 3
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 2 as Compared to Baseline
GMFRs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). The LLOQ value for NT was 5. Assay results below the LLOQ were set to 0.5 × LLOQ.
Measured: From Baseline to 4 weeks after Dose 2
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 3 as Compared to Baseline
GMFRs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). The LLOQ value for NT was 5. Assay results below the LLOQ were set to 0.5 × LLOQ.
Measured: From Baseline to 4 weeks after Dose 3
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 3 as Compared to 4 Weeks After Dose 2
GMFRs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). The LLOQ value for NT was 5. Assay results below the LLOQ were set to 0.5 × LLOQ.
Measured: From 4 weeks after Dose 2 to 4 weeks after Dose 3
Percentage of Participants With Neutralizing Antibody Titers >= Lower Limit of Quantification (LLOQ)
The LLOQ value for NT was 5. Assay results below the LLOQ were set to 0.5 × LLOQ. Percentage of participants with NT>=LLOQ and exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Measured: Before Dose 1, 4 weeks after Dose 2, Before Dose 3 and 4 weeks after Dose 3

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

18 Jan 202121 Feb 2022

First posted1 Dec 2020
Study start18 Jan 2021
Primary completion21 Feb 2022
Study completion21 Feb 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Tick-Borne EncephalitisStudies of the same condition, open and under way.
More trials run by PfizerThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 3
Primary purpose: Prevention
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 165 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04648241
Sponsor's protocol ID: B9371039
Status last verified: Feb 2023
First submitted: 9 Nov 2020
Last updated: 22 Nov 2023
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Publications

Yonekawa M, Watanabe T, Kogawara O, Yoshii C, Yamaji M, Aizawa M, Erber W, Ito S, Jug B, Koelch D, de Solom R, Lockhart SP. Phase 3 immunogenicity and safety study of a tick-borne encephalitis vaccine in healthy Japanese participants 1 year of age and older. Vaccine. 2024 May 10;42(13):3180-3189. doi: 10.1016/j.vaccine.2024.03.071. Epub 2024 Apr 12.
PubMed 38614954

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Tick-Borne Encephalitis trials

Study at a glance

From the registry record, last updated by the sponsor on 22 Nov 2023. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A PHASE 3, SINGLE-ARM, OPEN-LABEL STUDY TO EVALUATE THE IMMUNOGENICITY, SAFETY, AND TOLERABILITY OF A TICK-BORNE ENCEPHALITIS VACCINE IN HEALTHY JAPANESE PARTICIPANTS 1 YEAR OF AGE AND OLDER
ClinicalTrials.gov ID: NCT04648241
Acronym / sponsor ID: B9371039
Conditions: Tick-Borne Encephalitis
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 165 participants (actual)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Study start: 18 Jan 2021 (actual)
Primary completion: 21 Feb 2022 (actual)
Study completion: 21 Feb 2022 (actual)
First posted: 1 Dec 2020 (actual)
Results: Posted 22 Nov 2023

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

The main purpose of this study is to provide safety and immunogenicity data in Japanese participants.

Study design

Primary purpose: Prevention
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
≥16 Years Old	Experimental	Biological: TBE vaccine 0.5 mLTBE vaccine 0.5 mL (intramuscular injection).
1 to <16 Years Old	Experimental	Biological: TBE vaccine 0.25 mLTBE vaccine 0.25ｍL (intramuscular injection).

Who may qualify

Ages: 1 year and older
Sex: All
Healthy volunteers: Accepted
Age groups: Child, Adult, Older adult

Key inclusion criteria (4 listed)

Japanese male or female participants ≥1 years old at Visit 1.
Participants and/or a legally acceptable representative/parent/legal guardian are willing and able to comply with all scheduled visits, vaccination plan, and other study procedures including completion of the e-diary for 7 days for participants after each of 3 vaccinations.
Participants and/or a legally acceptable representative/parent/legal guardian must be able to be contacted by telephone during study participation.
Participants and/or a legally acceptable representative/parent/legal guardian are capable of giving signed informed consent.

Key exclusion criteria (7 listed)

Major known congenital malformation or serious chronic disorder.
Known history of TBEV infection.
Known history of other flavivirus infection (eg, dengue fever, yellow fever, JEV, West Nile virus).
Known history of infection with HIV, HCV, or HBV.
Immunocompromised participants with known or suspected immunodeficiency.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
TBE vaccine 0.5 mLTBE vaccine 0.5 mL (intramuscular injection).	Biological	≥16 Years Old
TBE vaccine 0.25 mLTBE vaccine 0.25 mL (intramuscular injection).	Biological	1 to <16 Years Old

Primary outcome

Percentage of Seropositive Participants at 4 Weeks After Dose 3
Time frame: 4 weeks after Dose 3
Seropositivity rate based on the immune response was determined by neutralization test (NT). Participants who achieved tick-borne encephalitis virus (TBEV) NT titers >=1: 10 were considered as seropositive. Exact 2-sided 95% confidence interval (CI) based on the Clopper and Pearson method was presented.
Percentage of Participants With Local Reactions (LR) Within 7 Days After Dose 1
Time frame: Within 7 days after Dose 1
LR:participant or legally acceptable representative/parent/legal guardian using an electronic diary (e-diary). LR included redness, swelling and pain at injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 centimeter(cm). Redness and swelling were graded as: for participants >=12 years of age, mild(greater than[>] 2.0 to 5.0 cm), moderate(>5.0 to 10.0 cm) and severe (>10.0 cm); for participants less than (<)12 years of age, mild(>0 to 2.0 cm), moderate(>2.0 to7.0 cm) and severe(>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild(does not interfere with activity), moderate(interferes with activity) and severe(prevents daily activity); for participants less than or equal to (<=)2 years of age, mild(hurts if gently touched) moderate(hurts if gently touched with crying) and severe(causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Local Reactions Within 7 Days After Dose 2
Time frame: Within 7 days after Dose 2
Local reactions were collected by participant or legally acceptable representative/parent/legal guardian using an e-diary. Local reactions included redness, swelling and pain at the injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 cm. Redness and swelling were graded as: for participants >=12 years of age, mild (> 2.0 to 5.0 cm), moderate (>5.0 to 10.0 cm) and severe (>10.0 cm); for participants <12 years of age, mild (>0 to 2.0 cm), moderate (>2.0 to 7.0 cm) and severe (>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild (does not interfere with activity), moderate (interferes with activity) and severe (prevents daily activity); for participants <=2 years of age, mild (hurts if gently touched) moderate (hurts if gently touched with crying) and severe (causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Local Reactions Within 7 Days After Dose 3
Time frame: Within 7 days after Dose 3
Local reactions were collected by participant or legally acceptable representative/parent/legal guardian using an e-diary. Local reactions included redness, swelling and pain at the injection site. Redness and swelling were measured using measuring device units. 1 measuring device unit =0.5 cm. Redness and swelling were graded as: for participants >=12 years of age, mild (> 2.0 to 5.0 cm), moderate (>5.0 to 10.0 cm) and severe (>10.0 cm); for participants <12 years of age, mild (>0 to 2.0 cm), moderate (>2.0 to 7.0 cm) and severe (>7.0 cm). Pain at the injection site was graded as: for participants >2 years of age, mild (does not interfere with activity), moderate (interferes with activity) and severe (prevents daily activity); for participants <=2 years of age, mild (hurts if gently touched) moderate (hurts if gently touched with crying) and severe (causes limitation of limb movement). Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Systemic Events (SE) Within 7 Days After Dose 1
Time frame: Within 7 days after Dose 1
SE:participants or legally acceptable representative/parent/legal guardian using e-diary \& included fever:temperature >=37.5 degree Celsius(C)\&categorized as 37.5to38.4, 38.5 to 38.9,39.0 to 40.0,>40.0 degree C.Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity), moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs), severe(required intravenous hydration). Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite:mild(decreased interest in eating),moderate(decreased oral intake), severe(refusal to feed).Drowsiness: mild(Increased sleeping bouts),moderate(slightly subdued interfering with daily activity),severe(disabling not interested in usual daily activity).Irritability:mild(easily consolable), moderate(required increased attention),severe(inconsolable, crying can't be comforted).
Percentage of Participants With Systemic Events Within 7 Days After Dose 2
Time frame: Within 7 days after Dose 2
SE:participants or a legally acceptable representative/parent/legal guardian using e-diary and included fever:temperature >=37.5 degreeC \& categorized as 37.5 to 38.4,38.5 to 38.9,39.0 to 40.0,>40.0 degreeC.Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity),moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs),severe(required intravenous hydration).Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite: mild(decreased interest in eating), moderate(decreased oral intake), severe(refusal to feed). Drowsiness: mild(Increased sleeping bouts), moderate(slightly subdued interfering with daily activity), severe(disabling not interested in usual daily activity).Irritability: mild(easily consolable), moderate(required increased attention),severe(inconsolable, crying can't be comforted).
Percentage of Participants With Systemic Events Within 7 Days After Dose 3
Time frame: Within 7 days after Dose 3
Systemic events collected by participant using e-diary and included fever defined as temperature >=37.5 degree C and categorized as 37.5 to 38.4, 38.5 to 38.9, 39.0 to 40.0, >40.0 degree C. Fatigue, headache, muscle pain, joint pain: mild(didn't interfere with activity), moderate(some interference with activity), severe(prevented daily activity). Vomiting: mild(1-2 times in 24 hours[hrs]), moderate(>2 times in 24hrs), severe(required intravenous hydration). Diarrhea: mild(2-3 loose stools in 24hrs), moderate(4-5 loose stools in 24hrs), severe(6 or more loose stools in 24hrs). Decreased appetite: mild(decreased interest in eating), moderate(decreased oral intake), severe(refusal to feed). Drowsiness: mild(Increased sleeping bouts), moderate(slightly subdued interfering with daily activity), severe(disabling not interested in usual daily activity). Irritability: mild(easily consolable), moderate(required increased attention), severe(inconsolable, crying can't be comforted).
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 1
Time frame: Within 1 month after Dose 1
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 2
Time frame: Within 1 month after Dose 2
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Dose 3
Time frame: Within 1 month after Dose 3
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Any Dose
Time frame: Within 1 month after any Dose
An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention. Exact 2-sided 95% CI based on the Clopper and Pearson method was presented.
Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study
Time frame: From Day 1 up to end of study (up to approximately 13 months)
An SAE was defined as any untoward medical occurrence that, at any dose that resulted in death; was life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/incapacity (substantial disruption of the ability to conduct normal life functions); resulted in congenital anomaly/birth defect or that is considered to be an important medical event. Percentage of participants with SAEs and the exact 2-sided 95% CI based on the Clopper and Pearson method was presented.

6 secondary outcomes

Percentage of Seropositive Participants at 4 Weeks After Dose 2
Time frame: 4 weeks after Dose 2
Geometric Mean Titers (GMTs) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 2 and Dose 3
Time frame: 4 weeks after Dose 2 and Dose 3
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 2 as Compared to Baseline
Time frame: From Baseline to 4 weeks after Dose 2
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 3 as Compared to Baseline
Time frame: From Baseline to 4 weeks after Dose 3
Geometric Mean Fold Rise (GMFR) of TBEV Neutralizing Antibody Titers at 4 Weeks After Dose 3 as Compared to 4 Weeks After Dose 2
Time frame: From 4 weeks after Dose 2 to 4 weeks after Dose 3
Percentage of Participants With Neutralizing Antibody Titers >= Lower Limit of Quantification (LLOQ)
Time frame: Before Dose 1, 4 weeks after Dose 2, Before Dose 3 and 4 weeks after Dose 3

Results and safety

Results posted to the registry on 22 Nov 2023, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Adults (>=16 Years Old)	100	99
Pediatric (1 to <16 Years Old)	65	65

Primary outcome: Percentage of Seropositive Participants at 4 Weeks After Dose 3

Time frame: 4 weeks after Dose 3. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	Adults (>=16 Years Old) n = 99	Pediatric (1 to <16 Years Old) n = 65
Value	98.0 (92.9 to 99.8)	100 (94.5 to 100)

Population analysed: Evaluable immunogenicity (EI) population: Participants who received all 3 doses of the investigational product, had blood drawn for assay testing within the specified time frame for baseline and 4 weeks after the third vaccination, had valid and determinate assay result (NT titer) at baseline and 4 weeks after the third vaccination visit, were NT seronegative at baseline, and had no major protocol violations.

Primary outcome: Percentage of Participants With Local Reactions (LR) Within 7 Days After Dose 1

Time frame: Within 7 days after Dose 1. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	Adults (>=16 Years Old) n = 100	Pediatric (1 to <16 Years Old) n = 65
Redness: Mild	2.0 (0.2 to 7.0)	3.1 (0.4 to 10.7)
Redness: Moderate	0 (0.0 to 3.6)	1.5 (0.0 to 8.3)
Redness: Severe	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Swelling: Mild	3.0 (0.6 to 8.5)	3.1 (0.4 to 10.7)
Swelling: Moderate	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Swelling: Severe	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Pain at the injection site: Mild	52.0 (41.8 to 62.1)	36.9 (25.3 to 49.8)
Pain at the injection site: Moderate	7.0 (2.9 to 13.9)	6.2 (1.7 to 15.0)

Population analysed: Safety analysis population included all enrolled participants who received at least 1 dose of the investigational product.

Primary outcome: Percentage of Participants With Local Reactions Within 7 Days After Dose 2

Time frame: Within 7 days after Dose 2. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	Adults (>=16 Years Old) n = 100	Pediatric (1 to <16 Years Old) n = 65
Redness: Mild	0.0 (0.0 to 3.6)	3.1 (0.4 to 10.7)
Redness: Moderate	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Redness: Severe	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Swelling: Mild	0 (0.0 to 3.6)	1.5 (0.0 to 8.3)
Swelling: Moderate	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Swelling: Severe	0 (0.0 to 3.6)	0 (0.0 to 5.5)
Pain at the injection site: Mild	40.0 (30.3 to 50.3)	24.6 (14.8 to 36.9)
Pain at the injection site: Moderate	4.0 (1.1 to 9.9)	1.5 (0.0 to 8.3)

Population analysed: Safety analysis population included all enrolled participants who received at least 1 dose of the investigational product.

Primary outcome: Percentage of Participants With Local Reactions Within 7 Days After Dose 3

Time frame: Within 7 days after Dose 3. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	Adults (>=16 Years Old) n = 99	Pediatric (1 to <16 Years Old) n = 65
Redness: Mild	2.0 (0.2 to 7.1)	7.7 (2.5 to 17.0)
Redness: Moderate	0 (0.0 to 3.7)	0 (0.0 to 5.5)
Redness: Severe	0 (0.0 to 3.7)	0 (0.0 to 5.5)
Swelling: Mild	1.0 (0.0 to 5.5)	6.2 (1.7 to 15.0)
Swelling: Moderate	1.0 (0.0 to 5.5)	3.1 (0.4 to 10.7)
Swelling: Severe	0 (0.0 to 3.7)	0 (0.0 to 5.5)
Pain at the injection site: Mild	33.3 (24.2 to 43.5)	30.8 (19.9 to 43.4)
Pain at the injection site: Moderate	3.0 (0.6 to 8.6)	4.6 (1.0 to 12.9)

Population analysed: Safety analysis population included all enrolled participants who received at least 1 dose of the investigational product. Here, "Overall Number of Participants Analyzed" signifies participants who were evaluable for this outcome measure.

6 secondary outcomes are reported in the full results.

Adverse events

Time frame: All-Cause mortality and SAEs: from Day 1 up to end of study (up to approximately 13 months); Other AEs (non-systematic assessment): up to 1 month after each Dose; Local reactions and systemic events (systematic assessment, included in other AEs): within 7 days after each Dose. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Adults (>=16 Years Old)	2 of 100 (2%)	76 of 100 (76%)	0 of 100
Pediatric (1 to <16 Years Old)	1 of 65 (1.5%)	59 of 65 (90.8%)	0 of 65

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 22 Nov 2023.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 38614954Yonekawa M, Watanabe T, Kogawara O, Yoshii C, Yamaji M, Aizawa M, Erber W, Ito S, Jug B, Koelch D, de Solom R, Lockhart SP. Phase 3 immunogenicity and safety study of a tick-borne encephalitis vaccine in healthy Japanese participants 1 year of age and older. Vaccine. 2024 May 10;42(13):3180-3189. doi: 10.1016/j.vaccine.2024.03.071. Epub 2024 Apr 12.
To obtain contact information for a study center near you, click here.Link provided by the sponsor.
Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Pfizer CT.gov Call Center study director

Pfizer

6 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing TBE vaccine 0.5 mL and TBE vaccine 0.25 mL in people with Tick-Borne Encephalitis, run by Pfizer at 6 sites in Japan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 22 Nov 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in Japan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 22 Nov 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Percentage of Seropositive Participants at 4 Weeks After Dose 3 (time frame: 4 weeks after Dose 3). The study lists 12 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04648241, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Nov 2023.