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CompletedNCT03769194Updated Jan 10, 2023Results posted

Immunogenicity and Safety Study of a Vaccine Against Lyme Borreliosis, in Healthy Adults Aged 18 to 65 Years. Randomized, Controlled, Observer-blind Phase 2 Study.

A Phase 2 interventional study of VLA15 and Placebo in Lyme Borreliosis, sponsored by Pfizer. Completed at 9 sites in 3 countries. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-01-10.

Sponsored by Pfizer · Phase 2, Interventional, and Prevention

Phase
Phase 2
Study type
Interventional
Enrollment
572
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

This is a randomized, observer-blind, placebo controlled, multicenter Phase 2 study conducted in two study phases: a run-in phase and a main study phase. The study was investigated 3 doses of a multivalent OspA (Outer Surface Protein A) based Lyme vaccine (VLA15) in healthy adults aged 18 to 65 years of age. Study participants received 3 immunizations of the vaccine at a monthly interval. The study assessed the immune response as well as the safety profile of the vaccine.

Read the detailed description

This is a randomized, observer-blind, placebo controlled, multicenter Phase 2 study.

In the Run-in phase, a total of 120 subjects aged 18 to 40 years were randomized 1:1:1:1 to receive one of three VLA15 doses (VLA15 low dose (90 µg), VLA15 medium dose (135 µg), VLA15 high dose (180 µg)) or Placebo as intramuscular vaccinations on Days 1, 29 and 57.

Dosing was adjusted by injection volume.

In the Main Study phase, a total of 452 subjects aged 18 to 65 years were randomized 2:2:1 to receive VLA15 135 µg or VLA15 180 µg, the two dose groups were selected from the Run-in-Phase or placebo, as intramuscular vaccinations on Days 1, 29 and 57. Subjects were enrolled in two age groups (18-49 years and 50-65 years) in a ratio of approx. 2:1.

In both study phases, target was to enroll approx. 10 % or more of subjects that were baseline seropositive for Borrelia burgdorferi sensu latu (Bb s.l.).

02

Conditions studied

  • Lyme Borreliosis

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Keywords

  • VLA15, Lyme Borreliosis, Vaccine
03

In context

Lyme Disease

91 studies on the registry are indexed under Lyme Disease; 27 are open to participants now.

This study's enrollment of 572 is above the median of 100 across 49 interventional studies indexed under Lyme Disease.

Browse Lyme Disease studies →

Lead sponsor

Pfizer is the lead sponsor of 3,244 studies on the registry; 139 are open to participants now.

Of its 582 completed or terminated interventional studies of FDA-regulated products, 381 (65%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

Run-in phase:

  1. Subject is aged 18 to 40 years at the day of screening (Visit 0);

Main Study phase:

  1. Subject is aged18 to 65 years at the day of screening (Visit 0);

    Run-in phase and Main Study phase:

  2. Subject is of good general health, including subjects with pharmacologically controlled chronic conditions;
  3. Subject has an understanding of the study and its procedures, agrees to its provisions, and gives written informed consent prior to any study-related procedures;

  4. If subject is of childbearing potential:

    1. Subject has a negative serum pregnancy test at screening (Visit 0);
    2. Subject agrees to employ adequate birth control measures for the duration of the study.

Exclusion criteria

Exclusion Criteria:

  1. Subject has a chronic illness related to Lyme borreliosis (LB), an active symptomatic LB (Lyme borreliosis) as suspected or diagnosed by a physician, or received treatment for LB (Lyme borreliosis) within the last 3 months prior to Visit 0;
  2. Subject received previous vaccination against Lyme borreliosis (LB).;
  3. Subject had a tick bite within 4 weeks prior to Visit 1;
  4. Subject has a medical history of or currently has a clinically relevant disease (cardiovascular, respiratory, neurologic, psychiatric conditions) which poses a risk for participation in the study, based on investigators judgement, such as individuals with poorly controlled or unstable disease, ongoing suspected or active inflammation, or poor compliance with pharmacologic treatment. Subjects with pharmacologically controlled conditions like osteoarthritis, depression, or asthma are eligible;
  5. Subject has a medical history of or currently has a neuroinflammatory or autoimmune disease, including Guillain Barré Syndrome;
  6. Subject has a known thrombocytopenia, bleeding disorder, or received anticoagulants in the 3 weeks prior to first vaccination or until Day 57 (Visit 3), contraindicating intramuscular vaccination as judged by the investigator;
  7. Subject has received an active or passive immunization within 28 days before first vaccination at Visit 1 and until Day 85; except for influenza (seasonal or pandemic) and pneumococcal vaccines which may be administered outside a 7-days interval before or after any trial vaccination;
  8. Subject has received any other non-registered medicinal product in another clinical trial within 28 days prior to VLA15 vaccination at Visit 1 (Day 1) and throughout the entire study period or has received a registered medicinal product in another clinical trial within 28 days prior to VLA15 vaccination at Visit 1 (Day 1) and up to Day 85;
  9. Subject has a known or suspected defect of the immune system that would prevent an immune response to the vaccine, such as subjects with congenital or acquired immunodeficiency, including infection with human immunodeficiency virus (HIV), status post organ transplantation or immuno-suppressive therapy within 30 days prior to Visit 1. Immuno-suppressive therapy is defined as administration of chronic (longer than 14 days) prednisone or equivalent 0.05 mg per kg/ per day. Topical and inhaled steroids are allowed;
  10. Subject has a history of anaphylaxis or severe allergic reactions or a known hypersensitivity or allergic reactions to one of the components of the vaccine;
  11. Subject had any malignancy in the past 5 years. If treatment for cancer was successfully completed more than 5 years ago and the malignancy is considered to be cured, the subject may be enrolled;
  12. Subject had acute febrile infections within 10 days prior to first vaccination;
  13. Subject is pregnant (positive serum pregnancy test at screening), has plans to become pregnant during the course of the study or is lactating at the time of enrollment. Women of childbearing potential that are unwilling or unable to employ an adequate birth control measure for the duration of the study.
  14. Subject has donated blood or blood-derived products (plasma) within 30 days or received blood or blood-derived products (plasma) within 90 days prior to first vaccination in this study or plans to donate or use blood or blood products during the course of the study;
  15. Subject has any condition that, in the opinion of the investigator, may compromise the subject's well-being, might interfere with evaluation of study endpoints, or would limit the subject's ability to complete the study;
  16. Subject is committed to an institution (by virtue of an order issued either by the judicial or the administrative authorities);
  17. Subject is in a dependent relationship with the sponsor, an investigator or other study team member, or the study center. Dependent relationships include close relatives and household members (i.e. children, partner/spouse, siblings, parents) as well as employees of the investigator or study center personnel.
05

Study design

Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
572 participants (actual)

Study arms

  • Active comparator
    VLA15 low dose

    VLA15 low dose with Alum.

    Biological: VLA15

  • Active comparator
    VLA15 medium dose

    VLA15 medium dose with Alum.

    Biological: VLA15

  • Active comparator
    VLA15 high dose

    VLA15 high dose with Alum.

    Biological: VLA15

  • Placebo comparator
    Placebo

    Biological: Placebo

Interventions

  • BiologicalVLA15

    a multivalent recombinant Outer surface protein A (OspA) based vaccine candidate

  • BiologicalPlacebo

    Placebo: PBS (Phosphate Buffered Saline)

06

What researchers measure

Primary outcomes

  1. GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype ST1 to ST6

    GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype ST1 to ST6, determined by ELISA at Day 85. GMTs are calculated based on the number of subjects with non-missing results.

    Time frame: at Day 85 / Month 3

Secondary outcomes

  1. GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)

    GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA. GMTs are calculated based on the number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  2. SCRs (Seroconversion Rate) for Each OspA (Outer Surface Protein A) Serotype Specific IgG (Immunoglobulin G) (ST1 to ST6),

    Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a certain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

    Time frame: up to Day 365 / Month 12

  3. GMFR (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)

    GMFR (Geometric Mean of the Fold Rise as compared to baseline) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA. Calculations are based on number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  4. GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

    GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA, stratified by age group - Group 18 - 49 years. GMTs are calculated based on the number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  5. GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

    GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), determined by ELISA, stratified by age group - Group 50 - 65 years. GMTs are calculated based on the number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  6. SCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

    SCRs (Seroconversion Rate) for Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a vertain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

    Time frame: up to Day 365 / Month 12

  7. SCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

    Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a vertain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

    Time frame: up to Day 365 / Month 12

  8. GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

    GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), stratified by age group - Group 18 - 49 years. Calculations are based on number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  9. GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

    GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), stratified by age group - Group 50 - 65 years. Calculations are based on number of subjects with non-missing results.

    Time frame: up to Day 365 / Month 12

  10. Percentage of Participants With SAEs (Serious Adverse Events)

    Frequency of SAEs (Serious Adverse Events) during the entire study; frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  11. Percentage of Participants With Related SAEs (Serious Adverse Events)

    Frequency of related SAEs (Serious Adverse Events) during the entire study; frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  12. Percentage of Participants With AESIs (Adverse Events of Special Interest)

    Frequency of AESIs (Adverse Events of Special Interest) during the entire study; frequency is being assessed in terms of percentage of participants. AESIs are cases of Lyme Diseases, Lyme associated Events and the onset of potentially autoimmune or neuro-inflammatory disorders.

    Time frame: up to Day 365 / Month 12

  13. Percentage of Participants With Related AESIs (Adverse Events of Special Interest)

    Frequency of related AESIs (Adverse Events of Special Interest) during the entire study; frequency is being assessed in terms of percentage of participants. AESIs are cases of Lyme Diseases, Lyme associated Events and the onset of potentially autoimmune or neuro-inflammatory disorders.

    Time frame: up to Day 365 / Month 12

  14. Percentage of Participants With Unsolicited AEs (Adverse Events)

    Frequency of unsolicited AEs (Adverse Events) during the entire study (incl. clinically relevant laboratory parameters); frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  15. Percentage of Participants With Related Unsolicited AEs (Adverse Events)

    Frequency of related unsolicited AEs (Adverse Events) during the entire study (incl. clinically relevant laboratory parameters); frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  16. Percentage of Participants With Solicited Local and Solicited Systemic AEs (Adverse Events)

    Frequency of solicited local and solicited systemic AEs (Adverse Events) within 7 days after each and after any vaccination; frequency is being assessed in terms of percentage of participants.

    Time frame: Day 1 (day of first vaccination) through Day 7; Day 29 (day of second vaccination) through Day 35; Day 57 (day of third vaccination) through Day 63

  17. Percentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 18-49

    Frequency of SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), solicited and unsolicited AEs (Adverse Events) during the entire study stratified by age group - Group 18-49; frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  18. Percentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 50-65 Years

    Frequency of SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) during the entire study stratified by age group - Group 50-65 years; frequency is being assessed in terms of percentage of participants.

    Time frame: up to Day 365 / Month 12

  19. Number of Participants With AESIs (Adverse Events of Special Interest) up to Study End

    Time frame: up to Day 365 / Month 12

07

Results

Posted Jun 30, 2021

Participant flow

Participant flow — Overall Study
MilestoneVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Started29214205124
Completed25196197115
Not completed41889
Withdrew: Withdrawal by subject0741
Withdrew: Moved from study area0211
Withdrew: Lost to follow-up3636
Withdrew: Other1301

Outcome measures

PrimaryGMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype ST1 to ST6

GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype ST1 to ST6, determined by ELISA at Day 85. GMTs are calculated based on the number of subjects with non-missing results.

Time frame:
at Day 85 / Month 3
Reported as:
Geometric mean · U/mL
GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype ST1 to ST6
U/mLVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 8574.3 (46.4 to 119.0)101.9 (87.1 to 119.4)115.8 (98.8 to 135.7)21.7 (20.0 to 23.6)
ST2 Day 85180.9 (124.8 to 262.3)279.3 (247.1 to 315.8)303.7 (266.5 to 346.1)21.1 (20.0 to 22.3)
ST3 Day 85267.4 (194.8 to 367.1)283.2 (248.2 to 323.1)308.6 (266.8 to 356.8)20.8 (19.8 to 21.8)
ST4 Day 85117.0 (76.6 to 178.7)170.9 (150.5 to 194.2)190.7 (165.9 to 219.2)21.8 (20.4 to 23.4)
ST5 Day 85118.3 (78.3 to 178.9)176.0 (154.2 to 201.0)199.6 (172.5 to 230.9)21.4 (20.2 to 22.6)
ST6 Day 85115.6 (76.5 to 174.7)183.6 (161.7 to 208.4)208.7 (181.8 to 239.6)21.8 (20.3 to 23.4)
SecondaryGMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)

GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA. GMTs are calculated based on the number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · U/mL
GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)
U/mLVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 120.8 (19.2 to 22.5)20.5 (19.8 to 21.3)20.2 (19.8 to 20.6)21.6 (19.9 to 23.5)
ST1 Day 2921.1 (18.9 to 23.5)21.8 (20.0 to 23.8)21.2 (20.1 to 22.4)21.7 (20.0 to 23.7)
ST1 Day 5732.7 (25.1 to 42.6)37.5 (32.4 to 43.3)41.2 (35.7 to 47.5)21.9 (20.1 to 23.8)
ST1 Day 18026.2 (19.9 to 34.5)32.8 (28.8 to 37.3)33.9 (30.0 to 38.3)21.0 (19.8 to 22.3)
ST1 Day 23622.2 (18.8 to 26.1)25.7 (22.8 to 28.8)26.2 (23.1 to 29.7)21.5 (19.6 to 23.6)
ST1 Day 36520.9 (19.1 to 22.9)23.4 (21.4 to 25.6)23.0 (21.3 to 24.9)21.4 (19.9 to 22.9)
ST2 Day 121.3 (18.7 to 24.2)20.0 (20.0 to 20.0)20.1 (19.9 to 20.2)20.7 (19.7 to 21.8)
ST2 Day 2921.1 (18.9 to 23.7)21.1 (20.0 to 22.2)21.4 (20.5 to 22.4)21.0 (19.9 to 22.1)
ST2 Day 5769.0 (47.7 to 99.8)89.2 (75.9 to 104.9)107.8 (92.7 to 125.2)21.3 (20.0 to 22.6)
ST2 Day 18041.2 (29.3 to 57.9)62.5 (54.5 to 71.7)67.1 (58.3 to 77.1)20.6 (19.7 to 21.5)
ST2 Day 23626.6 (21.2 to 33.4)36.8 (32.1 to 42.2)35.7 (30.9 to 41.2)20.5 (19.5 to 21.5)
ST2 Day 36521.8 (19.2 to 24.7)24.6 (22.8 to 26.6)24.8 (23.1 to 26.6)20.6 (19.7 to 21.5)
ST3 Day 121.9 (19.1 to 25.1)20.4 (20.0 to 20.8)20.1 (19.9 to 20.4)20.4 (19.6 to 21.2)
ST3 Day 2923.7 (20.0 to 28.0)21.7 (20.2 to 23.2)21.2 (20.3 to 22.1)20.8 (19.8 to 21.9)
ST3 Day 57110.2 (71.1 to 171.0)123.8 (104.4 to 146.9)145.8 (122.8 to 173.0)21.2 (20.0 to 22.6)
ST3 Day 18053.1 (35.6 to 79.1)63.1 (55.2 to 72.2)68.7 (59.5 to 79.2)20.5 (19.8 to 21.3)
ST3 Day 23635.3 (25.7 to 48.6)35.8 (31.2 to 41.1)39.0 (33.3 to 45.8)20.6 (19.7 to 21.7)
ST3 Day 36525.2 (19.9 to 31.8)25.6 (23.5 to 27.9)27.0 (24.5 to 29.8)20.5 (19.8 to 21.3)
ST4 Day 121.4 (18.7 to 24.4)21.0 (20.3 to 21.7)20.2 (19.9 to 20.6)21.7 (20.3 to 23.2)
ST4 Day 2922.1 (19.1 to 25.6)21.9 (20.4 to 23.6)21.4 (20.4 to 22.4)22.0 (20.4 to 23.6)
ST4 Day 5745.9 (32.8 to 64.2)57.4 (49.5 to 66.6)64.7 (55.5 to 75.5)22.0 (20.4 to 23.8)
ST4 Day 18032.8 (24.1 to 44.6)48.1 (42.5 to 54.5)49.3 (43.1 to 56.3)21.5 (20.2 to 22.9)
ST4 Day 23625.5 (20.6 to 31.5)32.8 (29.0 to 37.2)31.9 (27.7 to 36.6)21.7 (20.0 to 23.5)
ST4 Day 36521.8 (19.2 to 24.7)26.5 (24.2 to 28.9)25.5 (23.2 to 27.9)21.7 (20.3 to 23.2)
ST5 Day 120.6 (19.4 to 21.8)20.7 (20.1 to 21.3)20.2 (19.8 to 20.5)21.4 (20.2 to 22.7)
ST5 Day 2920.7 (19.2 to 22.4)21.2 (20.0 to 22.5)21.0 (20.2 to 21.9)21.4 (20.1 to 22.7)
ST5 Day 5742.7 (29.8 to 61.3)57.9 (44.9 to 67.2)72.2 (61.6 to 84.7)21.5 (20.2 to 22.9)
ST5 Day 18026.7 (20.7 to 34.3)44.0 (38.8 to 49.8)50.0 (43.5 to 57.4)21.1 (20.0 to 22.3)
ST5 Day 23623.0 (19.6 to 27.0)31.0 (27.5 to 35.0)32.4 (28.0 to 37.4)21.5 (20.0 to 23.1)
ST5 Day 36521.7 (19.3 to 24.3)24.0 (22.3 to 25.8)24.9 (22.7 to 27.2)21.1 (20.0 to 22.2)
ST6 Day 121.1 (18.9 to 23.5)21.3 (20.4 to 22.2)20.8 (20.1 to 21.6)21.6 (20.2 to 23.2)
ST6 Day 2921.1 (18.9 to 23.6)22.7 (21.2 to 24.3)22.0 (20.9 to 23.2)22.0 (20.4 to 23.7)
ST6 Day 5742.3 (29.8 to 60.1)55.5 (48.1 to 64.1)65.3 (55.6 to 76.7)22.1 (20.4 to 23.9)
ST6 Day 18030.1 (22.6 to 40.2)48.4 (42.8 to 54.8)51.4 (44.7 to 59.0)21.4 (20.1 to 22.8)
ST6 Day 23625.6 (20.7 to 31.8)33.4 (29.5 to 37.8)33.2 (28.6 to 38.6)22.1 (20.2 to 24.3)
ST6 Day 36522.1 (19.2 to 25.5)25.7 (23.8 to 27.9)26.0 (23.6 to 28.7)21.8 (20.3 to 23.3)
SecondarySCRs (Seroconversion Rate) for Each OspA (Outer Surface Protein A) Serotype Specific IgG (Immunoglobulin G) (ST1 to ST6),

Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a certain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of subjects
SCRs (Seroconversion Rate) for Each OspA (Outer Surface Protein A) Serotype Specific IgG (Immunoglobulin G) (ST1 to ST6),
percentage of subjectsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 290.0 (0.0 to 11.7)3.7 (1.8 to 7.4)3.1 (1.4 to 6.6)0.8 (0.1 to 4.6)
ST1 Day 5739.3 (23.6 to 57.6)37.2 (30.6 to 44.2)40.7 (34.1 to 47.8)1.7 (0.5 to 5.8)
ST1 Day 18011.5 (4.0 to 29.0)32.8 (26.4 to 39.9)35.4 (29.0 to 42.5)0.9 (0.2 to 4.8)
ST1 Day 2367.7 (2.1 to 24.1)17.2 (11.5 to 24.9)18.5 (12.5 to 26.4)2.6 (0.7 to 9.1)
ST1 Day 3654.0 (0.7 to 19.5)10.9 (7.2 to 16.3)8.9 (5.6 to 13.8)1.8 (0.5 to 6.2)
ST2 Day 290.0 (0.0 to 11.7)2.6 (1.1 to 6.0)5.7 (3.2 to 9.9)0.8 (0.1 to 4.6)
ST2 Day 5767.9 (49.3 to 82.1)72.3 (65.5 to 78.1)79.9 (73.7 to 84.9)1.7 (0.5 to 5.8)
ST2 Day 18042.3 (25.5 to 61.1)66.1 (59.0 to 72.6)66.7 (59.7 to 73.0)0.9 (0.2 to 4.8)
ST2 Day 23619.2 (8.5 to 37.9)42.6 (34.2 to 51.5)38.7 (30.4 to 47.6)0.0 (0.0 to 4.8)
ST2 Day 3658.0 (2.2 to 25.0)15.3 (10.8 to 21.2)17.8 (13.0 to 23.8)0.9 (0.2 to 4.8)
ST3 Day 296.9 (1.9 to 22.0)4.2 (2.1 to 8.0)3.6 (1.8 to 7.3)1.7 (0.5 to 5.9)
ST3 Day 5775.0 (56.6 to 87.3)80.1 (73.9 to 85.1)84.0 (78.2 to 88.5)2.5 (0.8 to 7.0)
ST3 Day 18050.0 (32.1 to 67.9)68.9 (61.8 to 75.1)69.3 (62.4 to 75.4)1.8 (0.5 to 6.2)
ST3 Day 23634.6 (19.4 to 53.8)39.3 (31.1 to 48.2)42.0 (33.5 to 51.0)2.6 (0.7 to 9.1)
ST3 Day 36512.0 (4.2 to 30.0)17.5 (12.7 to 23.6)19.9 (14.9 to 26.1)1.8 (0.5 to 6.2)
ST4 Day 293.4 (0.6 to 17.2)2.6 (1.1 to 6.0)3.6 (1.8 to 7.3)0.8 (0.1 to 4.6)
ST4 Day 5750.0 (32.6 to 67.4)58.6 (51.6 to 65.4)67.0 (60.1 to 73.2)0.8 (0.1 to 4.5)
ST4 Day 18030.8 (16.5 to 50.0)57.4 (50.1 to 64.3)58.2 (51.1 to 65.0)0.9 (0.2 to 4.8)
ST4 Day 23615.4 (6.2 to 33.5)36.1 (28.1 to 44.9)31.9 (24.2 to 40.8)1.3 (0.2 to 7.1)
ST4 Day 3658.0 (2.2 to 25.0)19.7 (14.6 to 26.0)16.8 (12.1 to 22.7)2.7 (0.9 to 7.5)
ST5 Day 290.0 (0.0 to 11.7)1.6 (0.5 to 4.5)2.6 (1.1 to 5.9)0.0 (0.0 to 3.1)
ST5 Day 5742.9 (26.5 to 60.9)58.1 (51.0 to 64.9)67.5 (60.7 to 73.7)0.0 (0.0 to 3.1)
ST5 Day 18019.2 (8.5 to 37.9)49.7 (42.6 to 56.9)55.0 (47.9 to 61.9)0.9 (0.2 to 4.8)
ST5 Day 23611.5 (4.0 to 29.0)32.0 (24.4 to 40.7)31.9 (24.2 to 40.8)1.3 (0.2 to 7.1)
ST5 Day 3658.0 (2.2 to 25.0)13.1 (9.0 to 18.8)13.1 (9.0 to 18.6)0.9 (0.2 to 4.8)
ST6 Day 290.0 (0.0 to 11.7)6.3 (3.6 to 10.7)4.6 (2.5 to 8.6)1.7 (0.5 to 5.9)
ST6 Day 5742.9 (26.5 to 60.9)54.5 (47.4 to 61.4)60.3 (53.3 to 66.9)1.7 (0.5 to 5.8)
ST6 Day 18023.1 (11.0 to 42.1)54.1 (46.9 to 61.2)53.4 (46.3 to 60.4)2.6 (0.9 to 7.5)
ST6 Day 23615.4 (6.2 to 33.5)35.2 (27.3 to 44.1)31.1 (23.5 to 39.9)3.9 (1.4 to 11.0)
ST6 Day 3658.0 (2.2 to 25.0)16.9 (12.2 to 23.0)13.6 (9.5 to 19.2)3.5 (1.4 to 8.7)
SecondaryGMFR (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)

GMFR (Geometric Mean of the Fold Rise as compared to baseline) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA. Calculations are based on number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · Geometric Mean of the Fold Rise
GMFR (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6)
Geometric Mean of the Fold RiseVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 291.0 (1.0 to 1.0)1.1 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST1 Day 571.6 (1.2 to 2.1)1.8 (1.6 to 2.1)2.0 (1.8 to 2.4)1.0 (1.0 to 1.0)
ST1 Day 1801.3 (1.0 to 1.6)1.6 (1.4 to 1.8)1.7 (1.5 to 1.9)1.0 (1.0 to 1.0)
ST1 Day 2361.1 (0.9 to 1.3)1.3 (1.1 to 1.4)1.3 (1.2 to 1.5)1.0 (1.0 to 1.1)
ST1 Day 3651.0 (0.9 to 1.1)1.1 (1.1 to 1.2)1.1 (1.1 to 1.2)1.0 (1.0 to 1.1)
ST2 Day 291.0 (1.0 to 1.0)1.1 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST2 Day 573.2 (2.2 to 4.7)4.5 (3.8 to 5.2)5.4 (4.6 to 6.2)1.0 (1.0 to 1.1)
ST2 Day 1801.9 (1.4 to 2.7)3.1 (2.7 to 3.6)3.3 (2.9 to 3.8)1.0 (1.0 to 1.0)
ST2 Day 2361.2 (1.0 to 1.6)1.8 (1.6 to 2.1)1.8 (1.5 to 2.1)1.0 (1.0 to 1.0)
ST2 Day 3651.1 (1.0 to 1.2)1.2 (1.1 to 1.3)1.2 (1.1 to 1.3)1.0 (1.0 to 1.0)
ST3 Day 291.1 (1.0 to 1.2)1.1 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.1)
ST3 Day 575.0 (3.2 to 7.8)6.1 (5.1 to 7.2)7.2 (6.1 to 8.6)1.0 (1.0 to 1.1)
ST3 Day 1802.4 (1.6 to 3.6)3.1 (2.7 to 3.5)3.4 (3.0 to 3.9)1.0 (1.0 to 1.1)
ST3 Day 2361.6 (1.2 to 2.2)1.8 (1.5 to 2.0)1.9 (1.6 to 2.3)1.0 (1.0 to 1.1)
ST3 Day 3651.2 (1.0 to 1.4)1.3 (1.2 to 1.4)1.3 (1.2 to 1.5)1.0 (1.0 to 1.1)
ST4 Day 291.0 (1.0 to 1.1)1.0 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST4 Day 572.1 (1.5 to 3.0)2.7 (2.4 to 3.2)3.2 (2.7 to 3.7)1.0 (1.0 to 1.0)
ST4 Day 1801.5 (1.1 to 2.1)2.3 (2.0 to 2.6)2.4 (2.1 to 2.8)1.0 (1.0 to 1.0)
ST4 Day 2361.2 (0.9 to 1.5)1.6 (1.4 to 1.8)1.6 (1.4 to 1.8)1.0 (1.0 to 1.1)
ST4 Day 3651.1 (1.0 to 1.2)1.3 (1.2 to 1.4)1.3 (1.1 to 1.4)1.0 (1.0 to 1.1)
ST5 Day 291.0 (1.0 to 1.0)1.0 (1.0 to 1.1)1.0 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST5 Day 572.1 (1.5 to 3.0)2.8 (2.4 to 3.2)3.6 (3.1 to 4.2)1.0 (1.0 to 1.0)
ST5 Day 1801.3 (1.0 to 1.7)2.1 (1.9 to 2.4)2.5 (2.2 to 2.8)1.0 (1.0 to 1.0)
ST5 Day 2361.1 (0.9 to 1.3)1.5 (1.4 to 1.7)1.6 (1.4 to 1.8)1.0 (1.0 to 1.0)
ST5 Day 3651.1 (1.0 to 1.2)1.2 (1.1 to 1.2)1.2 (1.1 to 1.3)1.0 (1.0 to 1.0)
ST6 Day 291.0 (1.0 to 1.0)1.1 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST6 Day 572.0 (1.4 to 2.8)2.6 (2.3 to 3.0)3.1 (2.7 to 3.7)1.0 (1.0 to 1.0)
ST6 Day 1801.4 (1.1 to 1.9)2.3 (2.0 to 2.6)2.5 (2.1 to 2.8)1.0 (1.0 to 1.1)
ST6 Day 2361.2 (1.0 to 1.5)1.6 (1.4 to 1.8)1.6 (1.4 to 1.9)1.0 (1.0 to 1.1)
ST6 Day 3651.1 (1.0 to 1.3)1.2 (1.1 to 1.3)1.2 (1.1 to 1.4)1.0 (1.0 to 1.1)
SecondaryGMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) against each OspA (Outer Surface Protein A) serotype (ST1 to ST6), determined by ELISA, stratified by age group - Group 18 - 49 years. GMTs are calculated based on the number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · U/mL
GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years
U/mLVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 120.8 (19.2 to 22.5)20.3 (19.7 to 21.0)20.3 (19.7 to 20.8)22.0 (19.6 to 24.6)
ST1 Day 2921.1 (18.9 to 23.5)20.9 (19.7 to 22.1)21.4 (19.9 to 23.0)22.0 (19.6 to 24.6)
ST1 Day 5732.7 (25.1 to 42.6)34.8 (30.0 to 40.3)43.6 (36.5 to 52.0)22.4 (19.9 to 25.2)
ST1 Day 8574.3 (46.4 to 119.0)105.2 (88.8 to 124.5)129.6 (107.6 to 156.2)21.9 (19.6 to 24.5)
ST1 Day 18026.2 (19.9 to 34.5)31.7 (27.5 to 36.4)34.7 (29.7 to 40.5)21.0 (19.5 to 22.7)
ST1 Day 23622.2 (18.8 to 26.1)26.1 (22.5 to 30.3)26.4 (22.4 to 31.2)21.7 (19.3 to 24.4)
ST1 Day 36520.9 (19.1 to 22.9)23.0 (21.1 to 25.1)23.8 (21.4 to 26.5)21.7 (19.7 to 23.9)
ST2 Day 121.3 (18.7 to 24.2)20.0 (20.0 to 20.0)20.1 (19.9 to 20.3)21.0 (19.6 to 22.5)
ST2 Day 2921.1 (18.9 to 23.7)20.7 (19.9 to 21.5)21.4 (20.5 to 22.3)21.0 (19.6 to 22.4)
ST2 Day 5769.0 (47.7 to 99.8)89.5 (74.2 to 107.9)121.4 (102.4 to 143.9)21.4 (19.8 to 23.2)
ST2 Day 85180.9 (124.8 to 262.3)296.5 (258.6 to 339.9)322.1 (277.1 to 374.4)21.2 (19.8 to 22.7)
ST2 Day 18041.2 (29.3 to 57.9)64.5 (54.7 to 76.0)71.8 (60.8 to 84.7)20.5 (19.5 to 21.6)
ST2 Day 23626.6 (21.2 to 33.4)39.6 (33.5 to 46.8)37.0 (31.2 to 43.9)20.6 (19.4 to 22.0)
ST2 Day 36521.8 (19.2 to 24.7)24.5 (22.4 to 26.8)25.1 (23.0 to 27.4)20.5 (19.5 to 21.6)
ST3 Day 121.9 (19.1 to 25.1)20.3 (19.9 to 20.7)20.2 (19.8 to 20.5)20.6 (19.5 to 21.7)
ST3 Day 2923.7 (20.0 to 28.0)21.0 (20.1 to 21.9)21.7 (20.5 to 23.0)20.7 (19.6 to 21.9)
ST3 Day 57110.2 (71.1 to 171.0)122.6 (101.3 to 148.3)159.4 (130.1 to 195.2)21.3 (19.7 to 22.9)
ST3 Day 85267.4 (194.8 to 367.1)295.1 (255.6 to 340.8)334.2 (282.1 to 395.9)20.7 (19.6 to 21.8)
ST3 Day 18053.1 (35.6 to 79.1)60.7 (51.7 to 71.2)73.0 (61.3 to 86.9)20.0 (20.0 to 20.0)
ST3 Day 23635.3 (25.7 to 48.6)35.8 (30.4 to 42.2)39.9 (33.0 to 48.3)20.2 (19.8 to 20.7)
ST3 Day 36525.2 (19.9 to 31.8)25.4 (23.2 to 27.8)28.0 (24.7 to 31.8)20.2 (19.8 to 20.7)
ST4 Day 121.4 (18.7 to 24.4)20.8 (20.0 to 21.6)20.3 (19.9 to 20.8)22.0 (20.2 to 24.0)
ST4 Day 2922.1 (19.1 to 25.6)21.5 (20.4 to 22.8)21.5 (20.3 to 22.8)22.3 (20.4 to 24.4)
ST4 Day 5745.9 (32.8 to 64.2)56.9 (48.3 to 67.1)71.4 (59.1 to 86.3)22.4 (20.4 to 24.6)
ST4 Day 85117.0 (76.6 to 178.7)177.1 (154.5 to 203.1)206.8 (175.0 to 244.3)22.1 (20.3 to 24.1)
ST4 Day 18032.8 (24.1 to 44.6)48.2 (41.8 to 55.6)53.2 (44.9 to 63.0)21.7 (20.0 to 23.5)
ST4 Day 23625.5 (20.6 to 31.5)34.9 (29.9 to 40.8)33.6 (28.1 to 40.1)21.2 (19.5 to 23.2)
ST4 Day 36521.8 (19.2 to 24.7)26.7 (24.2 to 29.5)26.7 (23.5 to 30.3)21.4 (19.9 to 23.0)
ST5 Day 120.6 (19.4 to 21.8)20.4 (19.9 to 20.9)20.2 (19.8 to 20.8)21.5 (20.0 to 23.1)
ST5 Day 2920.7 (19.2 to 22.4)20.6 (19.9 to 21.3)21.1 (20.1 to 22.1)21.4 (20.0 to 22.9)
ST5 Day 5742.7 (29.8 to 61.3)56.6 (47.8 to 67.0)80.7 (66.3 to 98.1)21.6 (20.0 to 23.3)
ST5 Day 85118.3 (78.3 to 178.9)180.7 (156.8 to 208.2)218.3 (183.6 to 259.7)21.4 (20.0 to 22.9)
ST5 Day 18026.7 (20.7 to 34.3)42.5 (36.7 to 49.1)54.6 (45.9 to 64.8)20.8 (19.7 to 21.9)
ST5 Day 23623.0 (19.6 to 27.0)31.9 (27.5 to 37.1)33.4 (27.7 to 40.2)21.0 (19.6 to 22.6)
ST5 Day 36521.7 (19.3 to 24.3)24.0 (22.2 to 26.0)26.0 (23.0 to 29.5)20.8 (19.7 to 21.9)
ST6 Day 121.1 (18.9 to 23.5)20.8 (20.0 to 21.5)21.2 (20.1 to 22.4)21.7 (20.0 to 23.6)
ST6 Day 2921.1 (18.9 to 23.6)22.3 (21.0 to 23.7)22.2 (20.8 to 23.7)22.1 (20.3 to 24.0)
ST6 Day 5742.3 (29.8 to 60.1)54.5 (46.2 to 64.3)72.3 (59.2 to 88.3)22.3 (20.3 to 24.4)
ST6 Day 85115.6 (76.5 to 174.7)185.8 (162.2 to 213.0)225.6 (191.9 to 265.3)21.8 (20.1 to 23.7)
ST6 Day 18030.1 (22.6 to 40.2)46.7 (40.4 to 53.9)54.2 (45.5 to 64.4)20.6 (19.7 to 21.4)
ST6 Day 23625.6 (20.7 to 31.8)34.6 (29.8 to 40.2)34.6 (28.7 to 41.9)21.4 (19.7 to 23.2)
ST6 Day 36522.1 (19.2 to 25.5)25.5 (23.3 to 27.9)27.7 (24.3 to 31.6)21.4 (20.1 to 22.7)
SecondaryGMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), determined by ELISA, stratified by age group - Group 50 - 65 years. GMTs are calculated based on the number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · U/mL
GMTs (Geometric Mean Titers) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years
U/mLVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 1—21.0 (19.0 to 23.3)20.0 (20.0 to 20.0)20.6 (19.4 to 22.0)
ST1 Day 29—24.2 (18.7 to 31.4)20.9 (19.5 to 22.5)21.0 (19.6 to 22.6)
ST1 Day 57—44.5 (31.7 to 62.3)36.2 (28.6 to 45.8)20.5 (19.5 to 21.6)
ST1 Day 85—95.3 (67.2 to 135.1)89.2 (66.0 to 120.4)21.2 (19.5 to 23.1)
ST1 Day 180—35.4 (26.8 to 46.9)32.1 (26.4 to 39.0)21.0 (19.6 to 22.5)
ST1 Day 236—24.5 (20.4 to 29.4)25.6 (21.4 to 30.5)20.9 (19.1 to 22.9)
ST1 Day 365—24.3 (19.6 to 30.1)21.4 (19.6 to 23.2)20.5 (19.4 to 21.7)
ST2 Day 1—20.0 (20.0 to 20.0)20.0 (20.0 to 20.0)20.0 (20.0 to 20.0)
ST2 Day 29—22.0 (18.9 to 25.7)21.6 (19.4 to 24.0)20.9 (19.1 to 22.8)
ST2 Day 57—88.7 (64.1 to 122.5)81.5 (60.4 to 110.2)20.9 (19.1 to 22.8)
ST2 Day 85—245.5 (190.3 to 316.6)265.0 (204.2 to 344.0)20.8 (19.2 to 22.4)
ST2 Day 180—58.5 (45.4 to 75.3)57.4 (44.1 to 74.5)20.8 (19.2 to 22.4)
ST2 Day 236—30.5 (24.1 to 38.7)32.7 (24.8 to 43.1)20.0 (20.0 to 20.0)
ST2 Day 365—24.9 (21.3 to 29.2)24.1 (21.3 to 27.3)20.9 (19.1 to 22.7)
ST3 Day 1—20.7 (19.7 to 21.7)20.0 (20.0 to 20.0)20.0 (20.0 to 20.0)
ST3 Day 29—23.3 (18.9 to 28.7)20.0 (20.0 to 20.0)21.2 (18.8 to 23.8)
ST3 Day 57—126.7 (88.0 to 182.4)118.3 (85.7 to 163.1)21.1 (18.9 to 23.6)
ST3 Day 85—258.9 (194.9 to 343.8)256.5 (193.5 to 340.0)21.1 (19.0 to 23.4)
ST3 Day 180—68.8 (53.5 to 88.4)59.7 (46.4 to 76.7)21.9 (19.1 to 25.0)
ST3 Day 236—35.7 (27.3 to 46.8)36.9 (27.2 to 50.1)22.0 (18.0 to 26.9)
ST3 Day 365—26.0 (21.5 to 31.5)24.8 (21.6 to 28.4)21.3 (18.7 to 24.2)
ST4 Day 1—21.3 (19.8 to 23.0)20.0 (20.0 to 20.0)20.9 (19.1 to 22.9)
ST4 Day 29—22.9 (18.7 to 28.0)21.0 (19.4 to 22.8)21.2 (18.8 to 23.8)
ST4 Day 57—58.6 (42.6 to 80.6)51.4 (39.8 to 66.4)21.2 (18.8 to 23.9)
ST4 Day 85—158.2 (119.5 to 209.4)158.1 (122.5 to 203.9)21.1 (18.9 to 23.4)
ST4 Day 180—48.0 (37.5 to 61.5)41.3 (33.6 to 50.9)21.1 (18.9 to 23.6)
ST4 Day 236—28.0 (23.1 to 33.8)28.0 (22.7 to 34.7)23.1 (18.7 to 28.5)
ST4 Day 365—26.0 (21.7 to 31.1)22.9 (20.9 to 25.1)22.5 (19.4 to 26.1)
ST5 Day 1—21.4 (19.8 to 23.0)20.0 (20.0 to 20.0)21.0 (19.0 to 23.4)
ST5 Day 29—22.7 (19.0 to 27.1)20.8 (19.2 to 22.6)21.3 (18.7 to 24.3)
ST5 Day 57—61.0 (44.9 to 82.9)55.7 (42.5 to 72.8)21.3 (18.7 to 24.2)
ST5 Day 85—166.4 (124.1 to 223.0)162.1 (124.0 to 211.9)21.2 (18.8 to 23.9)
ST5 Day 180—47.4 (37.2 to 60.5)40.8 (32.6 to 51.1)21.9 (19.1 to 25.2)
ST5 Day 236—28.8 (23.4 to 35.6)30.2 (24.1 to 37.7)23.1 (18.6 to 28.7)
ST5 Day 365—23.9 (20.5 to 27.8)22.4 (20.2 to 24.7)21.9 (19.1 to 25.2)
ST6 Day 1—22.6 (20.3 to 25.1)20.0 (20.0 to 20.0)21.4 (18.7 to 24.4)
ST6 Day 29—23.6 (19.9 to 28.1)21.6 (19.6 to 23.9)21.7 (18.3 to 25.8)
ST6 Day 57—58.0 (43.2 to 77.7)51.4 (39.3 to 67.1)21.7 (18.4 to 25.6)
ST6 Day 85—178.7 (136.2 to 236.3)174.3 (133.9 to 226.9)21.6 (18.5 to 25.3)
ST6 Day 180—52.3 (41.1 to 66.5)45.5 (36.1 to 57.3)23.6 (19.2 to 28.8)
ST6 Day 236—30.3 (24.1 to 38.1)30.1 (23.6 to 38.3)24.6 (18.0 to 33.6)
ST6 Day 365—26.2 (22.2 to 30.9)22.5 (20.2 to 25.0)22.8 (18.7 to 27.8)
SecondarySCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

SCRs (Seroconversion Rate) for Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a vertain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of subjects
SCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years
percentage of subjectsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 290.0 (0.0 to 11.7)2.3 (0.8 to 6.4)2.9 (1.1 to 7.3)0.0 (0.0 to 4.2)
ST1 Day 5739.3 (23.6 to 57.6)36.1 (28.4 to 44.5)43.4 (35.3 to 51.8)1.1 (0.2 to 6.2)
ST1 Day 8565.4 (46.2 to 80.6)85.9 (78.9 to 90.9)85.6 (78.6 to 90.6)0.0 (0.0 to 4.3)
ST1 Day 18011.5 (4.0 to 29.0)31.2 (23.7 to 39.8)36.4 (28.7 to 44.8)0.0 (0.0 to 4.5)
ST1 Day 2367.7 (2.1 to 24.1)18.2 (11.5 to 27.5)17.9 (11.1 to 27.4)1.7 (0.3 to 9.1)
ST1 Day 3654.0 (0.7 to 19.5)11.3 (6.8 to 18.1)10.5 (6.4 to 16.9)1.2 (0.2 to 6.6)
ST2 Day 290.0 (0.0 to 11.7)2.3 (0.8 to 6.4)6.6 (3.5 to 12.1)0.0 (0.0 to 4.2)
ST2 Day 5767.9 (49.3 to 82.1)72.9 (64.8 to 79.8)85.3 (78.4 to 90.3)1.1 (0.2 to 6.2)
ST2 Day 8588.5 (71.0 to 96.0)100 (97.1 to 100)96.2 (91.4 to 98.4)1.2 (0.2 to 6.4)
ST2 Day 18042.3 (25.5 to 61.1)68.0 (59.4 to 75.5)69.7 (61.4 to 76.9)0.0 (0.0 to 4.5)
ST2 Day 23619.2 (8.5 to 37.9)47.7 (37.6 to 58.0)41.7 (31.7 to 52.3)0.0 (0.0 to 6.2)
ST2 Day 3658.0 (2.2 to 25.0)15.3 (10.0 to 22.7)18.8 (13.1 to 26.3)0.0 (0.0 to 4.5)
ST3 Day 296.9 (1.9 to 22.0)3.0 (1.2 to 7.5)5.1 (2.5 to 10.2)1.1 (0.2 to 6.2)
ST3 Day 5775.0 (56.6 to 87.3)81.2 (73.7 to 86.9)85.3 (78.4 to 90.3)2.3 (0.6 to 7.9)
ST3 Day 8596.2 (81.1 to 99.3)98.4 (94.5 to 99.6)97.0 (92.5 to 98.8)1.2 (0.2 to 6.4)
ST3 Day 18050.0 (32.1 to 67.9)66.4 (57.7 to 74.1)70.5 (62.2 to 77.6)0.0 (0.0 to 4.5)
ST3 Day 23634.6 (19.4 to 53.8)39.8 (30.2 to 50.2)44.0 (33.9 to 54.7)1.7 (0.3 to 9.1)
ST3 Day 36512.0 (4.2 to 30.0)19.4 (13.4 to 27.2)21.8 (15.6 to 29.6)1.2 (0.2 to 6.6)
ST4 Day 293.4 (0.6 to 17.2)2.3 (0.8 to 6.5)3.7 (1.6 to 8.3)1.1 (0.2 to 6.2)
ST4 Day 5750.0 (32.6 to 67.4)60.2 (51.7 to 68.1)71.3 (63.2 to 78.3)1.1 (0.2 to 6.2)
ST4 Day 8580.8 (62.1 to 91.5)96.1 (91.2 to 98.3)94.7 (89.5 to 97.4)1.2 (0.2 to 6.4)
ST4 Day 18030.8 (16.5 to 50.0)58.4 (49.6 to 66.7)60.6 (52.1 to 68.5)1.2 (0.2 to 6.6)
ST4 Day 23615.4 (6.2 to 33.5)38.6 (29.1 to 49.1)34.5 (25.2 to 45.2)0.0 (0.0 to 6.2)
ST4 Day 3658.0 (2.2 to 25.0)21.0 (14.7 to 29.0)18.0 (12.4 to 25.4)1.2 (0.2 to 6.6)
ST5 Day 290.0 (0.0 to 11.7)0.8 (0.1 to 4.1)2.9 (1.1 to 7.3)0.0 (0.0 to 4.2)
ST5 Day 5742.9 (26.5 to 60.9)59.4 (50.9 to 67.4)72.8 (64.8 to 79.6)0.0 (0.0 to 4.2)
ST5 Day 8580.8 (62.1 to 91.5)94.5 (89.1 to 97.3)91.7 (85.7 to 95.3)0.0 (0.0 to 4.3)
ST5 Day 18019.2 (8.5 to 37.9)48.8 (40.2 to 57.5)59.1 (50.6 to 67.1)0.0 (0.0 to 4.5)
ST5 Day 23611.5 (4.0 to 29.0)33.0 (24.0 to 43.3)32.1 (23.1 to 42.7)0.0 (0.0 to 6.2)
ST5 Day 3658.0 (2.2 to 25.0)15.3 (10.0 to 22.7)15.0 (10.0 to 22.1)0.0 (0.0 to 4.5)
ST6 Day 290.0 (0.0 to 11.7)6.8 (3.6 to 12.4)4.4 (2.0 to 9.3)2.3 (0.6 to 7.9)
ST6 Day 5742.9 (26.5 to 60.9)55.6 (47.2 to 63.8)64.0 (55.6 to 71.6)2.3 (0.6 to 7.9)
ST6 Day 8580.8 (62.1 to 91.5)95.3 (90.2 to 97.8)92.4 (86.6 to 95.8)1.2 (0.2 to 6.4)
ST6 Day 18023.1 (11.0 to 42.1)54.4 (45.7 to 62.9)53.8 (45.3 to 62.1)1.2 (0.2 to 6.6)
ST6 Day 23615.4 (6.2 to 33.5)38.6 (29.1 to 49.1)32.1 (23.1 to 42.7)3.4 (1.0 to 11.7)
ST6 Day 3658.0 (2.2 to 25.0)17.7 (12.0 to 25.4)15.8 (10.6 to 22.9)3.7 (1.3 to 10.2)
SecondarySCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

Seroconversion for ELISA is defined as: * for subjects that are seronegative at Visit 1 (baseline): a change from seronegative at Visit 1 to seropositive (i.e. antibody titer of ≥40 U/mL) at a vertain time point. * for subjects that are seropositive at Visit 1 (baseline): a ≥ 4-fold rise in IgG antibody titer from Visit 1. Percentages are based on the number of subjects with non-missing observations.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of subjects
SCRs (Seroconversion Rate) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years
percentage of subjectsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 29—6.9 (2.7 to 16.4)3.4 (1.0 to 11.7)3.1 (0.6 to 15.7)
ST1 Day 57—39.7 (28.1 to 52.5)34.5 (23.6 to 47.3)3.0 (0.5 to 15.3)
ST1 Day 85—71.2 (58.6 to 81.2)71.9 (59.2 to 81.9)3.0 (0.5 to 15.3)
ST1 Day 180—36.2 (25.1 to 49.1)33.3 (22.5 to 46.3)3.1 (0.6 to 15.7)
ST1 Day 236—14.7 (6.4 to 30.1)20.0 (10.0 to 35.9)5.6 (1.0 to 25.8)
ST1 Day 365—10.2 (4.7 to 20.5)5.2 (1.8 to 14.1)3.2 (0.6 to 16.2)
ST2 Day 29—3.4 (1.0 to 11.7)3.4 (1.0 to 11.7)3.1 (0.6 to 15.7)
ST2 Day 57—70.7 (58.0 to 80.8)67.2 (54.4 to 77.9)3.0 (0.5 to 15.3)
ST2 Day 85—94.9 (86.1 to 98.3)93.0 (83.3 to 97.2)3.0 (0.5 to 15.3)
ST2 Day 180—62.1 (49.2 to 73.4)59.6 (46.7 to 71.4)3.1 (0.6 to 15.7)
ST2 Day 236—29.4 (16.8 to 46.2)31.4 (18.6 to 48.0)0.0 (0.0 to 17.6)
ST2 Day 365—15.3 (8.2 to 26.5)15.5 (8.4 to 26.9)3.2 (0.6 to 16.2)
ST3 Day 29—6.9 (2.7 to 16.4)0.0 (0.0 to 6.2)3.1 (0.6 to 15.7)
ST3 Day 57—77.6 (65.3 to 86.4)81.0 (69.1 to 89.1)3.0 (0.5 to 15.3)
ST3 Day 85—94.9 (86.1 to 98.3)93.0 (83.3 to 97.2)3.0 (0.5 to 15.3)
ST3 Day 180—74.1 (61.6 to 83.7)66.7 (53.7 to 77.5)6.3 (1.7 to 20.1)
ST3 Day 236—38.2 (23.9 to 55.0)37.1 (23.2 to 53.7)5.6 (1.0 to 25.8)
ST3 Day 365—13.6 (7.0 to 24.5)15.5 (8.4 to 26.9)3.2 (0.6 to 16.2)
ST4 Day 29—3.4 (1.0 to 11.7)3.4 (1.0 to 11.7)0.0 (0.0 to 10.7)
ST4 Day 57—55.2 (42.5 to 67.3)56.9 (44.1 to 68.8)0.0 (0.0 to 10.4)
ST4 Day 85—89.8 (79.5 to 95.3)91.2 (81.1 to 96.2)0.0 (0.0 to 10.4)
ST4 Day 180—55.2 (42.5 to 67.3)52.6 (39.9 to 65.0)0.0 (0.0 to 10.7)
ST4 Day 236—29.4 (16.8 to 46.2)25.7 (14.2 to 42.1)5.6 (1.0 to 25.8)
ST4 Day 365—16.9 (9.5 to 28.5)13.8 (7.2 to 24.9)6.5 (1.8 to 20.7)
ST5 Day 29—3.4 (1.0 to 11.7)1.7 (0.3 to 9.1)0.0 (0.0 to 10.7)
ST5 Day 57—55.2 (42.5 to 67.3)55.2 (42.5 to 67.3)0.0 (0.0 to 10.4)
ST5 Day 85—84.7 (73.5 to 91.8)87.7 (76.8 to 93.9)0.0 (0.0 to 10.4)
ST5 Day 180—51.7 (39.2 to 64.1)45.6 (33.4 to 58.4)3.1 (0.6 to 15.7)
ST5 Day 236—29.4 (16.8 to 46.2)31.4 (18.6 to 48.0)5.6 (1.0 to 25.8)
ST5 Day 365—8.5 (3.7 to 18.4)8.6 (3.7 to 18.6)3.2 (0.6 to 16.2)
ST6 Day 29—5.2 (1.8 to 14.1)5.2 (1.8 to 14.1)0.0 (0.0 to 10.7)
ST6 Day 57—51.7 (39.2 to 64.1)51.7 (39.2 to 64.1)0.0 (0.0 to 10.4)
ST6 Day 85—88.1 (77.5 to 94.1)89.5 (78.9 to 95.1)0.0 (0.0 to 10.4)
ST6 Day 180—53.4 (40.8 to 65.7)52.6 (39.9 to 65.0)6.3 (1.7 to 20.1)
ST6 Day 236—26.5 (14.6 to 43.1)28.6 (16.3 to 45.1)5.6 (1.0 to 25.8)
ST6 Day 365—15.3 (8.2 to 26.5)8.6 (3.7 to 18.6)3.2 (0.6 to 16.2)
SecondaryGMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years

GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), stratified by age group - Group 18 - 49 years. Calculations are based on number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · Geometric Mean of the Fold Rise
GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 18 - 49 Years
Geometric Mean of the Fold RiseVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 291.0 (1.0 to 1.0)1.0 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST1 Day 571.6 (1.2 to 2.1)1.7 (1.5 to 2.0)2.2 (1.8 to 2.6)1.0 (1.0 to 1.1)
ST1 Day 853.6 (2.2 to 5.6)5.3 (4.4 to 6.2)6.4 (5.3 to 7.7)1.0 (1.0 to 1.0)
ST1 Day 1801.3 (1.0 to 1.6)1.6 (1.4 to 1.8)1.7 (1.5 to 2.0)1.0 (1.0 to 1.0)
ST1 Day 2361.1 (0.9 to 1.3)1.3 (1.1 to 1.4)1.3 (1.1 to 1.6)1.0 (1.0 to 1.1)
ST1 Day 3651.0 (0.9 to 1.1)1.1 (1.1 to 1.2)1.2 (1.1 to 1.3)1.0 (1.0 to 1.1)
ST2 Day 291.0 (1.0 to 1.0)1.0 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST2 Day 573.2 (2.2 to 4.7)4.5 (3.7 to 5.4)6.0 (5.1 to 7.2)1.0 (1.0 to 1.1)
ST2 Day 858.4 (5.7 to 12.4)14.8 (12.9 to 17.0)16.0 (13.8 to 18.6)1.0 (1.0 to 1.0)
ST2 Day 1801.9 (1.4 to 2.7)3.2 (2.7 to 3.8)3.6 (3.0 to 4.2)1.0 (1.0 to 1.0)
ST2 Day 2361.2 (1.0 to 1.6)2.0 (1.7 to 2.3)1.8 (1.5 to 2.2)1.0 (1.0 to 1.0)
ST2 Day 3651.1 (1.0 to 1.2)1.2 (1.1 to 1.3)1.2 (1.1 to 1.4)1.0 (1.0 to 1.0)
ST3 Day 291.1 (1.0 to 1.2)1.0 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST3 Day 575.0 (3.2 to 7.8)6.0 (5.0 to 7.3)7.9 (6.4 to 9.7)1.0 (1.0 to 1.1)
ST3 Day 8512.1 (8.6 to 17.0)14.7 (12.7 to 16.9)16.6 (14.0 to 19.6)1.0 (1.0 to 1.0)
ST3 Day 1802.4 (1.6 to 3.6)3.0 (2.6 to 3.5)3.6 (3.0 to 4.3)1.0 (1.0 to 1.0)
ST3 Day 2361.6 (1.2 to 2.2)1.8 (1.5 to 2.1)2.0 (1.6 to 2.4)1.0 (1.0 to 1.0)
ST3 Day 3651.2 (1.0 to 1.4)1.3 (1.2 to 1.4)1.4 (1.2 to 1.6)1.0 (1.0 to 1.0)
ST4 Day 291.0 (1.0 to 1.1)1.0 (1.0 to 1.1)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST4 Day 572.1 (1.5 to 3.0)2.7 (2.3 to 3.2)3.5 (2.9 to 4.2)1.0 (1.0 to 1.0)
ST4 Day 855.4 (3.5 to 8.5)8.6 (7.5 to 9.8)10.2 (8.6 to 12.0)1.0 (1.0 to 1.0)
ST4 Day 1801.5 (1.1 to 2.1)2.3 (2.0 to 2.7)2.6 (2.2 to 3.1)1.0 (1.0 to 1.1)
ST4 Day 2361.2 (0.9 to 1.5)1.7 (1.4 to 2.0)1.7 (1.4 to 2.0)1.0 (1.0 to 1.0)
ST4 Day 3651.1 (1.0 to 1.2)1.3 (1.2 to 1.4)1.3 (1.2 to 1.5)1.0 (1.0 to 1.0)
ST5 Day 291.0 (1.0 to 1.0)1.0 (1.0 to 1.0)1.0 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST5 Day 572.1 (1.5 to 3.0)2.8 (2.4 to 3.3)4.0 (3.3 to 4.8)1.0 (1.0 to 1.0)
ST5 Day 855.7 (3.8 to 8.7)9.0 (7.8 to 10.3)10.8 (9.1 to 12.8)1.0 (1.0 to 1.0)
ST5 Day 1801.3 (1.0 to 1.7)2.1 (1.8 to 2.4)2.7 (2.3 to 3.2)1.0 (1.0 to 1.0)
ST5 Day 2361.1 (0.9 to 1.3)1.6 (1.4 to 1.8)1.6 (1.4 to 2.0)1.0 (1.0 to 1.0)
ST5 Day 3651.1 (1.0 to 1.2)1.2 (1.1 to 1.3)1.3 (1.1 to 1.4)1.0 (1.0 to 1.0)
ST6 Day 291.0 (1.0 to 1.0)1.1 (1.0 to 1.1)1.0 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST6 Day 572.0 (1.4 to 2.8)2.6 (2.2 to 3.1)3.4 (2.8 to 4.2)1.0 (1.0 to 1.1)
ST6 Day 855.4 (3.6 to 8.3)9.1 (7.9 to 10.4)10.6 (9.0 to 12.5)1.0 (1.0 to 1.0)
ST6 Day 1801.4 (1.1 to 1.9)2.3 (2.0 to 2.6)2.5 (2.2 to 3.0)1.0 (1.0 to 1.0)
ST6 Day 2361.2 (1.0 to 1.5)1.7 (1.5 to 2.0)1.7 (1.4 to 2.0)1.0 (1.0 to 1.1)
ST6 Day 3651.1 (1.0 to 1.3)1.2 (1.1 to 1.4)1.3 (1.2 to 1.5)1.0 (1.0 to 1.1)
SecondaryGMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years

GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6), stratified by age group - Group 50 - 65 years. Calculations are based on number of subjects with non-missing results.

Time frame:
up to Day 365 / Month 12
Reported as:
Geometric mean · Geometric Mean of the Fold Rise
GMFRs (Geometric Mean of the Fold Rise as Compared to Baseline) for IgG (Immunoglobulin G) Against Each OspA (Outer Surface Protein A) Serotype (ST1 to ST6) - Group 50 - 65 Years
Geometric Mean of the Fold RiseVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
ST1 Day 29—1.2 (1.0 to 1.4)1.0 (1.0 to 1.1)1.0 (1.0 to 1.1)
ST1 Day 57—2.1 (1.6 to 2.8)1.8 (1.4 to 2.3)1.0 (0.9 to 1.1)
ST1 Day 85—4.5 (3.3 to 6.1)4.5 (3.3 to 6.0)1.0 (1.0 to 1.1)
ST1 Day 180—1.7 (1.4 to 2.1)1.6 (1.3 to 1.9)1.0 (1.0 to 1.1)
ST1 Day 236—1.2 (1.0 to 1.5)1.3 (1.1 to 1.5)1.0 (1.0 to 1.1)
ST1 Day 365—1.2 (1.0 to 1.3)1.1 (1.0 to 1.2)1.0 (0.9 to 1.1)
ST2 Day 29—1.1 (0.9 to 1.3)1.1 (1.0 to 1.2)1.0 (1.0 to 1.1)
ST2 Day 57—4.4 (3.2 to 6.1)4.1 (3.0 to 5.5)1.0 (1.0 to 1.1)
ST2 Day 85—12.3 (9.5 to 15.8)13.3 (10.2 to 17.2)1.0 (1.0 to 1.1)
ST2 Day 180—2.9 (2.3 to 3.8)2.9 (2.2 to 3.7)1.0 (1.0 to 1.1)
ST2 Day 236—1.5 (1.2 to 1.9)1.6 (1.2 to 2.2)1.0 (1.0 to 1.0)
ST2 Day 365—1.2 (1.1 to 1.5)1.2 (1.1 to 1.4)1.0 (1.0 to 1.1)
ST3 Day 29—1.1 (1.0 to 1.4)1.0 (1.0 to 1.0)1.1 (0.9 to 1.2)
ST3 Day 57—6.1 (4.3 to 8.7)5.9 (4.3 to 8.2)1.1 (0.9 to 1.2)
ST3 Day 85—12.5 (9.6 to 16.4)12.8 (9.7 to 17.0)1.1 (0.9 to 1.2)
ST3 Day 180—3.3 (2.6 to 4.2)3.0 (2.3 to 3.8)1.1 (1.0 to 1.2)
ST3 Day 236—1.7 (1.3 to 2.2)1.8 (1.4 to 2.5)1.1 (0.9 to 1.3)
ST3 Day 365—1.3 (1.1 to 1.5)1.2 (1.1 to 1.4)1.1 (0.9 to 1.2)
ST4 Day 29—1.1 (0.9 to 1.3)1.1 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST4 Day 57—2.7 (2.0 to 3.7)2.6 (2.0 to 3.3)1.0 (1.0 to 1.0)
ST4 Day 85—7.4 (5.7 to 9.7)7.9 (6.1 to 10.2)1.0 (1.0 to 1.0)
ST4 Day 180—2.2 (1.8 to 2.8)2.1 (1.7 to 2.5)1.0 (1.0 to 1.0)
ST4 Day 236—1.4 (1.2 to 1.7)1.4 (1.1 to 1.7)1.1 (0.9 to 1.2)
ST4 Day 365—1.2 (1.0 to 1.4)1.1 (1.0 to 1.3)1.1 (1.0 to 1.2)
ST5 Day 29—1.1 (0.9 to 1.2)1.0 (1.0 to 1.1)1.0 (1.0 to 1.0)
ST5 Day 57—2.9 (2.1 to 3.8)2.8 (2.1 to 3.6)1.0 (1.0 to 1.0)
ST5 Day 85—7.8 (5.9 to 10.3)8.1 (6.2 to 10.6)1.0 (1.0 to 1.0)
ST5 Day 180—2.2 (1.8 to 2.8)2.0 (1.6 to 2.6)1.0 (1.0 to 1.1)
ST5 Day 236—1.4 (1.2 to 1.8)1.5 (1.2 to 1.9)1.1 (0.9 to 1.2)
ST5 Day 365—1.1 (1.0 to 1.3)1.1 (1.0 to 1.2)1.0 (1.0 to 1.1)
ST6 Day 29—1.1 (0.9 to 1.2)1.1 (1.0 to 1.2)1.0 (1.0 to 1.0)
ST6 Day 57—2.6 (1.9 to 3.4)2.6 (2.0 to 3.4)1.0 (1.0 to 1.0)
ST6 Day 85—7.9 (6.1 to 10.4)8.7 (6.7 to 11.3)1.0 (1.0 to 1.0)
ST6 Day 180—2.3 (1.9 to 2.9)2.3 (1.8 to 2.9)1.1 (1.0 to 1.2)
ST6 Day 236—1.4 (1.1 to 1.7)1.5 (1.2 to 1.9)1.1 (0.9 to 1.3)
ST6 Day 365—1.2 (1.0 to 1.3)1.1 (1.0 to 1.3)1.1 (1.0 to 1.2)
SecondaryPercentage of Participants With SAEs (Serious Adverse Events)

Frequency of SAEs (Serious Adverse Events) during the entire study; frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With SAEs (Serious Adverse Events)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With SAEs (Serious Adverse Events)0.0 (0.0 to 11.7)1.9 (0.7 to 4.7)2.4 (1.0 to 5.6)2.4 (0.8 to 6.9)
SecondaryPercentage of Participants With Related SAEs (Serious Adverse Events)

Frequency of related SAEs (Serious Adverse Events) during the entire study; frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With Related SAEs (Serious Adverse Events)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With Related SAEs (Serious Adverse Events)0.0 (0.0 to 11.7)0.0 (0.0 to 1.8)0.0 (0.0 to 1.8)0.0 (0.0 to 3.0)
SecondaryPercentage of Participants With AESIs (Adverse Events of Special Interest)

Frequency of AESIs (Adverse Events of Special Interest) during the entire study; frequency is being assessed in terms of percentage of participants. AESIs are cases of Lyme Diseases, Lyme associated Events and the onset of potentially autoimmune or neuro-inflammatory disorders.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With AESIs (Adverse Events of Special Interest)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With AESIs (Adverse Events of Special Interest)0.0 (0.0 to 11.7)1.9 (0.7 to 4.7)0.5 (0.1 to 2.7)0.0 (0.0 to 3.0)
SecondaryPercentage of Participants With Related AESIs (Adverse Events of Special Interest)

Frequency of related AESIs (Adverse Events of Special Interest) during the entire study; frequency is being assessed in terms of percentage of participants. AESIs are cases of Lyme Diseases, Lyme associated Events and the onset of potentially autoimmune or neuro-inflammatory disorders.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With Related AESIs (Adverse Events of Special Interest)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With Related AESIs (Adverse Events of Special Interest)0.0 (0.0 to 11.7)0.5 (0.1 to 2.6)0.0 (0.0 to 1.8)0.0 (0.0 to 3.0)
SecondaryPercentage of Participants With Unsolicited AEs (Adverse Events)

Frequency of unsolicited AEs (Adverse Events) during the entire study (incl. clinically relevant laboratory parameters); frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With Unsolicited AEs (Adverse Events)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With Unsolicited AEs (Adverse Events)27.6 (14.7 to 45.7)51.9 (45.2 to 58.5)56.6 (49.7 to 63.2)51.6 (42.9 to 60.2)
SecondaryPercentage of Participants With Related Unsolicited AEs (Adverse Events)

Frequency of related unsolicited AEs (Adverse Events) during the entire study (incl. clinically relevant laboratory parameters); frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With Related Unsolicited AEs (Adverse Events)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Percentage of Participants With Related Unsolicited AEs (Adverse Events)6.9 (1.9 to 22.0)9.3 (6.1 to 14.0)14.6 (10.4 to 20.1)8.9 (5.0 to 15.2)
SecondaryPercentage of Participants With Solicited Local and Solicited Systemic AEs (Adverse Events)

Frequency of solicited local and solicited systemic AEs (Adverse Events) within 7 days after each and after any vaccination; frequency is being assessed in terms of percentage of participants.

Time frame:
Day 1 (day of first vaccination) through Day 7; Day 29 (day of second vaccination) through Day 35; Day 57 (day of third vaccination) through Day 63
Reported as:
Number · percentage of participants
Percentage of Participants With Solicited Local and Solicited Systemic AEs (Adverse Events)
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Solicted Local AEs89.7 (73.6 to 96.4)93.0 (88.8 to 95.7)96.1 (92.5 to 98.0)29.8 (22.5 to 38.4)
Solicited Systemic AEs62.1 (44.0 to 77.3)67.8 (61.2 to 73.7)71.7 (65.2 to 77.4)42.7 (34.4 to 51.5)
SecondaryPercentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 18-49

Frequency of SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), solicited and unsolicited AEs (Adverse Events) during the entire study stratified by age group - Group 18-49; frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 18-49
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
SAEs0.0 (0.0 to 11.7)2.0 (0.7 to 5.8)2.1 (0.7 to 5.9)1.1 (0.2 to 6.0)
AESIs0.0 (0.0 to 11.7)0.7 (0.1 to 3.8)0.0 (0.0 to 2.6)0.0 (0.0 to 4.1)
solicited AEs89.7 (73.6 to 96.4)93.9 (88.8 to 96.7)96.6 (92.2 to 98.5)56.0 (45.8 to 65.8)
unsolicited AEs27.6 (14.7 to 45.7)49.0 (41.0 to 57.0)55.2 (47.0 to 63.0)50.5 (40.5 to 60.6)
SecondaryPercentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 50-65 Years

Frequency of SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) during the entire study stratified by age group - Group 50-65 years; frequency is being assessed in terms of percentage of participants.

Time frame:
up to Day 365 / Month 12
Reported as:
Number · percentage of participants
Percentage of Participants With SAEs (Serious Adverse Events), AESIs (Adverse Events of Special Interest), Solicited and Unsolicited AEs (Adverse Events) - Group 50-65 Years
percentage of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
SAEs—1.5 (0.3 to 8.0)3.3 (0.9 to 11.4)6.1 (1.7 to 19.6)
AESIs—4.5 (1.5 to 12.4)1.7 (0.3 to 8.9)0.0 (0.0 to 10.4)
solicited AEs—92.5 (83.7 to 96.8)96.7 (88.6 to 99.1)51.5 (35.2 to 67.5)
unsolicited AEs—58.2 (46.3 to 69.3)60.0 (47.4 to 71.4)54.5 (38.0 to 70.2)
SecondaryNumber of Participants With AESIs (Adverse Events of Special Interest) up to Study End
Time frame:
up to Day 365 / Month 12
Reported as:
Number · Number of participants
Number of Participants With AESIs (Adverse Events of Special Interest) up to Study End
Number of participantsVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Any AE of Special Interest0410.
Lyme disease0200
Erythema migrans0100
Osteoarthritis0100
Polyarthritis0010

Adverse events

Collected over up to Day 365. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
VLA15 Low Dose0/29 (0%)0/29 (0%)26/29 (89.7%)
VLA15 Medium Dose0/214 (0%)4/214 (1.9%)203/214 (94.9%)
VLA15 High Dose0/205 (0%)5/205 (2.4%)202/205 (98.5%)
Placebo0/124 (0%)3/124 (2.4%)85/124 (68.5%)
Most frequent serious events
Showing 10 of 13
Most frequent serious events
EventVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
DiverticulitisInfections and infestations0/290/2140/2051/124
NeurosyphilisInfections and infestations0/290/2140/2051/124
Acute myocardial infarctionCardiac disorders0/290/2140/2051/124
Biliary colicHepatobiliary disorders0/290/2140/2051/124
Herpes zosterInfections and infestations0/290/2141/2050/124
Multiple injuriesInjury, poisoning and procedural complications0/290/2141/2050/124
Upper limb fractureInjury, poisoning and procedural complications0/290/2141/2050/124
PlasmacytomaNeoplasms benign, malignant and unspecified (incl cysts and polyps)0/290/2141/2050/124
Peripheral arterial occlusive diseaseVascular disorders0/290/2141/2050/124
CellulitisInfections and infestations0/291/2140/2050/124
Most frequent other events
Showing 10 of 13
Most frequent other events
EventVLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlacebo
Injection site painGeneral disorders26/29198/214196/20530/124
MyalgiaMusculoskeletal and connective tissue disorders15/29106/21497/20521/124
HeadacheNervous system disorders10/2973/21484/20533/124
FatigueGeneral disorders8/2966/21481/20529/124
Injection site erythemaGeneral disorders8/2968/21472/20512/124
Injection site swellingGeneral disorders4/2957/21468/2054/124
Injection site indurationGeneral disorders3/2964/21465/2052/124
Influenza like illnessGeneral disorders3/2932/21442/20520/124
ArthralgiaMusculoskeletal and connective tissue disorders2/2942/21437/20512/124
NauseaGastrointestinal disorders5/2923/21432/20511/124

Baseline characteristics

Age, Continuous
Age, Continuous(years)VLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlaceboTotal
Mean29.2 ± 6.1341.7 ± 13.2641.6 ± 12.5640.7 ± 12.8040.8 ± 12.90
Sex: Female, Male
Sex: Female, Male(Participants)VLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlaceboTotal
Female1611710871312
Male13979753260
Race/Ethnicity, Customized
Race/Ethnicity, Customized(number of participants)VLA15 Low DoseVLA15 Medium DoseVLA15 High DosePlaceboTotal
American Indian or Alaska Native01001
Asian02002
Black or African American436417
Native Hawaiian or Other Pacific Islander00000
White25208196120549
Other00303
08

Study locations

9 sites
  • Clinical Research Consulting, LLC
    Milford, Connecticut 06460, United States
  • Stamford Therapeutics Consortium
    Stamford, Connecticut 06905, United States
  • United Medical Associates
    Binghamton, New York 13901, United States
  • Regional Clinical Research, Inc.
    Endwell, New York 13706, United States
  • Rochester Clinical Research Inc.
    Rochester, New York 14609, United States
  • Omega Medical Research
    Warwick, Rhode Island 02886, United States
  • Cevac Center for vaccinology
    Gent, 9000, Belgium
  • Berliner Centrum für Reise- und Tropenmedizin (BCRT)
    Berlin, 10117, Germany
  • Universitätsklinikum Hamburg-Eppendorf
    Hamburg, 20359, Germany
09

References and documents

Study documents

  • Study protocol · Jun 13, 2019
  • Statistical analysis plan · Apr 17, 2020

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jan 10, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT03769194
Lead sponsor
Pfizer
Responsible party
Sponsor
First posted
Dec 7, 2018
Start date
Dec 17, 2018
Primary completion
Dec 18, 2019
Completion
Oct 2, 2020
Results posted
Jun 30, 2021
Last update
Jan 10, 2023

Study contacts

Pfizer CT.gov Call Center
study director · Pfizer

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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