Lyme Disease Vaccine for Lyme Disease

(VALOR Trial)

Not currently recruiting at 162 trial locations

Overseen By Pfizer CT.gov Call Center

Age: Any Age

Sex: Any

Trial Phase: Phase 3

Sponsor: Pfizer

Must not be taking: Tetracyclines, Chronic antibiotics

Disqualifiers: Pregnancy, Recent Lyme disease, others

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 11

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new vaccine, VLA15, to determine its effectiveness in preventing Lyme disease. Researchers are testing the vaccine in people living in areas where Lyme disease is common, such as regions with many ticks. Participants will receive either the vaccine or a placebo (a harmless saltwater shot) to compare health outcomes. This trial suits individuals who spend significant time outdoors and may encounter ticks, particularly those in jobs like landscaping or with hobbies like hiking. Participants will attend several visits and calls over approximately two and a half years. As a Phase 3 trial, this is the final step before FDA approval, offering participants the opportunity to contribute to a potentially groundbreaking Lyme disease prevention method.

Do I need to stop my current medications to join the trial?

The trial does not specify if you need to stop taking your current medications, but it does exclude people who are using certain antibiotics like doxycycline or minocycline for acne or other conditions. If you're on these medications, you might not be eligible to participate.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research has shown that the Lyme disease vaccine candidate, VLA15, was safe in earlier studies. Participants, including both children and adults, generally tolerated the vaccine well. Reports noted that side effects were similar whether participants received one or two booster shots. The most common side effects were mild, such as soreness at the injection site and slight fatigue. No serious safety issues were linked to the vaccine. These findings suggest VLA15 is safe, but ongoing studies are verifying these results with larger groups. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Researchers are excited about VLA15 for Lyme disease because it's a vaccine, which is a promising tool in preventing the disease rather than just treating it after infection. Unlike antibiotics, which are the current standard treatment for Lyme disease and can only be used after the infection has occurred, VLA15 aims to stop the disease before it starts. This vaccine targets the outer surface protein A (OspA) of Borrelia bacteria, the cause of Lyme disease, and could provide immunity through a series of doses. This preventive approach could significantly reduce the incidence of Lyme disease, especially in areas where it's prevalent.

What evidence suggests that this trial's treatments could be effective for Lyme disease?

Research has shown that the VLA15 vaccine for Lyme disease is promising. Studies indicate that after three doses, the vaccine can be up to 71% effective in preventing Lyme disease. Participants, including children and teens, demonstrated strong immune responses and safety after receiving the vaccine. The vaccine helps the body recognize and fight the infection using a protein from the Lyme bacteria. This trial will test different lots of the VLA15 vaccine, each administered as a 3-dose primary vaccination series with a booster dose. If VLA15 proves as effective as earlier studies suggest, it could greatly reduce Lyme disease cases. ^{2 3 6 7 8}

Who Is on the Research Team?

Pfizer CT.gov Call Center

Principal Investigator

Pfizer

Are You a Good Fit for This Trial?

This trial is for healthy individuals aged 5 and older who are often in Lyme disease-endemic areas due to outdoor activities or living conditions. It's not for those with recent Lyme disease, known tick bites within the last month, chronic use of certain antibiotics, pregnant or breastfeeding women, or people with unstable health conditions that could confuse Lyme disease assessment.

Inclusion Criteria

I work in an area or job (like landscaping or forestry) that has a high risk of tick exposure.

Participants who reside in areas with endemic Lyme disease and who lead lifestyles that put them at increased risk for Lyme disease

Individuals who pursue recreational activities such as hiking, camping, fishing, hunting, jogging, or gardening in such areas

Exclusion Criteria

I was diagnosed with Lyme disease in the last 3 months.

I have had Lyme disease affecting my heart, nervous system, joints, or it has spread throughout my body.

I am taking long-term antibiotics like doxycycline for acne or other conditions.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Primary Vaccination Series

Participants receive a 3-dose primary vaccination series at 0, 2, and 5 to 9 months

5 to 9 months

3 visits (in-person)

Booster Dose

Participants receive a booster dose about 12 months after the end of the primary vaccination series

1 month

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the booster dose

Up to 2 and a half years

At least 7 visits (in-person), 5 telephone contacts

Extended Follow-up

A subset of participants is followed for a third Lyme disease season

Up to 3 and a half years

What Are the Treatments Tested in This Trial?

Interventions

• VLA15

Trial Overview The study tests a new vaccine called VLA15 against saline (a saltwater placebo) to prevent Lyme disease. Participants will be randomly assigned to receive either the vaccine or placebo in a series of three initial doses followed by a booster dose before peak Lyme seasons over approximately two and a half years.

How Is the Trial Designed?

Group I: VLA15 Lot 3 (3-dose primary vaccination series and booster dose) Experimental Treatment 1 Intervention

Shot in the deltoid muscle (preferable in the nondominant arm)

Group II: VLA15 Lot 2 (3-dose primary vaccination series and booster dose) Experimental Treatment 1 Intervention

Shot in the deltoid muscle (preferable in the nondominant arm)

Group III: VLA15 Lot 1 (3-dose primary vaccination series and booster dose) Experimental Treatment 1 Intervention

Shot in the deltoid muscle (preferable in the nondominant arm)

Group IV: Placebo (3-dose primary vaccination series and booster dose) Placebo Group 1 Intervention

Shot in the deltoid muscle (preferable in the nondominant arm)

Who Is Running the Clinical Trial?

Pfizer

Lead Sponsor

Trials

4,712

Recruited

50,980,000+

Known For

Vaccine Innovations

Top Products

Viagra, Zoloft, Lipitor, Prevnar 13

Albert Bourla

Pfizer

Chief Executive Officer since 2019

PhD in Biotechnology of Reproduction, Aristotle University of Thessaloniki

Patrizia Cavazzoni

Pfizer

Chief Medical Officer

MD from McGill University

Valneva Austria GmbH

Industry Sponsor

Trials

46

Recruited

59,100+

Published Research Related to This Trial

The only FDA-approved Lyme disease vaccine, based on the OspA protein, was effective in generating immunity against the disease but was withdrawn from the market in 2002 due to the need for booster doses and issues with false positive test results.

New clinical trials are currently underway for a multivalent OspA vaccine aimed at providing better protection against Lyme disease in both the United States and Europe.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A brief history of OspA vaccines including their impact on diagnostic testing for Lyme disease. Wormser, GP.[2022]

Citations

1. valneva.com valneva.com/wp-content/uploads/2025/09/2025_09_02_VLA15-221_m42_PR_EN_Final-1.pdf

Valneva Reports Further Positive Phase 2 Safety and ... The strong anamnestic immune response and favorable safety profile following a third booster dose were consistent with those reported after ...

2. thelancet.com thelancet.com/journals/laninf/article/PIIS1473-3099(25)00160-4/fulltext?rss=yes

Lyme borreliosis vaccine VLA15 tested safe and ... If the efficacy of VLA15 meets or potentially exceeds the 76% observed in the phase 3 study of LYMErix,

3. valneva.com valneva.com/research-development/lyme-disease/

Lyme Disease - VLA15 - Valneva Valneva and Pfizer reported positive pediatric and adolescent immunogenicity and safety data for VLA15, when given as a booster [7]. In September 2025, ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1473309925000921

Immunogenicity and safety of different immunisation ... Immune responses in children and adolescents after the second dose of VLA15 when administered with a 0–2–6-month schedule were at least as high as those in ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8364756/

Clinical Effectiveness of Lyme Vaccine: A Matched Case– ... We found ≥3 doses to be 71% effective against Lyme disease. This is the first study to show that the Lyme vaccine is effective in a real-world setting.

6. valneva.com valneva.com/press-release/valneva-reports-further-positive-phase-2-safety-and-immunogenicity-results-for-lyme-disease-vaccine-candidate/

Valneva Reports Further Positive Phase 2 Safety and ... Strong immune response after third yearly booster dose in children and adults · Significant anamnestic antibody response across all six serotypes ...

7. thelancet.com thelancet.com/journals/laninf/article/PIIS1473-3099(24)00372-4/abstract

Immunogenicity and safety of an 18-month booster dose ... A booster dose of VLA15 is safe and induces substantial anamnestic immune responses against all six OspA serotypes. As with previously ...

8. pfizer.com pfizer.com/news/press-release/press-release-detail/valneva-and-pfizer-report-further-positive-phase-2-booster

Valneva and Pfizer Report Further Positive Phase 2 ... The safety and tolerability profile of VLA15 after a second booster dose was comparable to the profile observed after the first booster.