Lyme disease is the most common vector-borne disease in the Northern Hemisphere1. It is caused by Borrelia bacteria transmitted to humans by infected Ixodes ticks2. According to the U.S. Centers for Disease Control and Prevention (CDC), approximately 476,000 Americans are diagnosed and treated for Lyme disease each year with at least a further 200,000 cases in Europe3,4.

VLA15 – Valneva’s Lyme disease vaccine candidate

  • VLA15 is currently the only active vaccine program in clinical development against Lyme disease.
  • VLA15 is a multivalent recombinant protein vaccine that targets six serotypes of Borrelia representing the most common pathogenic strains found in the United States and Europe.
  • Valneva has completed recruitment and reported initial results for two Phase 2 clinical trials [5,6] of VLA15 in over 800 healthy adults and in which Valneva observed high levels of antibodies against all six serotypes.
  • Valneva announced a collaboration with Pfizer for late phase development and, if approved, commercialization of VLA15 [7].
  • As part of its collaboration with Pfizer, Valneva accelerated the pediatric development of VLA15 with an additional Phase 2 clinical trial initiated in March 2021. In July 2021, Pfizer and Valneva announced recruitment completion for VLA15-221 with a total of 625 participants, 5 to 65 years of age [8].
  • The VLA15 program was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in July 2017 [9].

Additional information about Lyme disease:

  1. Lyme borreliosis in Europe: influences of climate and climate change, epidemiology, ecology and adaptation measures (2006), Retrieved from, Accessed 02-Oct-2021
  2. Stanek et al. 2012, The Lancet 379:461–473
  3. How many people get Lyme disease? | Lyme Disease | CDC. (n.d.). Retrieved from
  4. Estimated from available national data. Number largely underestimated based on WHO Europe Lyme Report as case reporting is highly inconsistent in Europe and many LB infections go undiagnosed; ECDC tick-borne-diseases- meeting-report
  5. Valneva press release: Valneva Announces Positive Initial Results for Phase 2 Study of Lyme Disease Vaccine Candidate
  6. Valneva press release: Valneva Announces Positive Initial Results for Second Phase 2 Study of Lyme Disease Vaccine Candidate VLA15
  7. Valneva press release: Valneva and Pfizer Announce Collaboration to Co-Develop and Commercialize Lyme Disease Vaccine, VLA15
  8. Valneva press release: Valneva and Pfizer Complete Recruitment for Phase 2 Trial of Lyme Disease Vaccine Candidate
  9. Valneva press release: Valneva Receives FDA Fast Track Designation for its Lyme Disease Vaccine Candidate VLA15