Lyme disease is the most common vector-borne illness in the Northern Hemisphere1,2. It is caused by Borrelia bacteria transmitted to humans by infected Ixodes ticks3. According to the U.S. Centers for Disease Control and Prevention (CDC), approximately 300,000 Americans are diagnosed with Lyme disease each year with at least a further 200,000 cases in Europe1,2.

About VLA15

  • Valneva and Pfizer announced a collaboration to develop and commercialize VLA15 in April 2020.4
  • VLA15 is currently the only active vaccine program in clinical development against Lyme disease.
  • VLA15 is in Phase 2 clinical development5: Valneva announced positive initial results for its two Phase 2 studies, VLA15-2016 and VLA15-2027, in July and October 2020 respectively. Valneva and Pfizer plan to accelerate pediatric development of VLA15, with the initiation of study VLA15-221 in the first quarter of 2021, subject to regulatory approval.8
  • The VLA15 program was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in July 2017.9
  • VLA15 is a multivalent, protein subunit vaccine that targets the outer surface protein A (OspA) of Borrelia, an established mechanism of action for Lyme disease vaccine. OspA is one of the most dominant surface proteins expressed by the bacteria when present in a tick.

Additional information about Lyme disease:

  1. How many people get Lyme disease? | Lyme Disease | CDC. (n.d.). Retrieved from
  2. 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
  3. Stanek et al. 2012, The Lancet 379:461–473
  4. Valneva press release: Valneva and Pfizer Announce Collaboration to Co-Develop and Commercialize Lyme Disease Vaccine, VLA15
  5. Valneva press release: Valneva Initiates Phase 2 Clinical Development For Its Lyme Disease Vaccine Candidate 
  6. Valneva press release: Valneva Announces Positive Initial Results for Phase 2 Study of Lyme Disease Vaccine Candidate
  7. Valneva press release: Valneva Announces Positive Initial Results for Second Phase 2 Study of Lyme Disease Vaccine Candidate VLA15
  8. Valneva press release: Valneva Announces Acceleration of Pediatric Development for Lyme Disease Vaccine Candidate
  9. Valneva press release: Valneva Receives FDA Fast Track Designation for its Lyme Disease Vaccine Candidate VLA15