Valneva has announced final Phase 2 results from its VLA15-221 study of Lyme disease vaccine candidate VLA15, showing a robust immune response and favorable safety profile six months after a third booster dose. The findings support the potential benefits of yearly vaccination ahead of each Lyme season.

Pfizer and Valneva have been collaborating on VLA15’s development and commercialization since April 2020. If approved, VLA15 would become the first human vaccine for Lyme disease, a growing public health concern with an estimated 476,000 U.S. diagnoses and treatments annually, and 132,000 cases reported in Europe.

Juan Carlos Jaramillo, Chief Medical Officer of Valneva, said: “These final Phase 2 data are consistent with those reported previously and confirm the potential benefits of booster doses across all evaluated age groups. Lyme disease continues to expand geographically and remains a pressing unmet medical need affecting communities across the Northern Hemisphere. Each set of positive results moves us closer to the possibility of making this vaccine available to adults, adolescents and children living in Lyme-endemic areas.”

The study found that an additional booster immediately increased antibody levels, which remained well above baseline six months post-vaccination. “The results further validate the use of the three-dose vaccination schedule and a yearly booster dose, already included in the Phase 3 protocols,” the company noted.

Safety remained strong, with no concerns observed by the independent Data Monitoring Committee across any age group or dosing schedule. 

VLA15, a multivalent protein subunit vaccine, targets the outer surface protein A (OspA) of Borrelia burgdorferi, blocking the bacteria from leaving ticks and infecting humans.

The vaccine covers the six most prevalent OspA serotypes in North America and Europe and is currently the most advanced Lyme disease candidate in clinical development, with two Phase 3 trials underway.

Lyme disease, transmitted by infected Ixodes ticks, is the most common vector-borne illness in the Northern Hemisphere.