Valneva and Pfizer report further positive results from Phase 2 booster study for vaccine candidates against Lyme disease

• VLA15-221 Phase 2 study: Strong immune response one month after a second booster dose (month 31) in children and adults
• Significant anamnestic antibody response observed in all six serotypes, consistent with previous findings
• Favorable safety profile of VLA15 observed in all age groups and for all vaccinations

Saint-Herblain (France) and New York, NY, September 3, 2024 – Valneva SE (Nasdaq: VALN; Euronext Paris: VLA) and Pfizer Inc. (NYSE: PFE) today announced positive immunogenicity and safety data from their VLA15-221 Phase 2 study following a second booster dose of their Lyme disease vaccine candidate VLA15 administered one year after receiving the first booster dose. The immune response and safety profile of VLA15 one month after receiving the second booster dose were similar to those seen after receiving the first booster dose and demonstrated compatibility with the expected benefit of a booster dose prior to each Lyme disease season. There are currently no approved human vaccines against Lyme disease, and VLA15 is the Lyme disease vaccine candidate furthest along in clinical development; two Phase 3 trials are currently ongoing. The Centers for Disease Control and Prevention (CDC) estimates that approximately 476,000 people in the United States become infected with Lyme disease and receive treatment each year, and 129,000 cases are reported annually in Europe.^1,2

These latest results from the Phase 2 VLA15-221 study again demonstrated significant anamnestic antibody response across all six serotypes covered by the vaccine candidate in pediatric (5 to 11 years) and adolescent (12 to 17 years) participants, as well as in adults (18 to 65 years), measured one month after administration of this second booster dose (month 31). A high proportion of participants seroconverted after the second booster dose, resulting in seroconversion rates^* (SCRs) above 90% for all outer surface protein A (OspA) serotypes in all age groups, consistent with the SCRs after the first booster dose. Geometric mean titres one month after the first and second booster doses (ie, month 19 versus month 31) were comparatively high.