The vaccine targets the outer surface protein A of Borrelia burgdorferi, which is the bacteria that cause Lyme disease.
Data from a phase 2 trial for the Lyme disease vaccine candidate VLA15 (Valneva/Pfizer) show promise, therefore a planned phase 3 clinical trial will now evaluate a 3-dose primary series vaccination schedule, according to a Pfizer press release.
The trial will evaluate VLA15 in adults and pediatric subjects 5 years of age and older.
VLA15 is the only Lyme disease vaccine candidate currently in clinical development, according to Pfizer. VLA15 is defined as a multivalent protein subunit vaccine that uses an established mechanism of action for Lyme disease. The vaccine targets the outer surface protein A of Borrelia burgdorferi, which is the bacteria that cause Lyme disease.
The phase 2 trial, VLA15-221, compared the immunogenicity of VLA15 after administration of 2 or 3 primary series doses in groups 5-11 years of age, 12-17 years of age, and 18-65 years of age. In a sub-analysis of adult participants (18-65 years of age) who received VLA15 in either the 2- or the 3-dose schedule, performed 1 month after the last vaccination dose, VLA15 was found to be immunogenic with both vaccination schedules tested. These data are consistent with the strong immunogenicity profile observed for this age group in previous phase 2 studies.
Further, the induction of anti-OspA IgG (anti-outer surface protein A immunoglobulin G) antibody titers was higher in participants who received the 3-dose primary series compared to those who received the 2-dose primary series, supporting the use of a 3-dose primary series schedule in the planned phase 3 clinical trial, according to the researchers.
The VLA15-221 trial is ongoing to assess the safety and immunogenicity of VLA15 in participants 5 to 17 years of age, and the initial pediatric data are expected in the first half of 2022.
Valneva and Pfizer report further positive phase 2 data for Lyme disease vaccine candidate. Pfizer. February 4, 2022. Accessed February 4, 2022. https://www.pfizer.com/news/press-release/press-release-detail/valneva-and-pfizer-report-further-positive-phase-2-data