A Phase 3, Randomized, Placebo-Controlled Study to Evaluate Safety and Immune Response of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine, VLA15, in Healthy Participants Aged 7 Years and Older

What this Trial Is About

Researchers are studying the safety and immune response of a fifth dose of the Lyme disease vaccine called VLA15 in healthy individuals aged 7 years and older who have already received four doses of this vaccine. This Phase 3 trial compares the effects of the vaccine against a placebo (saline) to better understand its protection against Lyme disease. The study is randomized, placebo-controlled, and double-blinded, aiming to assess tolerability and immune response. Participants receive one injection, either VLA15 or saline, into the muscle of the upper arm at their first visit. They are randomized in a 5:1 ratio to either vaccine or placebo. The timing of the fifth dose varies, occurring either one or two years after the fourth dose from a previous study. The trial includes about 1712 participants and uses an independent data monitoring committee to oversee safety. During approximately 12 months of participation, individuals will attend four clinic visits. These visits include health checks, blood draws to measure immune response, and receiving the study injection during the first visit. Researchers will monitor local and systemic reactions within seven days post-injection, adverse events up to one month, and longer-term safety for up to a year. The main outcomes focus on immune responses to different parts of the vaccine and recording any side effects or new medical conditions.

A Study to Learn About the Safety, Tolerability, and Immunogenicity of a Fifth Dose of 6-Valent OspA-Based Lyme Disease Vaccine