Tdap and Biomarkers of Alzheimer's Disease

A growing number of studies have consistently shown reduced incident risk of dementia associated with a variety of vaccinations. Most recently, data probes of medical claims from two large and disparate databases showed that vaccination for tetanus, diphtheria and pertussis (Tdap) was associated with a 42% decrease in dementia. Adult vaccination coverage remains low for most routinely recommended vaccines, including Tdap. This study will screen and qualify participants who do not meet the recommended frequency interval for Tdap vaccination. Participants will have consented to a review of their medical history (including vaccination history), a neurocognitive test and a battery of blood tests. Included in the blood testing will be plasma-based testing for amyloid, tau and neurofilament light protein. The study will be considered a pilot study; it will be an open-label trial. All participants will receive a single dose of the Tdap vaccine. Nine months after vaccination, participants will repeat the pre-vaccine blood tests. Primary objective will be the assessment of change in the Alzheimer's disease (AD) biomarkers. Bordetella pertussis (B. pertussis), the bacterium that causes whopping cough, is one of the targets of the Tdap vaccine. B. pertussis is a hypothesized infectious trigger of Alzheimer's disease (AD). A secondary objective of the study will be determination of present and past infection by B. pertussis via IgG testing as well as PCR of nasal swab and how this may relate to the Alzheimer biomarker responses to Tdap vaccination.