Some studies suggest that specific chiropractic care (techniques known as "spinal manipulation therapy") can have benefits to the immune system but studies are scarce, sample sizes small, and methodology and analyses often not of the highest scientific standards. The investigators will example how 36 sessions of chiropractic care over 9-12 weeks can impact immune cell function using a randomized clinical trial design.

Inclusion Criteria:

• Must be between the ages of 18-70.
• Must exhibit vertebral subluxation as measured by a misalignment between one or more vertebrae in relation to normal spinal alignment.
• Have not been sick for the past 3 weeks (immune function).
• Non-smoker.
• Must be able to fast for 10-12 hours.

Exclusion Criteria:

• To have had a chiropractic intervention within the past 6 months.
• To have a condition that may limit the ability to apply a high velocity, low amplitude (HVLA) thrust to the spine such as but not limited to ligament damage, reduced bone density, or other factors that weaken the body's ability to withstand reasonable care (bone cancer, fractures, osteoporosis, etc.)
• To have excessive scoliotic curvature of the spine (> 30º) as measured by identifying the first vertebrae, and the most laterally displaced vertebrae that exhibits tilt below it.