A single lab spike does not equal better health. We dive into the viral claim that an upper cervical adjustment “boosts immunity” by raising salivary IgA for 30 minutes and unpack what that marker actually reflects at your barrier surfaces. In clear, plain language, we explain why IgA is a frontline "bouncer" for the mouth, sinuses, lungs, and gut—and why a temporary increase can mean everything from an appropriate alarm to simple irritation. The headline sounds exciting; the physiology is mo...