I've heard taking at least 1000mg vitamin C prior to a chiropractic adjustment can help reduce the effect of the toxin release from the adjustment. Also, drinking plenty of water after would be good to help wash out the toxins.
Yes, apparently viruses, cysts, and other critters can hide in/around the spine and can be released by a variety of things. It is a good thing to get rid of them, but knowing how to handle it is important. Some essential oils are reputed to route out these hidden infections and kill them - and can complement chiropractic treatments nicely for this purpose.
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, Pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Zofran, Pulmicort, Heparin (to flush PICC line), Claritin, Colloidal Silver (used topically), IV Milk Thistle, probiotics.