Humans and infectious microbes have coexisted for as long as humans have walked the earth, and the human immune system has developed an efficient way of dealing with viral and bacterial infections. When infected with a microorganism, the body’s first line of defense is for the cellular or ‘innate’ part of the immune system to mount an inflammatory response.
This response then signals the humoral or ‘learned’ part of the immune system to produce anti-inflammatory chemicals and antibodies that resolve inflammation, so that healing can take place, and establish future resistance to re-infection. A healthy, mature immune system requires an equal balance of cellular and humoral immune system responses. A disruption in this balance can lead to development of allergy and autoimmune disorders, including neuroimmune disorders.
Vaccination attempts to fool the body into believing it has come in contact with the real microorganism that causes infection. But vaccination does not exactly mimic the natural infection process, and often bypasses cellular immunity in favor of humoral immunity.
— Barbara Loe Fisher, co-founder and president of the National Vaccine Information Center (NVIC)
Fisher BL. Vaccines, Autism & Chronic Inflammation: The New Epidemic. 2008.