Reassessing the role of Bordetella toxins in inducing experimental allergic encephalitis, revisited the pertussis physiopathology of newborn from hyperimmune mother and the pathology from immune complexes, I searched for anti-Bordetella antibodies and immune circulating complexes in different groups of patients with Multiple Sclerosis (MS). The achieved results demonstrate that, in MS:

• the environmental factor is constituted by Bordetella;
• the individual factor is a muco-ciliar barrier defect;
• there can be three serological types (MS with IgG = remittent; MS with IgM = chronic-evolutive with free intervals; seronegative-MS = chronic-evolutive without free intervals);
• a specific antibiotic treatment is obligatory;
• a rational prophylaxis of relapses is possible.