The flu or a reaction to a flu shot could do the same thing. Some recommended the flu shot and others counsel against it. Those who recommend the flu shot do not feel that it produces adverse reactions in patients with multiple sclerosis. Those who counsel against the flu shot, note that viral illness, including those viruses contained in the flu shoot, may produce an acute exacerbation of multiple sclerosis. The flu shot is thus to be avoided to avoid this potential risk.
Viral vaccinations induce interferon production.
It is known, for example, that gamma interferon can produce an increase in attacks of multiple sclerosis. There are probably also other factors. You will need to make a personal decision about the flu shot in consultation with your personal neurologist. Some centers recommend that all patients with multiple sclerosis receive the flu shot. Others feel that the flue shot may stimulate an immune response that could produce new of increased symptoms of multiple sclerosis similar to those that may occur after a viral illness.