There are more cases of multiple sclerosis (MS) today than 30 or more years ago. The
reasons for this increase are earlier and improved methods of diagnosis, improved treatment,
and longer survival of MS patients. The cause of MS is not yet known. There is some
evidence suggesting that infection in childhood might play a role in the development of MS.
There is no evidence that immunization causes MS.
The cause of chronic fatigue syndrome is not known. Some opponents of vaccination have
alleged that hepatitis B vaccination causes this illness. However studies comparing
vaccinated and unvaccinated adults failed to show any increased risk of chronic fatigue
syndrome after vaccination.
There are many other conditions for which causes are not yet known, such as rheumatoid
arthritis, Crohn's disease, ulcerative colitis and lupus erythematosus (SLE). Since most
persons with these disorders were vaccinated in childhood, it is easy to blame the vaccine
when no other cause can be found. However, there is no evidence to prove that these
conditions are caused by vaccination.
One recent study in England claimed that Crohn's disease (a chronic inflammation of the
small intestines of unknown causes) was more common in young adults who had received
measles vaccine than in unvaccinated adults. However, the methods used in this study had
serious flaws, making it difficult to accept the study's conclusions. Moreover, two other
laboratories have failed to confirm the study's finding that measles virus is present in
samples of inflamed tissue from patients with Crohn's disease.