Vaccine-induced autoimmunity.

The current review summarizes case reports attributing autoimmune diseases and phenomena to various vaccines and suggests potential mechanisms. It has to be emphasized that the demonstration of a temporal relationship does not necessarily attribute autoimmunity to a vaccine. The subject is complicated by the fact that one vaccine may cause more than one autoimmune phenomenon, and a particular immune process may be caused by more than one vaccine. Furthermore, vaccines differ in their pathogenic influence on the immune system. There is no doubt that the new recombinant hepatitis B virus vaccine is different from mumps, measles and rubella vaccines in its ability to trigger autoimmunity, probably by completely different mechanisms. The data summarized here suggest that some vaccines may in rare cases induce autoimmune disorders. The subject of the vaccine-autoimmunity relationship is still obscure; reports have been rare, no laboratory experimentation on this topic has been undertaken, and there are few animal models. For the time being no conclusions can be drawn. Since vaccines are an important prophylactic intervention, the risk-benefit ratio clearly leans towards the advantages of infectious disease prevention. Vaccination routines should not be changed in the healthy population or for patients with known autoimmune disorders. Laborious clinical and laboratory studies should be initiated in order to evaluate the new emerging subject of vaccine-induced autoimmunity.