ZURICH Switzerland's medical regulator recommended patients with serious autoimmune diseases should not use an H1N1 flu vaccine from Novartis, saying there were no studies assessing the innoculation in that population.
Swissmedic said on Wednesday it could not be ruled out that either or both of the adjuvant -- which can enhance the immune response -- and the antigen, or less active ingredient, could lead to an intensifying of autoimmune diseases.
Autoimmune diseases, like rheumatoid arthritis, are caused by an overly active immune system attacking its own body, targeting substances which are normally present.
Novartis was not immediately available to comment.
(Reporting by Sam Cage)