From the bluetongue vaccination campaigns in sheep to overimmunization and ovine ASIA syndrome

The use of vaccines has proven to be very effective in controlling and eradicating infectious diseases, both in veterinary and human medicine; however, vaccines can be also the source of an array of problems caused by procedures such as overimmunization. Bluetongue, an orbiviral disease that affects ruminants, is best controlled by the use of inactivated vaccines. During the last years of the past decade, these vaccines were applied all over Europe to control the spreading of the disease, a goal that was accomplished; however, at the same time, several adverse effects related to the vaccination were reported. Especially in sheep, this vaccination campaign brought out a new cachectic and neurologic disease with harmful consequences for the ovine industry. This disease is now recognized as the ovine version of the autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome) and poses an immense challenge in veterinary medicine, immunology, and vaccinology.