Sensitization against calf serum proteins as a possible cause of allergic reactions after vaccination

Abstract Sera from patients with typical cutaneous or general allergic reactions and other complaints after application of non-infectious smallpox vaccine have been examined for precipitating antibodies against calf serum and its albumin- or globulin-fraction respectively. Out of 12 patients with typical allergic reactions resembling Arthus-phenomenon or serum sickness, sera from seven of them reacted positively against whole serum and all but one of these to serum globulin. Also, no such antibodies were detected in a group of persons with less typical clinical signs. No antibodies against host tissue or the virus contained in the vaccine were detected by the microtechnique used, antibodies against calf serum albumin were found only in one patient. The possible role of calf serum contamination of viral vaccines for evoking allergic reactions in sensitized persons is discussed briefly.